<a href="https://www.cdc.gov/chronic-disease/about/index.html/" target="_blank">Six in 10</a> Americans are living with at least one chronic disease, and four in 10 Americans have two or more chronic diseases. Some of those diseases, such as hypothyroidism and inflammatory diseases, require individuals to carefully track certain blood tests in order to manage their conditions. Unfortunately, that usually means an onerous cycle of scheduling appointments, traveling to hospitals, and waiting for lab results.Now SiPhox Health is working to help patients and their doctors manage diseases from the comfort of their home with a new kind of blood test based on a silicon photonic chip. The system is the size of a coffee maker and can produce precise readings for 20 different biomarkers.The chip-based device is not yet FDA-cleared, so it is currently only being used for research purposes, but SiPhox also provides mail-in blood testing to thousands of people with chronic diseases, both directly and through other health care and wellness businesses, using approved technology. The company hopes its new system can soon deliver faster results to every home that needs it.“A lot of blood tests aren’t done because they're too inconvenient,” SiPhox founder and former MIT researcher Michael Dubrovsky says. “People skip scheduled blood tests, and physicians don’t always prescribe blood tests because they know it’s inconvenient. That requires them to base their decisions on symptoms, and that’s not optimal for many of these chronic diseases.”Dubrovsky and SiPhox co-founder Diedrik Vermeulen met at MIT while researching photonic chip and laser technology. They see SiPhox’s technology as the latest in a long trend toward smaller and more scalable devices as they are condensed onto integrated chips.“Biolabs typically do blood testing with these large instruments that are full of optics, lasers, lenses, mirrors, and all these very expensive features,” Vermeulen says. “We don’t change any of the main features. We leave all the optics the same, but we miniaturize it onto our chips and make it so scalable that you can ship it to homes. It’s like how computers used to be the size of a room and you could only find them in high-end universities — now they’re all on a chip. We’re doing the same for blood testing.”<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1731976955976-MIT-SiPhox-03-press.jpg" style="width: 100%px;" class="fr-fic fr-dib">"We can offer a new way for people to access health care in their home," Vermeulen says. Pictured is an example of the package sent to clients. Image: Courtesy of SiPhox Health<h2>Photonic chips with electric properties</h2>Dubrovsky and Vermeulen met through the MIT ecosystem in 2019. Vermeulen had worked in MIT’s Silicon Photonics Group within the Research Laboratory of Electronics and Dubrovsky was working in the MIT Materials for Micro and Nano Systems group.The two quickly bonded over a new way to approach optical chips.“We had this idea of doing optical chips more like a printed circuit board,” Vermeulen explains. “Electrical chips incorporate a lot of chips on one circuit board, but optical chips typically do everything with a single chip. We wanted to combine optical chips into a new kind of circuit board.”The founders met regularly in the Martin Trust Center for MIT Entrepreneurship to refine their approach. In February of 2020, they started filing patents and receiving guidance from MIT professors. They also entered the START.nano program, which helps early-stage companies accelerate their innovations by giving them access to MIT.nano’s laboratories and equipment.The same lasers that are used to mass produce traditional silicon chips can be used to manufacture SiPhox’s integrated photonic silicon chips. Each 1-millimeter chip contains lenses, polarizers, modulators, splitters, and other optical components you’d see in a traditional lab-based system, but SiPhox’s chips are cheap enough to be single-use.Just as the founders were deciding on the first application for their new chip, the Covid-19 pandemic hit. They took that as a sign.“We decided to focus on biosensing, with one of our chips being disposable and the other one being reusable,” Vermeulen says.The founders worked to detect infectious disease with their chips but realized the technology was better suited for high-fidelity blood testing.“I worked a lot on tunable lasers at MIT, and we use a slightly different approach to lasers at SiPhox,” Vermeulen says. “We applied all of the lessons we learned at MIT to design something from scratch.”SiPhox’s chip testing system works with third-party arm patches that people already use to collect blood samples at home. Dubrovsky likens the system to a Nespresso machine in which users simply place a pod into the machine and press a button. Each of SiPhox’s disposable cartridges contains an array of photonic immunoassay sensors that can be used to detect specific proteins or hormones.The system includes a dashboard that can be viewed by a physician or the patient themselves to get biomarker data at home. The dashboard also provides historic data and educational content about the biomarkers measured. SiPhox also uses large language models to parse third-party blood test data, allowing users to track traditional blood tests in the same dashboard.Because the approach makes use of semiconductor lasers and silicon chips, the founders say a single traditional chip manufacturing facility, or fab, could produce 1 billion of SiPhox’s chips every month.“Our technology is very scalable because it’s all on a chip,” Vermeulen says. “There are only two ways to really scale something: You can do injection molding; that’s how you produce billions of plastic cups, for instance. But if you want to scale something very complex, you have to put it on a silicon chip.”<h2>A platform for health</h2>The founders believe their technology could enable a world where tracking biomarkers is as easy as brushing your teeth. That would have huge implications for the tens of millions of Americans who need to get regular blood tests to manage chronic diseases.“For people with inflammatory diseases, tracking inflammation levels is very important because they can develop resistance to their medicine,” Dubrovsky says. “Once they experience symptoms of a flare-up, it’s very hard to reverse. And these symptoms can be horrible, so catching it early is really important.”To gain FDA clearance, SiPhox plans to begin studies in coming months, but its system’s accuracy has already been validated by third parties, and the company’s Burlington, Massachusetts, facility is capable of manufacturing about 10,000 of its cartridges per month.Once SiPhox gains FDA clearance, it plans to partner with health care systems, health insurers, employers, and mail-in blood testing companies to help people everywhere track their health.“We can offer a new way for people to access health care in their home,” Vermeulen says. “Once they have our blood testing device, whether for a chronic disease or something else, anytime they want telehealth-enabled by blood testing, they can use our device, similar to how Apple users have access to third-party apps from many different service providers. Siphox users will have access to curated third-party services built on top of the core blood testing capability.”

SiPhox Health is working to help patients and their doctors manage diseases from the comfort of their home with a new kind of blood test based on a silicon photonic chip. Image: Courtesy of SiPhox Health

The startup SiPhox, founded by two former MIT researchers, has developed an integrated photonic chip for high-quality, home-based blood testing.

Bringing lab testing to the home

<html><head></head><body>The future of photonic integrated circuits (PICs) is brighter than ever, and the Global Photonics Engineering Contest is set to drive this momentum forward. Hosted together by PhotonDelta and Wevolver, this contest calls on tech-savvy engineers and innovators to tackle the engineering challenges of tomorrow. Launched against the backdrop of this year’s PIC Summit, which saw over 700 industry leaders, including government officials, semiconductor experts, and photonics professionals to discuss the future of the photonic chip industry, the contest underscores the urgent need to advance photonic chip technologies to address critical societal challenges.<h2 dir="ltr">The Global Photonics Engineering Challenge: Driving Innovation</h2>The Global Photonics Engineering Challenge is a pioneering contest that is shaping the future of photonic integrated circuit (PIC) engineering. Hosted by PhotonDelta, an industry accelerator of the development of the photonic chip ecosystem, and Wevolver, a platform dedicated to democratizing engineering innovation, the contest highlights the critical role photonics will play in the future of multiple industries. It is further supported by key actors in the integrated photonics industry: imec, PHIX Photonics Assembly, SMART Photonics, BRIGHT integrated Photonics, Epiphany, and LioniX International.The challenge invites participants to design groundbreaking PIC-based solutions across a broad spectrum of industries, from telecommunications and medical devices to quantum computing and environmental monitoring. With the competition focusing on next-generation PICs, participants are encouraged to explore practical applications that could redefine the technological landscape.Winners will not only gain €50,000 of services from the PhotonDelta ecosystem to make their idea market-ready and a chance to receive up to €2 million in pre-seed funding, but will also have the opportunity to get recognition among the global photonics community and collaborate with industry leaders to develop their idea.&nbsp;The competition is open for applications from now until the 3rd of March for any one from startups, established companies, engineers, researchers, students, and academic organizations working on next-generation photonic circuits that tackle pressing societal challenges in areas such as sustainability, healthcare and climate change.&nbsp;This challenge is more than a contest—it’s a way to help shape the future of technology, enabling engineers to demonstrate the potential of PICs in addressing critical societal and industrial challenges.<a href="https://www.wevolver.com/article/global-photonics-engineering-contest" target="_blank" rel="noopener noreferrer" id="isPasted" class="button-main-action">Read more and apply</a><h3 dir="ltr">Why the Challenge Matters</h3>This year's PIC Summit highlighted the need for innovation and collaboration to continue advancing the applications of integrated photonics, &nbsp;as it is rapidly becoming a critical component in many industries, thanks to its ability to provide ultra-fast data transmission, energy-efficient computing, and compact hardware. However, the design and integration of PICs remain complex. Engineers must overcome significant challenges related to fabrication, power consumption, and scalability. The Global Photonics Engineering Challenge serves as a platform for innovators to present creative solutions to these challenges while showcasing the untapped potential of photonic technologies.For engineers, this challenge offers an opportunity to work on cutting-edge technology, collaborate with leading professionals, and contribute to transformative solutions. It highlights the critical role that PIC engineering plays in solving global problems and drives home the importance of continuing advancements in this field.<h2 dir="ltr">Key Highlights and Insights from PIC Summit 2024</h2>The&nbsp;PIC Summit 2024&nbsp;was a hub of cutting-edge discussions, bringing together over 700 leaders from governments, the semiconductor industry, and the photonic chip sector. The focus of the summit was to explore how photonics can drive the next wave of technological advancements. Leaders emphasized the need for greater European cooperation to remain competitive in the global market and stressed the importance of government support to fuel innovation.<h3 dir="ltr">Three Key Themes from This Year’s PIC Summit:</h3><ol><li dir="ltr">Industry Roadmaps and Trends: Discussions on the global photonics roadmap provided valuable insights into where the industry is headed. Experts delved into the latest advancements in materials, fabrication techniques, and applications that are driving the photonic sector forward.</li><li dir="ltr">The Role of Startups and SMEs: This year's PIC Summit highlighted the crucial role of small and medium-sized enterprises (SMEs) and startups in pushing the boundaries of PIC technology. The summit saw several sessions where start ups pitch their applications in biosensing, quantum computing and imaging.</li><li dir="ltr">Quantum Computing and Photonics: With the rise of quantum computing, photonics is being explored as a viable technology to enable the creation of quantum bits (qubits) at scale. Sessions dedicated to this topic revealed how photonics could overcome current quantum computing challenges, particularly in scaling and error correction.</li></ol><h3 dir="ltr">Be a Part of The Future of Photonic Integrated Circuit Engineering: Apply to the Global Photonics Engineering Challenge</h3>The PIC Summit 2024 and the&nbsp;Global Photonics Engineering Challenge&nbsp;represent a monumental shift in how the world views photonic integrated circuits. As governments, industries, and engineers come together to drive the next wave of photonic innovation, the future holds immense potential for transformative applications in a variety of fields.For engineers, this is an exciting time. Whether you are involved in telecommunications, computing, healthcare, or environmental technologies, photonic integrated circuits are set to change the game. The&nbsp;Global Photonics Engineering Challenge&nbsp;offers a unique opportunity to contribute to this revolution while gaining recognition in an industry that is poised for exponential growth.<a href="https://www.wevolver.com/article/global-photonics-engineering-contest" target="_blank" rel="noopener noreferrer" class="button-main-action">&nbsp;Read more and apply</a></body></html>

Industry Leaders Emphasize the Role of Innovation and Cooperation in Developing Integrated Photonic Applications to Address Societal Challenges.

The Future of Photonics: Global Engineering Challenge Officially Launced at PIC Summit 2024

MIT researchers have developed a miniature, chip-based “tractor beam,” like the one that captures the Millennium Falcon&nbsp;in the film “Star Wars,” that could someday help biologists and clinicians study DNA, classify cells, and investigate the mechanisms of disease.Small enough to fit in the palm of your hand, the device uses a beam of light emitted by a silicon-photonics chip to manipulate particles millimeters away from the chip surface. The light can penetrate the glass cover slips that protect samples used in biological experiments, enabling cells to remain in a sterile environment.Traditional optical tweezers, which trap and manipulate particles using light, usually require bulky microscope setups, but chip-based optical tweezers could offer a more compact, mass manufacturable, broadly accessible, and high-throughput solution for optical manipulation in biological experiments.However, other similar integrated optical tweezers can only capture and manipulate cells that are very close to or directly on the chip surface. This contaminates the chip and can stress the cells, limiting compatibility with standard biological experiments.Using a system called an integrated optical phased array, the MIT researchers have developed a new modality for integrated optical tweezers that enables trapping and tweezing of cells more than a hundred times further away from the chip surface.“This work opens up new possibilities for chip-based optical tweezers by enabling trapping and tweezing of cells at much larger distances than previously demonstrated. It’s exciting to think about the different applications that could be enabled by this technology,” says Jelena Notaros, the Robert J. Shillman Career Development Professor in Electrical Engineering and Computer Science (EECS), and a member of the Research Laboratory of Electronics.Joining Notaros on the paper are lead author and EECS graduate student Tal Sneh; Sabrina Corsetti, an EECS graduate student; Milica Notaros PhD ’23; Kruthika Kikkeri PhD ’24; and Joel Voldman, the William R. Brody Professor of EECS. The research&nbsp;<a href="https://www.nature.com/articles/s41467-024-52273-x" target="_blank">appears today in&nbsp;Nature Communications</a>.<h2>A new trapping modality</h2>Optical traps and tweezers use a focused beam of light to capture and manipulate tiny particles. The forces exerted by the beam will pull microparticles toward the intensely focused light in the center, capturing them. By steering the beam of light, researchers can pull the microparticles along with it, enabling them to manipulate tiny objects using noncontact forces.However, optical tweezers traditionally require a large microscope setup in a lab, as well as multiple devices to form and control light, which limits where and how they can be utilized.“With silicon photonics, we can take this large, typically lab-scale system and integrate it onto a chip. This presents a great solution for biologists, since it provides them with optical trapping and tweezing functionality without the overhead of a complicated bulk-optical setup,” Notaros says.But so far, chip-based optical tweezers have only been capable of emitting light very close to the chip surface, so these prior devices could only capture particles a few microns off the chip surface. Biological specimens are typically held in sterile environments using glass cover slips that are about 150 microns thick, so the only way to manipulate them with such a chip is to take the cells out and place them on its surface.However, that leads to chip contamination. Every time a new experiment is done, the chip has to be thrown away and the cells need to be put onto a new chip.To overcome these challenges, the MIT researchers developed a silicon photonics chip that emits a beam of light that focuses about 5 millimeters above its surface. This way, they can capture and manipulate biological particles that remain inside a sterile cover slip, protecting both the chip and particles from contamination.<h2>Manipulating light</h2>The researchers accomplish this using a system called an integrated optical phased array. This technology involves a series of microscale antennas fabricated on a chip using semiconductor manufacturing processes. By electronically controlling the optical signal emitted by each antenna, researchers can shape and steer the beam of light emitted by the chip.Motivated by long-range applications like lidar, most prior integrated optical phased arrays weren’t designed to generate the tightly focused beams needed for optical tweezing. The MIT team discovered that, by creating specific phase patterns for each antenna, they could form an intensely focused beam of light, which can be used for optical trapping and tweezing millimeters from the chip’s surface.“No one had created silicon-photonics-based optical tweezers capable of trapping microparticles over a millimeter-scale distance before. This is an improvement of several orders of magnitude higher compared to prior demonstrations,” says Notaros.By varying the wavelength of the optical signal that powers the chip, the researchers could steer the focused beam over a range larger than a millimeter and with microscale accuracy.To test their device, the researchers started by trying to capture and manipulate tiny polystyrene spheres. Once they succeeded, they moved on to trapping and tweezing cancer cells provided by the Voldman group.“There were many unique challenges that came up in the process of applying silicon photonics to biophysics,” Sneh adds.The researchers had to determine how to track the motion of sample particles in a semiautomated fashion, ascertain the proper trap strength to hold the particles in place, and effectively postprocess data, for instance.In the end, they were able to show the first cell experiments with single-beam optical tweezers.Building off these results, the team hopes to refine the system to enable an adjustable focal height for the beam of light. They also want to apply the device to different biological systems and use multiple trap sites at the same time to manipulate biological particles in more complex ways.“This is a very creative and important paper in many ways,” says Ben Miller, Dean’s Professor of Dermatology and professor of biochemistry and biophysics at the University of Rochester, who was not involved with this work. “For one, given that silicon photonic chips can be made at low cost, it potentially democratizes optical tweezing experiments. That may sound like something that only would be of interest to a few scientists, but in reality having these systems widely available will allow us to study fundamental problems in single-cell biophysics in ways previously only available to a few labs given the high cost and complexity of the instrumentation. I can also imagine many applications where one of these devices (or possibly an array of them) could be used to improve the sensitivity of disease diagnostic.”

This chip-based "tractor-beam," which uses an intensely focused beam of light to capture and manipulate biological particles without damaging the cells, could help biologists study the mechanisms of diseases. Credit: Sampson Wilcox, RLE

The tiny device uses a tightly focused beam of light to capture and manipulate cells.

MIT engineers create a chip-based tractor beam for biological particles

Researchers at the Karlsruhe Institute of Technology (KIT) have shown for the first time in Germany how so-called tin defects in diamonds can be controlled very precisely using microwaves. These defects have special optical and magnetic properties and can be used as qubits: the smallest computing units for quantum computers and quantum communication. The results are an important step towards the development of powerful quantum computers and secure quantum communication networks. The researchers report in the journal Physical Review X (DOI: 10.1103/PhysRevX.14.031036).Quantum computers and quantum communication are considered to be pioneering technologies for much faster and more secure data processing and transmission compared to classical computers. The basic information units in quantum computers are qubits, the quantum mechanical equivalent of bits in conventional data processing.While in classical digital communication, for example, laser pulses in a fiber optic cable transport information from A to B, quantum mechanics uses individual photons, which in principle makes the exchange of information secure against eavesdropping. Optically addressable qubits, i.e. qubits that can be controlled or read out using light, are suitable for storing the information in the photons and processing it in quantum computers. These can store and process the quantum states and absorb and release them in the form of photons.<h2>The key point is the stability of the qubits</h2>One of the biggest challenges in developing qubits is to extend their coherence time, i.e. the time in which they can stably store information. The extent to which efficient and scalable quantum computers can be developed depends crucially on whether it is possible to control qubits and keep them stable in such a way that their properties can be used in practice.Doctoral students Ioannis Karapatzakis and Jeremias Resch at the KIT Institute of Physics investigated how a special diamond defect, the so-called tin vacancy center (SnV), can be precisely controlled. The work was part of the projects "Quantum Repeater.Link (QR.X)" for secure fiber-based quantum communication and SPINNING, which is working towards a spin-photon-based diamond-based quantum computer, funded by the Federal Ministry of Education and Research.&nbsp;"A defect in the lattice structure of the carbon atoms of a diamond occurs when atoms are missing or replaced by other atoms, such as tin," explains Karapatzakis. Such defects can be used as qubits for quantum communication because they have special optical and magnetic properties that allow their states, such as the electron spin, to be specifically manipulated using light or microwaves. This can make the defects usable as stable qubits that can store and process information and couple it to photons.&nbsp;<h2>Coherence times could be significantly improved</h2>The diamond qubits have the advantage of being in solid form. This makes them easier to handle than other quantum materials such as atoms in a vacuum. By controlling them with microwaves, Karapatzakis and Resch managed to precisely influence the electron spins of the tin vacancy center qubits and make this visible. "We were able to significantly improve the coherence times of the SnV centers in diamond to up to ten milliseconds," says Resch. This was achieved using the method of dynamic decoupling, which largely minimizes interference factors. Another special feature is that the two doctoral students were able to show for the first time that this type of diamond defect can be controlled very efficiently using superconducting waveguides: These guide the microwaves efficiently to the defects without generating heat. "This is of great importance because these defects are generally researched at very low temperatures close to absolute zero. Increased temperatures would render the qubits unusable," says Karapatzakis."In order to establish communication between two users or, in the future, two quantum computers, I have to be able to transfer the quantum states of the qubit to photons," explains Resch. "By optically reading out the qubit and achieving stable spectral properties, we were able to take an important step in this direction. Our results on controlling tin vacancy centers in diamonds therefore have the potential for an important breakthrough in the further development of secure and efficient quantum communication."&nbsp;<hr>Original publicationIoannis Karapatzakis, Jeremias Resch, Marcel Schrodin, Philipp Fuchs, Michael Kieschnick, Julia Heupel, Luis Kussi, Christoph Sürgers, Cyril Popov, Jan Meijer, Christoph Becher, Wolfgang Wernsdorfer, David Hunger: Phys. Rev. X 14, 27 August 2024, <a href="https://doi.org/10.1103/PhysRevX.14.031036" target="_blank">DOI: 10.1103/PhysRevX.14.031036</a>

The precise control of diamond qubits is a significant step in the development of quantum computers. (Image: Ioannis Karapatzakis, KIT)

Important breakthrough for the development of diamond-based quantum computers

Quantum Communication: Efficient Microwave Control of Diamond Qubits

Design the next generation application with Photonic Chips

Global Photonics Engineering Contest

CMOS and CCD sensors both convert light into electronic signals, with CMOS using pixel-level transistors for faster, energy-efficient processing, while CCD transfers charge across the chip for superior image quality but with slower speed and higher power consumption.

CCD vs CMOS Image Sensors: A Comprehensive Guide for Engineering Professionals

Researchers from ITMO University have <a href="https://pubs.acs.org/doi/10.1021/acs.nanolett.4c01475" target="_blank" id="isPasted">developed</a> a system that can bind and control particles of light and matter. While the bound particles can become a more efficient and eco-friendly substitute for electricity, the device itself may serve as a foundation for advanced computers, communications means, and internet networks.The transition from electronic to photonic devices is one of the most promising and hotly debated technological scenarios in science today. Photonic devices are analogs of everyday devices, such as computers, that use the energy of light particles rather than electricity. Although photonic technology-based devices are more energy-efficient and eco-friendly, as well as faster at transferring and processing information, they are, on the other hand, fairly large when compared to their electronic counterparts. Furthermore, the complete shift would be an expensive and time-consuming process.Therefore, a team of scientists from ITMO University have found the middle ground between photonic and electronic devices. The developed system is controlled by both light and electricity and is powered by interconnected particles of light and excitons, which are bound electron-hole states that form upon the excitation of electrons. Such quasiparticles are known as exciton-polaritons. They are also called “liquid light” because they, on one hand, act as light particles and on the other – possess properties of matter, and can be controlled without much effort. Additionally, the connections between exciton-polaritons are greater than those between photons, making it easier to work with them.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1721610184120-1381703.jpg" style="width: 100%px;" class="fr-fic fr-dib">The device. Photo courtesy of the developersThe team developed a thin plate made of several layers. A photonic crystal – a tantalum oxide lattice covered with a three-atom-thick film of molybdenum diselenide – is placed on a silicon oxide substrate. The plate is activated by a laser beam. When light lands on the device, the lattice is pumped with photons, while electrons in molybdenum diselenide start to transition into an excited state and generate excitons. Then, the photons combine with the excitons and thus produce the said exciton-polaritons.&nbsp;<blockquote>“Our technology makes it possible to not only turn the device on and off, but also regulate two states of exciton-polaritons that correspond to various light wavelengths. The states can be activated simultaneously or independently with varying power. This can be achieved either via a laser beam or by altering the plate’s voltage. We’re also investigating how the states are triggered by voltage and laser power. Knowing that, we can understand when exciton-polaritons transition from one state to another. This is a step towards high-precision particle control,” explains Vasily Kravtsov, a senior researcher at ITMO's Faculty of Physics and an employee at the Frontier Laboratory "Functional Materials for Polaritonic Quantum Logic."</blockquote>The invention may be integrated into complex devices to decrease power consumption and enhance their operational efficiency. Among such devices are optical computers that are based on neural networks and can maximize the potential of AI. The technology can also serve as an interface for internet infrastructures. Additionally, it may become a part of optical regulators and modulators used to transmit and process data, as well as network switches, which transfer energy and direct it to a system’s components.&nbsp;The study was carried out within the Priority 2030 national program at the Frontier Laboratory “Functional Materials for Polaritonic Quantum Logic”

The device. Photo courtesy of the developers

Researchers from ITMO University have developed a system that can bind and control particles of light and matter.

Scientists Develop a Device to Control Light and Matter Quasiparticles

Imagine a portable 3D printer you could hold in the palm of your hand. The tiny device could enable a user to rapidly create customized, low-cost objects on the go, like a fastener to repair a wobbly bicycle wheel or a component for a critical medical operation.Researchers from MIT and the University of Texas at Austin took a major step toward making this idea a reality by demonstrating the first chip-based 3D printer. Their proof-of-concept device consists of a single, millimeter-scale photonic chip that emits reconfigurable beams of light into a well of resin that cures into a solid shape when light strikes it.The prototype chip has no moving parts, instead relying on an array of tiny optical antennas to steer a beam of light. The beam projects up into a liquid resin that has been designed to rapidly cure when exposed to the beam’s wavelength of visible light.By combining silicon photonics and photochemistry, the interdisciplinary research team was able to demonstrate a chip that can steer light beams to 3D print arbitrary two-dimensional patterns, including the letters M-I-T. Shapes can be fully formed in a matter of seconds.In the long run, they envision a system where a photonic chip sits at the bottom of a well of resin and emits a 3D hologram of visible light, rapidly curing an entire object in a single step.This type of portable 3D printer could have many applications, such as enabling clinicians to create tailor-made medical device components or allowing engineers to make rapid prototypes at a job site.“This system is completely rethinking what a 3D printer is. It is no longer a big box sitting on a bench in a lab creating objects, but something that is handheld and portable. It is exciting to think about the new applications that could come out of this and how the field of 3D printing could change,” says senior author Jelena Notaros, the Robert J. Shillman Career Development Professor in Electrical Engineering and Computer Science (EECS), and a member of the Research Laboratory of Electronics.Joining Notaros on the paper are Sabrina Corsetti, lead author and EECS graduate student; Milica Notaros PhD ’23; Tal Sneh, an EECS graduate student; Alex Safford, a recent graduate of the University of Texas at Austin; and Zak Page, an assistant professor in the Department of Chemical Engineering at UT Austin. The&nbsp;<a href="https://www.nature.com/articles/s41377-024-01478-2" target="_blank">research appears today</a> in&nbsp;Nature Light Science and Applications.<h2>Printing with a chip</h2>Experts in silicon photonics, the Notaros group previously developed integrated optical-phased-array systems that steer beams of light using a series of microscale antennas fabricated on a chip using semiconductor manufacturing processes. By speeding up or delaying the optical signal on either side of the antenna array, they can move the beam of emitted light in a certain direction.Such systems are key for lidar sensors, which map their surroundings by emitting infrared light beams that bounce off nearby objects. Recently, the group has focused on systems that emit and steer visible light for augmented-reality applications.They wondered if such a device could be used for a chip-based 3D printer.At about the same time they started brainstorming, the Page Group at UT Austin demonstrated specialized resins that can be rapidly cured using wavelengths of visible light for the first time. This was the missing piece that pushed the chip-based 3D printer into reality.“With photocurable resins, it is very hard to get them to cure all the way up at infrared wavelengths, which is where integrated optical-phased-array systems were operating in the past for lidar,” Corsetti says. “Here, we are meeting in the middle between standard photochemistry and silicon photonics by using visible-light-curable resins and visible-light-emitting chips to create this chip-based 3D printer. You have this merging of two technologies into a completely new idea.”Their prototype consists of a single photonic chip containing an array of 160-nanometer-thick optical antennas. (A sheet of paper is about 100,000 nanometers thick.) The entire chip fits onto a U.S. quarter.When powered by an off-chip laser, the antennas emit a steerable beam of visible light into the well of photocurable resin. The chip sits below a clear slide, like those used in microscopes, which contains a shallow indentation that holds the resin. The researchers use electrical signals to nonmechanically steer the light beam, causing the resin to solidify wherever the beam strikes it.<h2>A collaborative approach</h2>But effectively modulating visible-wavelength light, which involves modifying its amplitude and phase, is especially tricky. One common method requires heating the chip, but this is inefficient and takes a large amount of physical space.Instead, the researchers used liquid crystal to fashion compact modulators they integrate onto the chip. The material’s unique optical properties enable the modulators to be extremely efficient and only about 20 microns in length.A single waveguide on the chip holds the light from the off-chip laser. Running along the waveguide are tiny taps which tap off a little bit of light to each of the antennas.The researchers actively tune the modulators using an electric field, which reorients the liquid crystal molecules in a certain direction. In this way, they can precisely control the amplitude and phase of light being routed to the antennas.But forming and steering the beam is only half the battle. Interfacing with a novel photocurable resin was a completely different challenge.The Page Group at UT Austin worked closely with the Notaros Group at MIT, carefully adjusting the chemical combinations and concentrations to zero-in on a formula that provided a long shelf-life and rapid curing.In the end, the group used their prototype to 3D print arbitrary two-dimensional shapes within seconds.Building off this prototype, they want to move toward developing a system like the one they originally conceptualized — a chip that emits a hologram of visible light in a resin well to enable volumetric 3D printing in only one step.“To be able to do that, we need a completely new silicon-photonics chip design. We already laid out a lot of what that final system would look like in this paper. And, now, we are excited to continue working towards this ultimate demonstration,” Jelena Notaros says.

The tiny device could enable a user to rapidly create customized, low-cost objects on the go, like a fastener to repair a wobbly bicycle wheel or a component for a critical medical operation. Credit: Sampson Wilcox, RLE

Smaller than a coin, this optical device could enable rapid prototyping on the go.

Researchers demonstrate the first chip-based 3D printer

Imaging the hot turbulence of aircraft propulsion systems may now be possible with sturdy sheets of composite materials that twist light beams, according to research led by the University of Michigan and Air Force Research Laboratory.The sheets were produced with a new manufacturing method that opens possibilities beyond aircraft design, as it enables new classes of materials to be used in polarization optics. While the team demonstrated high temperature tolerance, new mechanical, electrical and physical properties are expected to emerge as well—with potential applications in energy, sensors for vehicles and robots, and space exploration.“Combining multiple functionalities into 2D materials opens up a world of possibilities,” said <a href="https://mrs.digitellinc.com/b/sp/dhriti-nepal-34987" target="_blank" rel="noreferrer noopener">Dhriti Nepal</a>, senior research materials engineer at the Air Force Research Laboratory and a co-corresponding author of the study published recently in Nature.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1717115403757-nick-and-jun.jpg" style="width: 100%px;" class="fr-fic fr-dib">Nicholas Kotov, the Irving Langmuir Distinguished University Professor of Chemical Sciences and Engineering, and Jun Lu, an adjunct research investigator, present their light-twisting materials in their chemical engineering laboratory. Photo credit: Brenda Ahearn, Michigan Engineering.“Think of a butterfly’s wings, which allow it to fly, regulate temperature, and reflect light to produce specific colors for attracting mates and avoiding predators. This technique provides new design opportunities for creating multifunctional devices capable of anything one can imagine.”The key is arranging nanomaterials that don’t twist light on their own onto layers that turn light waves into either left- or right-handed spirals, known as circular polarizations. In the aircraft example, turbulence created by the engine spins the light, which is then filtered through the material for imaging. Today, devices like <a href="https://www.hull.ac.uk/work-with-us/more/media-centre/news/2022/the-chemistry-behind-your-lcd-flat-screen-devices-how-a-scientist-changed-the-world" target="_blank" rel="noreferrer noopener">LCD screens</a> and <a href="https://www.qats.com/Products/Instruments/Surface-Thermography/TLC-100" target="_blank" rel="noreferrer noopener">thermochromic paints</a> already control the twist and orientation of light waves using <a href="https://pubs.acs.org/doi/full/10.1021/acsaom.3c00282?casa_token=PCLN4MaiV1UAAAAA%3Aasa8_oPhbylNiDNzYH77VxzwONVZ49_8EuTBj9MZWHJoD8N-Q7GxEwqhEWFR_UdFuonKP_FvpcYviPk" target="_blank" rel="noreferrer noopener">liquid crystals</a>, but they melt not far above ambient temperatures.“There could be situations in which you want to twist light outside the normal operating temperatures of liquid crystals. Now, we can make light-polarizing devices for those kinds of settings,” said <a href="https://che.engin.umich.edu/people/kotov-nicholas/" target="_blank" rel="noreferrer noopener">Nicholas Kotov</a>, the Irving Langmuir Distinguished University Professor of Chemical Sciences and Engineering at U-M and lead author of the study.The new material can twist light at 250 degrees Celsius, and through the imaging of turbulence in aircraft engines and other applications, it could enable aerospace engineers to improve designs for better aircraft flight performance.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1717115422648-composite-sheet-featured-e1717078357451+%281%29.jpg" style="width: 100%px;" class="fr-fic fr-dib">This composite film can twist light into a spiral, thanks to microscopic grooves that cause horizontally and vertically oscillating light waves to pass through the film out of phase. Unlike existing materials that can do this, the film maintains its light-twisting properties when heated up to 250 degrees Celsius. Photo credit: Brenda Ahearn, Michigan Engineering.“Future aerospace systems continue to push the edge of technical feasibility. These low-cost optical materials afford modularity, which is crucial for optimizing solutions for a broad range of future technologies,” said <a href="https://www.af.mil/About-Us/Biographies/Display/Article/1733591/dr-richard-a-vaia/" target="_blank" rel="noreferrer noopener" id="isPasted">Richard Vaia</a>, materials and manufacturing chief scientist at the Air Force Research Laboratory and a corresponding author of the study.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1717115446434-composite-sheet-fire.jpg" style="width: 100%px;" class="fr-fic fr-dib">To measure how well the film twists light at high temperatures, U-M researchers use a small flame as a light and heat source. Photo credit: Brenda Ahearn, Michigan Engineering.To make the materials, the researchers put microscopic grooves into a plastic sheet and covered it with several layers of tiny, flat particles with a diameter 10,000 times smaller than a millimeter. These particles were held in place with alternating layers of a molecular adhesive, and they could be made from any material that can be made into flat nanoparticles. For their heat-tolerant materials, the researchers used ceramic-like materials called MXenes.As light moves through the material, it divides into two beams, one with horizontally oscillating waves and another with vertically oscillating waves. The vertical waves pass through faster than the horizontal waves. As a result, the waves exit out of phase and appear as a spiral of light. The angle of the grooves determines the direction in which the light spirals, and layers of silver nanowires can help ensure the light spirals solely to the left or right.“Our calculations suggest that the optical properties didn’t come from the nanoplates themselves, but from their orientation on the grooves caused by our fabrication process,” said André Farias de Moura, associate professor of chemistry at the Federal University of São Carlos and a co-corresponding author of the study.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1717115465598-Jun-fire.jpg" style="width: 100%px;" class="fr-fic fr-dib">Jun Lu, an adjunct research investigator working in Kotov’s lab and the study’s first author, demonstrates how he uses a fire to test a film’s ability to twist light at high temperatures. Photo credit: Brenda Ahearn, Michigan Engineering.The research was funded by the National Science Foundation Science and Technology&nbsp;<a href="https://compass.engin.umich.edu/" target="_blank" rel="noreferrer noopener">Center for Complex Particle Systems</a>, U.S. Department of Defense, U.S. Office of Naval Research, U.S. Air Force Office of Scientific Research, Brazil’s National Council for Scientific and Technological Development, as well as the São Paulo Research Foundation. The materials were studied at the&nbsp;<a href="https://mc2.engin.umich.edu/" target="_blank" rel="noreferrer noopener">Michigan Center for Materials Characterization</a>.Felippe Colombari from the Brazilian Biorenewables National Laboratory also contributed to the study. Nicholas Kotov is also the Joseph B. and Florence V. Cejka Professor of Engineering and a professor of macromolecular science and engineering.Kotov filed a patent with the help of Innovation Partnerships at U-M, and his company Photon Semantics LLC, a U-M startup, is planning to license the technology. Kotov and the University of Michigan have a financial interest in Photon Semantics LLC.

New manufacturing method builds tougher materials that were previously considered useless for twisting light into more robust optical devices.

Nanoscale engineering brings light-twisting materials to more extreme settings

Quantum computers hold the promise of being able to quickly solve extremely complex problems that might take the world’s most powerful supercomputer decades to crack.But achieving that performance involves building a system with millions of interconnected building blocks called qubits. Making and controlling so many qubits in a hardware architecture is an enormous challenge that scientists around the world are striving to meet.Toward this goal, researchers at MIT and MITRE have demonstrated a scalable, modular hardware platform that integrates thousands of interconnected qubits onto a customized integrated circuit. This “quantum-system-on-chip” (QSoC) architecture enables the researchers to precisely tune and control a dense array of qubits. Multiple chips could be connected using optical networking to create a large-scale quantum communication network.By tuning qubits across 11 frequency channels, this QSoC architecture allows for a new proposed protocol of “entanglement multiplexing” for large-scale quantum computing.The team spent years perfecting an intricate process for manufacturing two-dimensional arrays of atom-sized qubit microchiplets and transferring thousands of them onto a carefully prepared complementary metal-oxide semiconductor (CMOS) chip. This transfer can be performed in a single step.“We will need a large number of qubits, and great control over them, to really leverage the power of a quantum system and make it useful. We are proposing a brand new architecture and a fabrication technology that can support the scalability requirements of a hardware system for a quantum computer,” says Linsen Li, an electrical engineering and computer science (EECS) graduate student and lead author of a paper on this architecture.Li’s co-authors include Ruonan Han, an associate professor in EECS, leader of the Terahertz Integrated Electronics Group, and member of the Research Laboratory of Electronics (RLE); senior author Dirk Englund, professor of EECS, principal investigator of the Quantum Photonics and Artificial Intelligence Group and of RLE; as well as others at MIT, Cornell University, the Delft Institute of Technology, the U.S. Army Research Laboratory, and the MITRE Corporation. The <a href="https://www.nature.com/articles/s41586-024-07371-7" target="_blank">paper appears today</a> in Nature.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1717028405505-MIT-Quantum_Chip-01-press+%281%29.jpg" style="width: 100%px;" class="fr-fic fr-dib">Researchers developed a modular fabrication process to produce a quantum-system-on-chip which integrates an array of artificial atom qubits onto a semiconductor chip. Image: Sampson Wilcox and Linsen Li, RLE<h2>Diamond microchiplets</h2>While there are many types of qubits, the researchers chose to use diamond color centers because of their scalability advantages. They previously used such qubits to <a href="https://news.mit.edu/2020/scaling-quantum-chip-0708" target="_blank">produce integrated quantum chips</a> with photonic circuitry.Qubits made from diamond color centers are “artificial atoms” that carry quantum information. Because diamond color centers are solid-state systems, the qubit manufacturing is compatible with modern semiconductor fabrication processes. They are also compact and have relatively long coherence times, which refers to the amount of time a qubit’s state remains stable, due to the clean environment provided by the diamond material.In addition, diamond color centers have photonic interfaces which allows them to be remotely entangled, or connected, with other qubits that aren’t adjacent to them.“The conventional assumption in the field is that the inhomogeneity of the diamond color center is a drawback compared to identical quantum memory like ions and neutral atoms. However, we turn this challenge into an advantage by embracing the diversity of the artificial atoms: Each atom has its own spectral frequency. This allows us to communicate with individual atoms by voltage tuning them into resonance with a laser, much like tuning the dial on a tiny radio,” says Englund.This is especially difficult because the researchers must achieve this at a large scale to compensate for the qubit inhomogeneity in a large system.To communicate across qubits, they need to have multiple such “quantum radios” dialed into the same channel. Achieving this condition becomes near-certain when scaling to thousands of qubits. To this end, the researchers surmounted that challenge by integrating a large array of diamond color center qubits onto a CMOS chip which provides the control dials. The chip can be incorporated with built-in digital logic that rapidly and automatically reconfigures the voltages, enabling the qubits to reach full connectivity.“This compensates for the in-homogenous nature of the system. With the CMOS platform, we can quickly and dynamically tune all the qubit frequencies,” Li explains.<h2>Lock-and-release fabrication</h2>To build this QSoC, the researchers developed a fabrication process to transfer diamond color center “microchiplets” onto a CMOS backplane at a large scale.They started by fabricating an array of diamond color center microchiplets from a solid block of diamond. They also designed and fabricated nanoscale optical antennas that enable more efficient collection of the photons emitted by these color center qubits in free space.Then, they designed and mapped out the chip from the semiconductor foundry. Working in the MIT.nano cleanroom, they post-processed a CMOS chip to add microscale sockets that match up with the diamond microchiplet array.They built an in-house transfer setup in the lab and applied a lock-and-release process to integrate the two layers by locking the diamond microchiplets into the sockets on the CMOS chip. Since the diamond microchiplets are weakly bonded to the diamond surface, when they release the bulk diamond horizontally, the microchiplets stay in the sockets.“Because we can control the fabrication of both the diamond and the CMOS chip, we can make a complementary pattern. In this way, we can transfer thousands of diamond chiplets into their corresponding sockets all at the same time,” Li says.The researchers demonstrated a 500-micron by 500-micron area transfer for an array with 1,024 diamond nanoantennas, but they could use larger diamond arrays and a larger CMOS chip to further scale up the system. In fact, they found that with more qubits, tuning the frequencies actually requires less voltage for this architecture.“In this case, if you have more qubits, our architecture will work even better,” Li says.The team tested many nanostructures before they determined the ideal microchiplet array for the lock-and-release process. However, making quantum microchiplets is no easy task, and the process took years to perfect.“We have iterated and developed the recipe to fabricate these diamond nanostructures in MIT cleanroom, but it is a very complicated process. It took 19 steps of nanofabrication to get the diamond quantum microchiplets, and the steps were not straightforward,” he adds.Alongside their QSoC, the researchers developed an approach to characterize the system and measure its performance on a large scale. To do this, they built a custom cryo-optical metrology setup.Using this technique, they demonstrated an entire chip with over 4,000 qubits that could be tuned to the same frequency while maintaining their spin and optical properties. They also built a digital twin simulation that connects the experiment with digitized modeling, which helps them understand the root causes of the observed phenomenon and determine how to efficiently implement the architecture.In the future, the researchers could boost the performance of their system by refining the materials they used to make qubits or developing more precise control processes. They could also apply this architecture to other solid-state quantum systems.This work was supported by the MITRE Corporation Quantum Moonshot Program, the U.S. National Science Foundation, the U.S. Army Research Office, the Center for Quantum Networks, and the European Union’s Horizon 2020 Research and Innovation Program.

Researchers developed a modular fabrication process to produce a quantum-system-on-chip which integrates an array of artificial atom qubits onto a semiconductor chip. Image: Sampson Wilcox and Linsen Li, RLE

A new quantum-system-on-chip enables the efficient control of a large array of qubits, moving toward practical quantum computing.

Modular, scalable hardware architecture for a quantum computer

In this episode, discuss how big of a problem lead contaminated water still is across the world and how a collaboration between MIT & Nanyang University plans to tackle it with a highly accurate and inexpensive water pollution sensor.

Podcast: Is Your Drinking Water Safe? This Sensor Has The Answer

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/076af450-88d2-4524-8ec5-df4c5234a282?dark=false" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>Engineers at MIT, Nanyang Technological University, and several companies have developed a compact and inexpensive technology for detecting and measuring lead concentrations in water, potentially enabling a significant advance in tackling this persistent global health issue.The World Health Organization estimates that 240 million people worldwide are exposed to drinking water that contains unsafe amounts of toxic lead, which can affect brain development in children, cause birth defects, and produce a variety of neurological, cardiac, and other damaging effects. In the United States alone, an estimated 10 million households still get drinking water delivered through lead pipes.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzE1NzM1MzgzNjM4LU1JVC1MZWFkLURldGVjdGlvbi0wMi1wcmVzcy5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib">Testing setup of the photonic chip sensor, including microfluidic chamber to transport analyte solutions and optical fibers on the sides to measure the photonic response of the chip. Image: Courtesy of the researchers“It’s an unaddressed public health crisis that leads to over 1 million deaths annually,” says Jia Xu Brian Sia, an MIT postdoc and the senior author of the paper describing the new technology.But testing for lead in water requires expensive, cumbersome equipment and typically requires days to get results. Or, it uses simple test strips that simply reveal a yes-or-no answer about the presence of lead but no information about its concentration. Current EPA regulations require drinking water to contain no more that 15 parts per billion of lead, a concentration so low it is difficult to detect.The new system, which could be ready for commercial deployment within two or three years, could detect lead concentrations as low as 1 part per billion, with high accuracy, using a simple chip-based detector housed in a handheld device. The technology gives nearly instant quantitative measurements and requires just a droplet of water.The findings are described in a <a href="https://www.nature.com/articles/s41467-024-47938-6" target="_blank">paper appearing today</a> in the journal Nature Communications, by Sia, MIT graduate student and lead author Luigi Ranno, Professor Juejun Hu, and 12 others at MIT and other institutions in academia and industry.The team set out to find a simple detection method based on the use of photonic chips, which use light to perform measurements. The challenging part was finding a way to attach to the photonic chip surface certain ring-shaped molecules known as crown ethers, which can capture specific ions such as lead. After years of effort, they were able to achieve that attachment via a chemical process known as Fischer esterification. “That is one of the essential breakthroughs we have made in this technology,” Sia says.In testing the new chip, the researchers showed that it can detect lead in water at concentrations as low as one part per billion. At much higher concentrations, which may be relevant for testing environmental contamination such as mine tailings, the accuracy is within 4 percent.The device works in water with varying levels of acidity, ranging from pH values of 6 to 8, “which covers most environmental samples,” Sia says. They have tested the device with seawater as well as tap water, and verified the accuracy of the measurements.In order to achieve such levels of accuracy, current testing requires a device called an inductive coupled plasma mass spectrometer. “These setups can be big and expensive,” Sia says. The sample processing can take days and requires experienced technical personnel.While the new chip system they developed is “the core part of the innovation,” Ranno says, further work will be needed to develop this into an integrated, handheld device for practical use. “For making an actual product, you would need to package it into a usable form factor,” he explains. This would involve having a small chip-based laser coupled to the photonic chip. “It’s a matter of mechanical design, some optical design, some chemistry, and figuring out the supply chain,” he says. While that takes time, he says, the underlying concepts are straightforward.The system can be adapted to detect other similar contaminants in water, including cadmium, copper, lithium, barium, cesium, and radium, Ranno says. The device could be used with simple cartridges that can be swapped out to detect different elements, each using slightly different crown ethers that can bind to a specific ion.“There’s this problem that people don’t measure their water enough, especially in the developing countries,” Ranno says. “And that’s because they need to collect the water, prepare the sample, and bring it to these huge instruments that are extremely expensive.” Instead, “having this handheld device, something compact that even untrained personnel can just bring to the source for on-site monitoring, at low costs,” could make regular, ongoing widespread testing feasible.Hu, who is the John F. Elliott Professor of Materials Science and Engineering, says, “I’m hoping this will be quickly implemented, so we can benefit human society. This is a good example of a technology coming from a lab innovation where it may actually make a very tangible impact on society, which is of course very fulfilling.”“If this study can be extended to simultaneous detection of multiple metal elements, especially the presently concerning radioactive elements, its potential would be immense,” says Hou Wang, an associate professor of environmental science and engineering at Hunan University in China, who was not associated with this work.Wang adds, “This research has engineered a sensor capable of instantaneously detecting lead concentration in water. This can be utilized in real-time to monitor the lead pollution concentration in wastewater discharged from industries such as battery manufacturing and lead smelting, facilitating the establishment of industrial wastewater monitoring systems. I think the innovative aspects and developmental potential of this research are quite commendable.”Wang Qian, a principal research scientist at the Institute of Materials Research in Singapore, who also was not affiliated with this work, says, “The ability for the pervasive, portable, and quantitative detection of lead has proved to be challenging primarily due to cost concerns. This work demonstrates the potential to do so in a highly integrated form factor and is compatible with large-scale, low-cost manufacturing.”The team included researchers at MIT, at Nanyang Technological University and Temasek Laboratories in Singapore, at the University of Southampton in the U.K., and at companies Fingate Technologies, in Singapore, and Vulcan Photonics, headquartered in Malaysia. The work used facilities at MIT.nano, the Harvard University Center for Nanoscale Systems, NTU’s Center for Micro- and Nano-Electronics, and the Nanyang Nanofabrication Center.

Artist’s impression of the chip surface, showing the on-chip light interferometer used to sense the presence of lead. The lead binding process to the crown ether is shown in the inset. Image: Jia Xu Brian Sia

The chip-scale device could provide sensitive detection of lead levels in drinking water, whose toxicity affects 240 million people worldwide.

Scientists develop an affordable sensor for lead contamination

<section id="isPasted">What do volcanic lava, fire smoke, automobile exhaust fumes, and printer toner have in common? They are all sources of ultrafine particles – particles with a diameter below 100 nanometers, which can pose serious health risks if inhaled. Due to their small size, ultrafine nanoparticles are difficult to detect and measure without expensive and sometimes bulky equipment. To overcome these issues, our researchers have designed a new ultra-sensitive fiber-tip sensor that can detect single particles with diameters down to 50 nanometers in size. In the future, the new sensor will be used in studies to control and evaluate indoor air quality at schools.</section><section tabindex="-1">Nanoparticles are very much part of the everyday world that we call home. For example, in medical testing, devices are available to check for nanoparticles like pathogens and biomarkers for diseases such as cancer.And in drug development, a host of nanoparticles are used to make the drug delivery systems of the future.One class of nanoparticle that is garnering plenty of attention due to its connection with the air that we breathe is the ultrafine particle (UFP), a particle with a diameter below 100 nanometers (nm).Exposure to UFPs – which can be found in smoke, exhaust fumes, and even printer toners – can have serious health risks, especially if these particles are directly inhaled.<section tabindex="-1" id="isPasted">“When UFPs lodge in the lungs, it can pose a severe health risk because once in the lungs, they can absorb toxins that we might breathe in from the air around us. As a result, those toxins then stay in the body,” says <a href="https://www.tue.nl/en/research/researchers/arthur-hendriks" target="_blank">Arthur Hendriks</a>, PhD researcher at the Department of Applied Physics and Science Education. “So, to help prevent this, accurate ways of detecting UFPs are needed so as to monitor indoor air quality.”For example, research on indoor air quality is at the forefront of the <a href="https://www.learnproject-heu.eu/" target="_blank" rel="noreferrer">Horizon Europe project LEARN</a>, which is seeking to control and evaluate indoor air quality at schools and to assess the impact of air quality on children’s health, and part of this requires accurate ways to detect UFPs.<h3>The small-big problem</h3>But detecting UFPs is easier said than done though, and ironically, detection of such small particles relies on the use of large and expensive equipment.“Large and expensive isn’t the answer. We need small, compact, accurate, and cheap devices to make it easier to detect UFPs in factories, hospitals, offices, and schools,” notes Hendriks.</section><section tabindex="-1">So, what is the state-of-the-art now then? “There are sensors based on fiber-optic technologies that can measure liquids and gases with good accuracy. But these sensors not suitable for measuring small particles like UFPs and so their application are limited in that sense,” says Hendriks.&nbsp;‘Lab-on-fiber’ technologies have been used to detect biological cells at the micrometer scale (1000 times larger than the nanometer scale). “But this technology cannot detect single nanoparticles similar in size to UFPs,” says Hendriks.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1714987151109-csm_Hendriks+Nanophotonic-fiber-tip-sensor_5fc4f58556.png" style="width: 100%px;" class="fr-fic fr-dib">SEM image of nanophotonic fiber tip sensor. Source: Arthur Hendriks<h3 id="isPasted">A fiber-tip solution</h3>To meet the demand for a new UFP sensing technology, Hendriks and his TU/e collaborators, which includes Andrea Fiore – professor at the Department of Applied Physics and Science Education, developed a nanophotonic fiber-tip sensor that is sensitive to tiny changes in the environment around the sensor, so much so that it can detect a single nanoparticle the same size as UFPs.“Our sensor design is small and compact, and importantly, it clearly indicates when a detection has occurred,” says Hendriks.The researchers’ sensor work is based on a photonic crystal, a periodic or repeating structure that can reflect light in all directions. “A defect, or error, is then added to the crystal, which is known as a photonic crystal cavity, or PhCC for short,” says Hendriks.A PhCC allows light to be trapped in the crystal for an extended period. Hendriks: “In essence, this is something we call the Q-factor, which is a measure of how well light can be trapped in the defect over time. In our case, the light is confined to a tiny volume, which is below 1 µm3. This is known as the mode volume, and to measure tiny nanoparticles, this needs to be very small.”The researchers were able to place the PhCC on the tip of a fiber using a method developed by Andrea Fiore’s group <a href="https://doi.org/10.1063/5.0021701" target="_blank" rel="noreferrer">back in 2020</a>. When a tiny particle comes close to the PhCC in the crystal, it disturbs the cavity by changing its refractive index. “So, the tiny particle changes the wavelength of the trapped light in the cavity, and we measure this change.”<h2 id="isPasted">CHALLENGES</h2><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1714987186281-csm_Hendriks+Schematic_3e24cc23c3.png" style="width: 100%px;" class="fr-fic fr-dib">The major challenge faced by the researchers was that standard cavities cannot be read out using fibers. A standard cavity on a fiber wouldn’t have worked as light from the fiber will not couple to the cavity.The dream scenario for the researchers was to optimize key factors in the device. First, a high Q-factor was required to allow for more accurate tracking of the wavelength of the cavity. Second, a small mode volume was needed as this allows for the detection of smaller particles. Third, a higher coupling efficiency was a necessity to ensure that light from the fiber can couple to the cavity and back, making it possible to measure the cavity wavelength through the fiber.To solve all these challenges, the researchers used a method developed by researchers at Stanford University to optimize factors such as the Q-factor, mode volume, and coupling efficiency at the same time.<h3 id="isPasted">Unprecedented sensitivity</h3>“Our setup provides unprecedented sensitivity in comparison to previous technologies out there,” points out Hendriks. “Using the sensor, we were able to detect in real-time single UFPs with diameters as low as 50 nanometers. In my opinion, that’s just astounding!”The next step for Hendriks and his colleagues is to suspend the cavities so that the quality factor and the coupling efficiency are even higher, which could result in nanophotonic cavities with best-in-class characteristics, but still readable through the fiber.“Our approach could be used to detect even smaller particles. Or even in other applications like single-photon emitters and nano-optomechanical sensors,” says Hendriks. “And an additional application of the new approach might even be the detection of single biological molecules.”Next up for the UFP sensor will be the European project LEARN, which aims at controlling and evaluating air quality at schools, and it will be done in collaboration with the Microsystems group at TU/e.<hr><h3>Further information</h3>The full paper entitled “Detecting single nanoparticles using fiber-tip nanophotonics” can be read&nbsp;<a href="https://opg.optica.org/optica/fulltext.cfm?uri=optica-11-4-512&id=549037" target="_blank" rel="noreferrer">here</a>.</section></section>

Using an ultrasensitive photonic crystal, TU/e researchers were able to detect single particles down to 50 nanometers in diameter. The new research has just been published in the journal Optica.

A nanophotonic fiber-tip solution to detect the ultrasmall

Quantum simulators (or computers) are a promising means of solving complex computational tasks such as the encryption of data with quantum cryptography. Compared to conventional computers, quantum ones rely not on bits (which can have two states: 1 and 0), but on qubits (which can have many states). It is thanks to this property that quantum computers are expected to be capable of processing all states simultaneously, thus producing solutions faster than regular PCs.One major challenge on the way towards quantum computers is spontaneous emission – the possibility of a qubit being destroyed at any moment by emitting into its environment. This phenomenon shortens the life of quantum states and essentially renders the recording of information impossible in quantum systems. Large atomic structures (containing dozens or hundreds of atoms) are typically used to suppress spontaneous emission. Earlier, scientists from ITMO had <a href="https://www.degruyter.com/document/doi/10.1515/nanoph-2023-0624/html" target="_blank">discovered</a> 2D atomic arrays that can support quantum states of maximal longevity; however, the optimal design of structures with randomly located particles remained unknown.This time, through an optimization of geometry, the physicists were able to acquire structures that can support the quantum states longer by dozens and hundreds of times. For this, they used evolutionary algorithms (AI algorithms that model natural selection processes) to create a program that can predict the appropriate system parameters. Compared to other solutions, in which the atomic structures had predefined geometries, in this one the AI was responsible for identifying the correct atom locations.The suggested solution determines the geometry of molecules made up from ultracold atoms. In a sense, the team has provided a manual for assembling long-lived quantum systems for information recording and storage: the structures predicted by the AI can be used to develop quantum memory algorithms.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1713998613704-1369102.jpg" style="width: 100%px;" class="fr-fic fr-dib">A schematic of the algorithm that determines the optimal design of long-lived quantum structures. Image courtesy of the authorsIn their work, the authors considered two variables: the number of atoms and the minimal space between them. Using the algorithm, they determined the optimal geometry for different interatomic distances: 1D chains and fragments of square and triangle arrays. All of these configurations can support non-radiative – long-lived – quantum states.<blockquote>“There are two paths by which this project may continue. Until now, we have calculated the parameters for single-photon structures; next, we will look for the same things for two-photon tangled states: they can contain twice as much information, as well as be used in quantum communications for information transfer. Moreover, we’d like to improve our algorithm by enabling it to compute systems with a greater number of atoms,” shares&nbsp;Ilya Volkov, one of the paper’s authors and a PhD student at ITMO’s <a href="https://en.itmo.ru/en/faculty/106/fiziko-tehnicheskiy_megafakultet.htm" target="_blank">School of Physics and Engineering</a>.</blockquote>Thanks to this solution, the researchers will be able to extend the recording time of quantum states, thus opening up new possibilities for their application, including the development of quantum computers.<hr><a href="https://pubs.aip.org/aip/apl/article-abstract/124/8/084001/3266785/Non-radiative-configurations-of-a-few-quantum?redirectedFrom=fulltext" target="_blank">Reference</a>: Ilya Volkov, Stanislav Mitsai, Stepan Zhogolev, Danil Kornovan, Alexandra Sheremet, Roman Savelev, Mihail Petrov. Non-radiative configurations of a few quantum emitters ensembles: Evolutionary optimization approach (Applied Physics Letters, 2024)&nbsp;

Physicists from ITMO University have created an AI-based solution to make quantum states remain stable for longer for the processing, reliable recording, and storage of information. This study, described in a recent article in Applied Physics Letters, may help pave the way to quantum computers.

Longer-Lived Quantum States Suggested at ITMO

Researchers at the Georgia Institute of Technology have developed a light-based means of printing nano-sized metal structures that is significantly faster and cheaper than any technology currently available. It is a scalable solution that could transform a scientific field long reliant on technologies that are prohibitively expensive and slow. The breakthrough has the potential to bring new technologies out of labs and into the world.Technological advances in many fields rely on the ability to print metallic structures that are nano-sized — a scale hundreds of times smaller than the width of a human hair. <a href="https://www.me.gatech.edu/faculty/saha" target="_blank">Sourabh Saha</a>, assistant professor in the <a href="https://www.me.gatech.edu/" target="_blank">George W. Woodruff School of Mechanical Engineering</a>, and Jungho Choi, a Ph.D. student in Saha’s lab, developed a technique for printing metal nanostructures that is 480 times faster and 35 times cheaper than the current conventional method.Their research was <a href="https://onlinelibrary.wiley.com/doi/10.1002/adma.202308112" target="_blank">published</a> in the journal Advanced Materials.Printing metal on the nanoscale — a technique known as nanopatterning — allows for the creation of unique structures with interesting functions. It is crucial for the development of many technologies, including electronic devices, solar energy conversion, sensors, and other systems.It is generally believed that high-intensity light sources are required for nanoscale printing. But this type of tool, known as a femtosecond laser, can cost up to half a million dollars and is too expensive for most research labs and small businesses.“As a scientific community, we don’t have the ability to make enough of these nanomaterials quickly and affordably, and that is why promising technologies often stay limited to the lab and don’t get translated into real-world applications,” Saha said.“The question we wanted to answer is, ‘Do we really need a high-intensity femtosecond laser to print on the nanoscale?’ Our hypothesis was that we don’t need that light source to get the type of printing we want.”They searched for a low-cost, low-intensity light that could be focused in a way similar to femtosecond lasers, and chose superluminescent light emitting diodes (SLEDs) for their commercial availability. SLEDs emit light that is a billion times less intense than that of femtosecond lasers.Saha and Choi set out to create an original projection-style printing technology, designing a system that converts digital images into optical images and displays them on a glass surface. The system operates like digital projectors but produces images that are more sharply focused. They leveraged the unique properties of the superluminescent light to generate sharply focused images with minimal defects.They then developed a clear ink solution made up of metal salt and added other chemicals to make sure the liquid could absorb light. When light from their projection system hit the solution, it caused a chemical reaction that converted the salt solution into metal. The metal nanoparticles stuck to the surface of the glass, and the agglomeration of the metal particles creates the nanostructures. Because it is a projection type of printing, it can print an entire structure in one go, rather than point by point — making it much faster.After testing the technique, they found that projection-style nanoscale printing is possible even with low-intensity light, but only if the images are sharply focused. Saha and Choi believe that researchers can readily replicate their work using commercially available hardware. Unlike a pricey femtosecond laser, the type of SLED that Saha and Choi used in their printer costs about $3,000.“At present, only top universities have access to these expensive technologies, and even then, they are located in shared facilities and are not always available,” Choi said. “We want to democratize the capability of nanoscale 3D printing, and we hope our research opens the door for greater access to this type of process at a low cost.”The researchers say their technique will be particularly useful for people working in the fields of electronics, optics, and plasmonics, which all require a variety of complex metallic nanostructures.“I think the metrics of cost and speed have been greatly undervalued in the scientific community that works on fabrication and manufacturing of tiny structures,” Saha said.“In the real world, these metrics are important when it comes to translating discoveries from the lab to industry. Only when we have manufacturing techniques that take these metrics into account will we be able to fully leverage nanotechnology for societal benefit.”<hr>Citation: J. Choi, S. K. Saha, Scalable Printing of Metal Nanostructures through Superluminescent Light Projection. Adv. Mater. 2024, 36, 2308112.DOI: https://doi.org/10.1002/adma.202308112

The researchers developed a light-based means of printing nano-sized metal structures that is 480 times faster and 35 times cheaper than the current conventional method.

photonics

Profiles