Five 91探花 faculty members have been awarded early-career fellowships from the Alfred P. Sloan Foundation. The new Sloan Fellows, announced Feb. 17, are , an assistant professor of physics, , an assistant professor of chemistry, and , an assistant professor of biology, all in the College of Arts & Sciences; , an assistant professor of computer science in the College of Engineering; and , an assistant professor of oceanography in the College of the Environment.聽

Since the first Sloan Research Fellowships were awarded in 1955, and including this year鈥檚 fellows, 136 faculty from 91探花 have received a Sloan Research Fellowship, according to the Sloan Foundation.聽

Sloan Fellowships are open to scholars in seven scientific and technical fields 鈥� chemistry, computer science, Earth system science, economics, mathematics, neuroscience and physics 鈥� and honor early-career researchers whose achievements mark them among the next generation of scientific leaders.聽

The 126鈥疭loan Fellows for 2026鈥痺ere selected by researchers and faculty in the scientific community. Candidates are nominated by their peers, and fellows are selected by independent panels of senior scholars based on each candidate鈥檚 research accomplishments, creativity and potential to become a leader in their field. Each fellow will receive $75,000 to apply toward research endeavors.聽

This year鈥檚 fellows come from 44 institutions across the United States and Canada.聽

Maria 鈥淢asha鈥� Baryakhtar

叠补谤测补办丑迟补谤鈥檚 research in the Department of Physics focuses on theories beyond the established Standard Model of particle physics and on creating new ideas and directions for testing these theories. Such theories address outstanding puzzles in our existing understanding and often predict new, ultralight, feebly interacting particles beyond those we have discovered so far. The existence of these particles can be tested through exquisitely precise experiments in the lab or by observing extreme objects in the sky like black holes and neutron stars.

鈥淢y research program aims to search high and low for new, as yet hidden particles and forces. Because of their nature, these particles require a range of creative search strategies. The directions I am establishing use new technologies and data from the sky to the lab and may be the only way to shed light on the truly dark elements of our universe.鈥�

Matthew R. Golder

骋辞濒诲别谤鈥檚 research in the Department of Chemistry addresses the omnipresent “plastics problems” from two different vantage points. First, the team thinks about new ways to prolong the useful lifetime of commodity materials. The researchers use molecular engineering to keep plastics in use longer before discarding. The Golder Research Group also develops new methods to make and repurpose plastics, with an emphasis on green chemistry and making plastics more recyclable.

“Plastics are paramount to daily life, so there are numerous opportunities to improve performance and mitigate waste. We operate at the interface of fundamental organic chemistry and applied materials science to enhance plastic integrity and sustainability. By doing so, my students really take this mission to heart and constantly dream up new ways to creatively (re)design commodity plastic materials.”聽

Vikram Iyer

滨测别谤鈥檚 research in the Paul G. Allen School of Computer Science & Engineering seeks to address sustainability challenges across the full computing stack from creating recyclable polymers to reimagining the way we build computing hardware by designing AI systems to and . In particular, the group鈥檚 work goes beyond simply reducing energy consumption to quantify and tackle the environmental impacts of materials and manufacturing.聽

鈥�My group both leverages innovations from outside of computing like chemistry and material science to drive sustainability and applies computing techniques from AI to programming languages to fundamentally advance environmental sciences. This work is highly interdisciplinary and takes some extra effort at the beginning for each of us to understand the technologies and methods developed by our collaborators. By doing this, we can come up with completely new ideas that have real world impact like enabling carbon reduction at major companies like Amazon, and creating systems like battery-free robots that push the boundaries of technology.鈥�

Willem Laursen

尝补耻谤蝉别苍鈥檚 research in the Department of Biology is focused on understanding how animals detect and respond to sensory cues in their environment. Using genetic manipulation, neurophysiology and behavioral analyses, the lab’s current focus is to understand how disease vector mosquitoes use sensory cues to locate hosts, mates and egg-laying sites.

“It is an honor to be selected as a Sloan Fellow. This award will support our lab鈥檚 research on the role of the mosquito gustatory, or taste, system in critical behaviors, such as blood feeding. While mosquitoes use all of their senses to efficiently locate hosts, their taste system is surprisingly understudied. By examining the gustatory systems of blood-feeding insects, we hope to better understand how taste cues on the skin and in the blood are detected and used to guide their specialized behaviors, lines of inquiry that could ultimately identify new targets for controlling the spread of disease.”

Frankie Pavia

笔补惫颈补鈥檚 research in the School of Oceanography develops and applies new isotopic techniques to study feedbacks in the Earth system. His work spans the oceanic, atmospheric, lithospheric, and human domains, on timescales ranging from minutes to millennia.

鈥淭he oceans are a repository and reactor for materials originating on land, in the atmosphere, in Earth鈥檚 interior and from outer space. Chemical fingerprints of oceanic interactions with these reservoirs can be unlocked using unique analytical chemistry techniques, especially those involving the precise measurement of isotope ratios. My current research aims to discover new interactions between the oceans and the Earth system in the past, present and future, by pioneering interdisciplinary studies that use measurements of stable and radioactive isotopes to determine how much and how fast the Earth system changes. Current projects involve using cosmic dust to reconstruct sea-ice coverage, sensitively detecting human-derived carbon in the oceans, and understanding the past and future impacts of oceanic calcium carbonate dissolution on storage of atmospheric carbon dioxide.鈥澛�

Contact Baryakhtar at mbaryakh@uw.edu, Golder at goldermr@uw.edu, Iyer at vsiyer@cs.washington.edu, Laursen at wlaursen@uw.edu, and Pavia at fjpavia@uw.edu.

A recent found that the world generated 137 billion pounds of electronic waste in 2022, an 82% increase from 2010. Yet less than a quarter of 2022鈥檚 e-waste was recycled. While many things impede a sustainable afterlife for electronics, one is that we don鈥檛 have systems at scale to recycle the found in nearly all electronic devices.

PCBs 鈥� which house and interconnect chips, transistors and other components 鈥� typically consist of layers of thin glass fiber sheets coated in hard plastic and laminated together with copper. That plastic can鈥檛 easily be separated from the glass, so PCBs often pile up in landfills, where their chemicals can seep into the environment. Or they鈥檙e burned to extract their electronics鈥� valuable metals like gold and copper. This burning, , is wasteful and can be toxic 鈥� especially for those doing the work without proper protections.

A team led by researchers at the 91探花 developed a new PCB that performs on par with traditional materials and can be recycled repeatedly with negligible material loss. Researchers used a solvent that transforms a type of 鈥� a cutting-edge class of sustainable polymers 鈥� to a jelly-like substance without damaging it, allowing the solid components to be plucked out for reuse or recycling.

The vitrimer jelly can then be repeatedly used to make new, high-quality PCBs, unlike conventional plastics that degrade significantly with each recycling. With these 鈥渧PCBs鈥� (vitrimer printed circuit boards), researchers recovered 98% of the vitrimer and 100% of the glass fiber, as well as 91% of the solvent used for recycling.

The researchers published April 26 in Nature Sustainability.

鈥淧CBs make up a pretty large fraction of the mass and volume of electronic waste,鈥� said co-senior author , a 91探花assistant professor in the Paul G. Allen School of Computer Science & Engineering. 鈥淭hey鈥檙e constructed to be fireproof and chemical-proof, which is great in terms of making them very robust. But that also makes them basically impossible to recycle. Here, we created a new material formulation that has the electrical properties comparable to conventional PCBs as well as a process to recycle them repeatedly.鈥�

Vitrimers are a class of polymers first developed in 2015. When exposed to certain conditions, such as heat above a specific temperature, their molecules can rearrange and form new bonds. This makes them both 鈥渉ealable鈥� (a bent PCB could be straightened, for instance) and highly recyclable.

鈥淥n a molecular level, polymers are kind of like spaghetti noodles, which wrap and get compacted,鈥� said co-senior author , a 91探花assistant professor in the mechanical engineering department. 鈥淏ut vitrimers are distinct because the molecules that make up each noodle can unlink and relink. It鈥檚 almost like each piece of spaghetti is made of small Legos.鈥�

The team鈥檚 process to create the vPCB deviated only slightly from those used for PCBs. Conventionally, semi-cured PCB layers are held in cool, dry conditions where they have a limited shelf life before they鈥檙e laminated in a heat press. Because vitrimers can form new bonds, researchers laminated fully cured vPCB layers. The researchers found that to recycle the vPCBs they could immerse the material in an organic solvent that has a relatively low boiling point. This swelled the vPCB鈥檚 plastic without damaging the glass sheets and electronic components, letting the researchers extract these for reuse.

This process allows for several paths to more sustainable, circular PCB lifecycles. Damaged circuit boards, such those with cracks or warping, can in some cases be repaired. If they aren鈥檛 repaired, they can be separated from their electronic components. Those components can then be recycled or reused, while the vitrimer and glass fibers can get recycled into new vPCBs.

The team tested its vPCB for strength and electrical properties, and found that it performed comparable to the most common PCB material (). Vashisth and co-author , a principal researcher at Microsoft Research and an affiliate assistant professor in the Allen School, are now using artificial intelligence to explore new vitrimer formulations for different uses.

Producing vPCBs wouldn鈥檛 entail major changes to manufacturing processes.

鈥淭he nice thing is that a lot of industries 鈥� such as aerospace, automotive and even electronics 鈥� already have processing set up for the sorts of two-part epoxies that we use here,鈥� said lead author , a 91探花doctoral student in the Allen School.

The team analyzed the environmental impact and found recycled vPCBs could entail a 48% reduction in global warming potential and an 81% reduction in carcinogenic emissions compared to traditional PCBs. While this work presents a technology solution, the team notes that a significant hurdle to recycling vPCBs at scale would be creating systems and incentives to gather e-waste so it can be recycled.

鈥淔or real implementation of these systems, there needs to be cost parity and strong governmental regulations in place,鈥� said Nguyen. 鈥淢oving forward, we need to design and optimize materials with sustainability metrics as a first principle.鈥�

Additional co-authors include , a 91探花postdoctoral scholar in the mechanical engineering department; , a 91探花doctoral student in the mechanical engineering department; , a senior applied scientist at Microsoft Research; , a senior researcher at Microsoft Research and an affiliate researcher in the Allen School; and , a 91探花professor in the Allen School and the electrical and computer engineering department. This research is funded by the Microsoft Climate Research Initiative, an Amazon Research Award and the Google Research Scholar Program. Zhang was supported by the 91探花Clean Energy Institute Graduate Fellowship.

For more information, contact vpcb@cs.washington.edu.

Smart accessories are increasingly common. Rings and watches track vitals, while Ray-Bans now . Wearable tech has even broached . Yet certain accessories have yet to get the smart touch.

91探花 researchers introduced the Thermal Earring, a wireless wearable that continuously monitors a user鈥檚 earlobe temperature. In a study of six users, the earring outperformed a smartwatch at sensing skin temperature during periods of rest. It also showed promise for monitoring signs of stress, eating, exercise and ovulation.

The smart earring prototype is about the size and weight of a small paperclip and has a 28-day battery life. A magnetic clip attaches one temperature sensor to a wearer鈥檚 ear, while another sensor dangles about an inch below it for estimating room temperature. The earring can be personalized with fashion designs made of resin (in the shape of a flower, for example) or with a gemstone, without negatively affecting its accuracy.

Researchers Jan. 12 in Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies. The device is not currently commercially available.

鈥淚 wear a smartwatch to track my personal health, but I鈥檝e found that a lot of people think smartwatches are unfashionable or bulky and uncomfortable,鈥� said co-lead author , a 91探花doctoral student in the Paul G. Allen School of Computer Science & Engineering. 鈥淚 also like to wear earrings, so we started thinking about what unique things we can get from the earlobe. We found that sensing the skin temperature on the lobe, instead of a hand or wrist, was much more accurate. It also gave us the option to have part of the sensor dangle to separate ambient room temperature from skin temperature.鈥�

Creating a wearable small enough to pass as an earring, yet robust enough that users would have to charge it only every few days, presented an engineering challenge.

鈥淚t鈥檚 a tricky balance,鈥� said co-lead author , who was a 91探花masters student in the electrical and computer engineering department when doing the research and is now at the University of California San Diego. 鈥淭ypically, if you want power to last longer, you should have a bigger battery. But then you sacrifice size. Making it wireless also demands more energy.鈥�

The team made the earring鈥檚 power consumption as efficient as possible, while also making space for a Bluetooth chip, a battery, two temperature sensors and an antenna. Instead of pairing it with a device, which uses more power, the earring uses Bluetooth advertising mode 鈥� the transmissions a device broadcasts to show it can be paired. After reading and sending the temperature, it goes into deep sleep to save power.

Because continuous earlobe temperature has not been studied widely, the team also explored potential applications to guide future research. In five patients with fevers, the average earlobe temperature rose 10.62 degrees Fahrenheit (5.92 degrees Celsius) compared with the temperatures of 20 healthy patients, suggesting the earring鈥檚 potential for continuous fever monitoring.

鈥淚n medicine we often monitor fevers to assess response to therapy 鈥� to see, for instance, if an antibiotic is working on an infection,鈥� said co-author , a clinical instructor at the Department of Emergency Medicine in the 91探花School of Medicine. 鈥淟onger term monitoring is a way to increase sensitivity of capturing fevers, since they can rise and fall throughout the day.鈥�

While core body temperature generally stays relatively constant outside of fever, earlobe temperature varies more, presenting several novel uses for the Thermal Earring. In small proof-of-concept tests, the earring detected temperature variations correlated with eating, exercising and experiencing stress. When tested on six users at rest, the earring鈥檚 reading varied by 0.58 F (0.32 C) on average, placing it within the range of 0.28 C to 0.56 C necessary for ovulation and period tracking; a smartwatch varied by 0.72 C.

鈥淐urrent wearables like Apple Watch and Fitbit have temperature sensors, but they provide only an average temperature for the day, and their temperature readings from wrists and hands are too noisy to track ovulation,鈥� Xue said. 鈥淪o we wanted to explore unique applications for the earring, especially applications that might be attractive to women and anyone who cares about fashion.鈥�

While researchers found several promising potential applications for the Thermal Earring, their findings were preliminary, since the focus was on the range of potential uses. They need more data to train their models for each use case and more thorough testing before the device might be used by the public. For future iterations of the device, Xue is working to integrate heart rate and activity monitoring. She鈥檚 also interested in potentially powering the device from solar or kinetic energy from the earring swaying.

鈥淓ventually, I want to develop a jewelry set for health monitoring,鈥� Xue said. 鈥淭he earrings would sense activity and health metrics such as temperature and heart rate, while a necklace might serve as an electrocardiogram monitor for more effective heart health data.鈥�

, a doctoral student in the Allen School, was a co-author on the paper. , a professor in the Allen School, and , a professor in the Allen School and the electrical and computer engineering department, were co-senior authors. This research was funded by the Washington Research Foundation and the .

For more information, contact Xue at qxue2@cs.washington.edu and Liu at yul276@ucsd.edu.

For questions specifically for Dr. Mastafa Springston, please contact Susan Gregg at sghanson@uw.edu.

Small mobile robots carrying sensors could perform tasks like catching gas leaks or tracking warehouse inventory. But moving robots demands a lot of energy, and batteries, the typical power source, limit lifetime and raise . Researchers have explored various alternatives: affixing sensors to insects, keeping charging mats nearby, or powering the robots with lasers. Each has drawbacks. Insects roam. Chargers limit range. Lasers can burn people鈥檚 eyes.

Researchers at the 91探花 have now created MilliMobile, a tiny, self-driving robot powered only by surrounding light or radio waves. Equipped with a solar panel鈥搇ike energy harvester and four wheels, MilliMobile is about the size of a penny, weighs as much as a raisin and can move about the length of a bus (30 feet, or 10 meters) in an hour even on a cloudy day. The robot can drive on surfaces such as concrete or packed soil and carry nearly three times its own weight in equipment like a camera or sensors. It uses a light sensor to move automatically toward light sources so it can run indefinitely on harvested power.

The team will present Oct. 2 at the in Madrid, Spain.

鈥淲e took inspiration from 鈥榠ntermittent computing,鈥� which breaks complex programs into small steps, so a device with very limited power can work incrementally, as energy is available,鈥� said co-lead author , a 91探花doctoral student in the Paul G. Allen School of Computer Science & Engineering. 鈥淲ith MilliMobile, we applied this concept to motion. We reduced the robot鈥檚 size and weight so it takes only a small amount of energy to move. And, similar to an animal taking steps, our robot moves in discrete increments, using small pulses of energy to turn its wheels.鈥�

The team tested MilliMobile both indoors and outdoors, in environments such as parks, an indoor hydroponic farm and an office. Even in very low light situations 鈥� for instance, powered only by the lights under a kitchen counter 鈥� the robots are still able to inch along, though much slower. Running continuously, even at that pace, opens new abilities for a swarm of robots deployed in areas where other sensors have trouble generating nuanced data.

These robots are also able to steer themselves, navigating with onboard sensors and tiny computing chips. To demonstrate this, the team programmed the robots to use their onboard light sensors to move towards a light source.

鈥溾�業nternet of Things鈥� sensors are usually fixed in specific locations,鈥� said co-lead author , a 91探花doctoral student in the Allen School. 鈥淥ur work crosses domains to create robotic sensors that can sample data at multiple points throughout a space to create a more detailed view of its environment, whether that鈥檚 a smart farm where the robots are tracking humidity and soil moisture, or a factory where they鈥檙e seeking out electromagnetic noise to find equipment malfunctions.鈥�

Researchers have outfitted MilliMobile with light, temperature and humidity sensors as well as with Bluetooth, letting it transmit data over 650 feet (200 meters). In the future, they plan to add other sensors and improve data-sharing among swarms of these robots.

, a 91探花doctoral student in the Allen School, was a co-lead author. Dennis Yin, who completed this work as 91探花undergraduate in electrical and computer engineering, and , a 91探花professor in the Allen School and in electrical and computer engineering, are co-authors, and , a 91探花assistant professor in the Allen School, is the senior author. This research was funded by an Amazon Research Award, a Google Research Scholar award, the National Science Foundation Graduate Research Fellowship Program, the National GEM Consortium, the Washington NASA Space Grant Consortium, the Pastry-Powered T(o)uring Machine Endowed Fellowship and the SPEEA ACE fellowship program.

For more information, contact millimobile@cs.washington.edu.

Researchers at the 91探花 have developed small robotic devices that can change how they move through the air by “snapping” into a folded position during their descent.

When these “microfliers” are dropped from a drone, they use a origami fold to switch from tumbling and dispersing outward through the air to dropping straight to the ground. To spread out the fliers, the researchers control the timing of each device’s transition using a few methods: an onboard pressure sensor (estimating altitude), an onboard timer or a Bluetooth signal.

Microfliers weigh about 400 milligrams 鈥� about half as heavy as a nail 鈥� and can travel the distance of a football field when dropped from 40 meters (about 131 feet) in a light breeze. Each device has an onboard battery-free actuator, a solar power-harvesting circuit and controller to trigger these shape changes in mid-air. Microfliers also have the capacity to carry onboard sensors to survey temperature, humidity and other conditions while soaring.

The team Sept. 13 in Science Robotics.

“Using origami opens up a new design space for microfliers,” said co-senior author , 91探花assistant professor in the Paul G. Allen School of Computer Science & Engineering. “We combine the Miura-ori fold, which is inspired by geometric patterns found in leaves, with power harvesting and tiny actuators to allow our fliers to mimic the flight of different leaf types in mid-air. In its unfolded flat state, our origami structure tumbles chaotically in the wind, similar to an elm leaf. But switching to the folded state changes the airflow around it and enables a stable descent, similarly to how a maple leaf falls. This highly energy efficient method allows us to have battery-free control over microflier descent, which was not possible before.”

These robotic systems overcome several design challenges. The devices:

• are stiff enough to avoid accidentally transitioning to the folded state before the signal.
• transition between states rapidly. The devices’ onboard actuators need only about 25 milliseconds to initiate the folding.
• change shape while untethered from a power source. The microfliers’ power-harvesting circuit uses sunlight to provide energy to the actuator.

The current microfliers can only transition in one direction 鈥� from the tumbling state to the falling state. This switch allows researchers to control the descent of multiple microfliers at the same time, so they disperse in different directions on their way down.

Future devices will be able to transition in both directions, the researchers said. This added functionality will allow for more precise landings in turbulent wind conditions.

Additional co-authors on this paper are and , both 91探花doctoral students in the Allen School; , a 91探花doctoral student in the mechanical engineering department; , Dennis Yin and , who completed this work as 91探花undergraduate students studying electrical and computer engineering; , 91探花professor of mechanical engineering; , 91探花assistant professor of mechanical engineering; and , 91探花professor in the Allen School.

This research was funded by a Moore Foundation fellowship, the National Science Foundation, the National GEM Consortium, the Google fellowship program, the Cadence fellowship program, the Washington NASA Space Grant fellowship Program and the SPEEA ACE fellowship program.

For more information, contact origamifliers@cs.washington.edu.

The very components that make electronics fast and easy to use also make their disposal an environmental nightmare. Components of smartphones, computers and even kitchen appliances contain heavy metals and other compounds that are toxic to us and harmful to ecosystems.

As electronics become cheaper to buy, e-waste has piled up. A 2019 from the World Economic Forum called e-waste “the fastest-growing waste stream in the world” 鈥� and for good reason. That same year, people generated more than 50 million metric tons of e-waste, the U.N.’s Global E-waste Monitor. Much of it is incinerated, piled up in landfills or exported to lower-income countries where it creates public health and environmental hazards.

Three researchers in the 91探花 College of Engineering are exploring ways to make electronics more Earth-friendly. , an assistant professor in the Paul G. Allen School of Computer Science & Engineering and researcher in the 91探花Institute for Nano-engineered Systems, will be presenting at the CHI 2022 conference in May. , an assistant professor of mechanical engineering, is indefinitely. And , an assistant professor of materials science and engineering and researcher in the Molecular Engineering & Sciences Institute, uses biological materials, such as seaweeds and other algae, to develop alternatives to plastics that can be 3D-printed.

For Earth Day, 91探花News reached out to these engineers to discuss their projects.

What features do you prioritize when designing sustainable electronics?

Vikram Iyer: There are lots of important problems to tackle in designing sustainable electronics, including reducing the environmental impact of e-waste. Our groups are trying to develop creative solutions to this problem, such as using new and more environmentally friendly materials while building functional devices that don鈥檛 compromise performance. For example, the mouse we designed with a biodegradable circuit board works when you plug it into any computer.

What was the design process like for the mouse?

VI: This project was a collaboration with , a principal researcher at Microsoft, and , a 91探花doctoral student in the Allen School. We took several steps to make this mouse:

• We optimized our circuit design to use the fewest number of silicon chips possible, because around 80% of carbon emissions associated with manufacturing electronics comes from the energy-intensive processes used to make chips.
• We use biodegradable materials when possible. For example, the circuit board that holds and connects the chips together typically contains toxic flame-retardants, but we instead pattern our circuits on a board made from flax fibers. Also, the casing for the mouse is made out of biodegradable plastics.
• We use general-purpose, programmable chips, like microcontrollers, in our designs so that we can reuse them in new devices.
• We use software to estimate the environmental impact of each stage of production to quantify the environmental impacts and identify which stages of our design to improve next.

This is just a start, and our long-term vision is to develop new materials and methods that help us generate a production cycle for electronics in which all the materials and components can either be recycled and reused, or degraded and regenerated through the natural biological cycle.

Is it really true that the mouse’s case and circuit board dissolve in water?

VI: When we submerge our circuit board in water, the fibers start to come apart and the whole thing just disintegrates. This takes about five to 10 minutes in hot water, or a few hours at room temperature. After this we鈥檙e left with the chips and circuit traces which we can filter out. We also designed two different cases, one of these can dissolve in water and the other can be commercially composted.

Would a biodegradable mouse be as durable as a conventional mouse, especially up against the body heat and moisture we produce?

VI: There are definitely sustainable methods to ensure biodegradable components are also durable. For example, you could add a thin coating of water-repellent materials to the mouse 鈥� like chitosan, which is found naturally in the outer skeleton of shellfish. We also show that we can print the case out of polylactic acid, a material commonly used to make things like commercially compostable forks. Going forward we’re really excited to partner with researchers like Eleftheria, whose group is making new sustainable materials. And by partnering closely with researchers at Microsoft, we hope to develop solutions that are scalable and deployable for industry.

What types of new materials is the Roumeli group working on?

Eleftheria Roumeli: focuses on developing materials derived from biological matter. In addition to seaweeds and other forms of algae, this includes plant residues and microbial products. Our studies aim to further our understanding of how these natural, versatile materials can be used as composite building blocks for sustainable alternatives to plastics.

How do you manufacture sustainable components 鈥� like biodegradable parts 鈥� for electronics?

ER: The great thing is that today’s manufacturing methods can be used to create sustainable components for electronics. For example, some of the biologically derived materials my group works with can be made into inks and filaments for manufacturing parts using 3D printing. We recently published a 鈥� that鈥檚 a type of blue-green algae 鈥� both with and without cellulose fibers as a filler. Cellulose is the most abundant natural polymer, and these inks are 100% compostable in soil. There鈥檚 no special composting facility required!

What are other alternative filaments you can use for 3D printing?

ER: We can also make hybrid materials that are a blend of both biological matter 鈥� such as spirulina cells 鈥� and commercial, degradable polymers. For the polymer, we use matrix materials such as polylactic acid, which Vikram mentioned before and is the most widely available industrially compostable polymer, or polybutylene adipate co-terephthalate, a soil-compostable polymer. The particular choice of components determines the properties, performance and the compostability of our filaments.

For example, for packaging, which we usually buy and “consume” very fast and then discard immediately, a material made solely of biological components would be preferable. Then, after we use it, it could be disposed of in a backyard or landfill and it would degrade in a few weeks.

But if we want a filament for the , we would need a polymer binder to ensure that the filament meets the requirements of hot-extrusion based printing.

Are there any other new innovations for sustainable electronics?

Aniruddh Vashisth: One thing we鈥檙e working on is recyclable synthetic polymers. Unlike what Eleftheria’s team studies, these polymers are not derived from biological components. Instead, these polymers consist of an adaptive network and can be recycled and reprocessed multiple times.

Unlike other plastics, these materials do not lose their thermo-mechanical properties during reprocessing and recycling. This is exciting since you can reuse the same material again and again! This phenomenon of retaining material properties is possible because the building blocks that make up these materials can detach and reattach, just like Legos.

So when we are recycling, we are disassembling and reassembling the Legos. We have been focusing on aerospace-grade composites, but we are starting to explore other applications with a wide range of target applications.

What impact would that have on the e-waste problem?

AV: Today鈥檚 e-waste is usually a complex composite, with plastics, metal and ceramic components all in the same device. Recycling these materials is a challenging task, so they often just end up in landfills and lead to pollution.

Right now there are more than 250 million computers and 7 billion phones in the world. Most of these have polymer components. Just think if the polymers used in these devices could be recycled multiple times. That would be a great step toward sustainability! Our group has been working on how to design and characterize such recycled polymer composites for a more sustainable future.

For more information, contact Iyer at vsiyer@uw.edu, Roumeli at eroumeli@uw.edu and Vashisth at vashisth@uw.edu.

Wireless sensors can monitor how temperature, humidity or other environmental conditions vary across large swaths of land, such as farms or forests.

These tools could provide unique insights for a variety of applications, including digital agriculture and monitoring climate change. One problem, however, is that it is currently time-consuming and expensive to physically place hundreds of sensors across a large area.

Inspired by how dandelions use the wind to distribute their seeds, a 91探花 team has developed a tiny sensor-carrying device that can be blown by the wind as it tumbles toward the ground. This system is about 30 times as heavy as a 1 milligram dandelion seed but can still travel up to 100 meters in a moderate breeze, about the length of a football field, from where it was released by a drone. Once on the ground, the device, which can hold at least four sensors, uses solar panels to power its onboard electronics and can share sensor data up to 60 meters away.

The team March 16 in Nature.

“We show that you can use off-the-shelf components to create tiny things. Our prototype suggests that you could use a drone to release thousands of these devices in a single drop. They’ll all be carried by the wind a little differently, and basically you can create a 1,000-device network with this one drop,” said senior author , a 91探花professor in the Paul G. Allen School of Computer Science & Engineering. “This is amazing and transformational for the field of deploying sensors, because right now it could take months to manually deploy this many sensors.”

Because the devices have electronics on board, it鈥檚 challenging to make the whole system as light as an actual dandelion seed. The first step was to develop a shape that would allow the system to take its time falling to the ground so that it could be tossed around by a breeze. The researchers tested 75 designs to determine what would lead to the smallest “terminal velocity,” or the maximum speed a device would have as it fell through the air.

“The way dandelion seed structures work is that they have a central point and these little bristles sticking out to slow down their fall. We took a 2D projection of that to create the base design for our structures,” said lead author , a 91探花assistant professor in the Allen School. “As we added weight, our bristles started to bend inwards. We added a ring structure to make it more stiff and take up more area to help slow it down.”

To keep things light, the team used solar panels instead of a heavy battery to power the electronics. The devices landed with the solar panels facing upright 95% of the time. Their shape and structure allow them to flip over and fall in a consistently upright orientation similar to a dandelion seed.

Without a battery, however, the system can’t store a charge, which means that after the sun goes down, the sensors stop working. And then when the sun comes up the next morning, the system needs a bit of energy to get started.

“The challenge is that most chips will draw slightly more power for a short time when you first turn them on,” Iyer said. “They’ll check to make sure everything is working properly before they start executing the code that you wrote. This happens when you turn on your phone or your laptop, too, but of course they have a battery.”

The team designed the electronics to include a capacitor, a device that can store some charge overnight.

“Then we’ve got this little circuit that will measure how much energy we’ve stored up and, once the sun is up and there is more energy coming in, it will trigger the rest of the system to turn on because it senses that it’s above some threshold,” Iyer said.

These devices use backscatter, a method that involves sending information by reflecting transmitted signals, to wirelessly send sensor data back to the researchers. Devices carrying sensors 鈥� measuring temperature, humidity, pressure and light 鈥� sent data until sunset when they turned off. Data collection resumed when the devices turned themselves back on the next morning.

To measure how far the devices would travel in the wind, the researchers dropped them from different heights, either by hand or by drone on campus. One trick to spread out the devices from a single drop point, the researchers said, is to vary their shapes slightly so they are carried by the breeze differently.

“This is mimicking biology, where variation is actually a feature, rather than a bug,” said co-author , a 91探花professor of biology. “Plants can’t guarantee that where they grew up this year is going to be good next year, so they have some seeds that can travel farther away to hedge their bets.”

Another benefit of the battery-free system is that there’s nothing on this device that will run out of juice 鈥� the device will keep going until it physically breaks down. One drawback to this is that electronics will be scattered across the ecosystem of interest. The researchers are studying how to make these systems more biodegradable.

“This is just the first step, which is why it’s so exciting,” Iyer said. “There are so many other directions we can take now 鈥� such as developing larger-scale deployments, creating devices that can change shape as they fall, or even adding some more mobility so that the devices can move around once they are on the ground to get closer to an area we’re curious about.”

, who completed this research as a 91探花undergraduate majoring in electrical and computer engineering and is now an engineer at Gridware, is also a co-author. This research was funded by the Moore Inventor Fellow award, the National Science Foundation and a grant from the U.S. Air Force Office of Scientific Research.

For more information, contact dandelions@cs.washington.edu.

Award numbers: #10617, FA9550-14-1-0398

White House honors 91探花engineering professor, associate dean Eve Riskin

, professor and associate dean in the 91探花College of Engineering, has been named a recipient of a 2019 Presidential Award for Excellence in Science, Mathematics and Engineering Mentoring.

The White House in science, mathematics and engineering on Aug. 3. There were 15 recipients of the mentoring award 鈥� 12 individuals and three organizations, representing 13 states and the District of Columbia.

Riskin also is a professor of electrical and computer engineering and the College of Engineering’s . She is the faculty director of the UW’s , where she works on mentoring and leadership development programs for women faculty in STEM areas.

The White House established the Presidential Award for Excellence in Science, Mathematics and Engineering Mentoring, or PAESMEM, in 1995; the award is administered by the National Science Foundation on behalf of the White House Office of Science and Technology. Each recipient receives a $10,000 award and a commemorative presidential certificate.

Previous of this award include in 2016, in 2009, in 2004, in 2003, the Women in Engineering Initiative (WIE) in 1998 and the UW-based Disabilities, Opportunities, Internetworking and Technology (DO-IT) program in 1997.

* * *
National Science Foundation renews grant for 91探花Center for Evaluation & Research for STEM Equity

The National Science Foundation has renewed a three-year grant for the , totaling $376, 535. The grant is aimed at bringing change and greater inclusion to engineering and computer science.

, a research scientist in sociology, is principal investigator on the grant with , affiliate assistant professor of sociology. Litzler directs the center and Margherio is assistant director.

The 91探花Center for Evaluation & Research for STEM Equity conducts its research in tandem with the Making Academic Change Happen team at the , in Terra Haute, Indiana, which received $243,560 from the NSF. The 91探花center works with recipients of NSF “ grants working to broaden participation in engineering, improve student outcomes and build more inclusive educational environments.

The project team is called Revolutionizing Engineering Departments Participatory Action Research, or REDPAR for short. Read a from the project that tells more about its research agenda, and a .

* * *

Kenneth Mugwanya of global health and team awarded $3 million by National Institutes of Health to study HIV prevention in Kenya

, a 91探花assistant professor of global health and public health, and his team have been awarded a five-year, $3 million grant by the National Institutes of Health.

The grant is for Mugwanya and the team to study the effectiveness of integrating methods of HIV prevention into sexual and reproductive health services for women in Kenya.

“Ensuring that young women seeking access to effective contraceptive methods in Kenya specifically, and Africa in general, are also able to protect themselves from HIV is critical for women empowerment and ending the HIV epidemic,” said Mugwanya, who is a physician-epidemiologist by training.

“Our hope is that providing family planning and HIV prevention services in a one-stop location will minimize barriers that women face in accessing HIV prevention services, including lack of time, cost and potential stigma of visiting a facility solely for HIV prevention.”

Other members of Mugwanya’s research team are , , , , and , all of the Department of Global Health, which is part of the 91探花School of Medicine and the School of Public Health.

Read more at the School of Public Health .

* * *

Doctoral student Vikram Iyer honored by Marconi Society

, a 91探花doctoral student in electrical and computer engineering, has been named one of three recipients of the by the Marconi Society.

The society is a nonprofit group named for Italian inventor and electrical engineer (1874-1937) and “celebrates, inspires and connects innovators building tomorrow’s technologies in service of a digitally inclusive world.” Iyer works in the Paul G. Allen School of Computer Science & Engineering’s .

The society’s Paul Baran Young Scholar Awards, named for a computer engineer and developer, recognize young scientists and engineers who show great capability as well as the potential to bring about digital inclusivity.

The Marconi Society honored Iyer for “creativity in developing bio-inspired and bio-integrative wireless sensor systems.” Iyer’s contributions, the society writes, “enable traditionally stationary Internet of Things devices to move, putting a new and scalable category of data collectors into the world to help us understand our environment at scale and with a fine degree of detail.”

In the movie “Ant-Man,” the title character can shrink in size and travel by soaring on the back of an insect. Now researchers at the 91探花 have developed a tiny wireless steerable camera that can also ride aboard an insect, giving everyone a chance to see an Ant-Man view of the world.

The camera, which streams video to a smartphone at 1 to 5 frames per second, sits on a mechanical arm that can pivot 60 degrees. This allows a viewer to capture a high-resolution, panoramic shot or track a moving object while expending a minimal amount of energy. To demonstrate the versatility of this system, which weighs about 250 milligrams 鈥� about one-tenth the weight of a playing card 鈥� the team mounted it on top of live beetles and insect-sized robots.

The results July 15 in Science Robotics.

“We have created a low-power, low-weight, wireless camera system that can capture a first-person view of what’s happening from an actual live insect or create vision for small robots,” said senior author , a 91探花associate professor in the Paul G. Allen School of Computer Science & Engineering. “Vision is so important for communication and for navigation, but it’s extremely challenging to do it at such a small scale. As a result, prior to our work, wireless vision has not been possible for small robots or insects.”

Typical small cameras, such as those used in smartphones, use a lot of power to capture wide-angle, high-resolution photos, and that doesn’t work at the insect scale. While the cameras themselves are lightweight, the batteries they need to support them make the overall system too big and heavy for insects 鈥� or insect-sized robots 鈥� to lug around. So the team took a lesson from biology.

“Similar to cameras, vision in animals requires a lot of power,” said co-author , a 91探花assistant professor of mechanical engineering. “It’s less of a big deal in larger creatures like humans, but flies are using 10 to 20% of their resting energy just to power their brains, most of which is devoted to visual processing. To help cut the cost, some flies have a small, high-resolution region of their compound eyes. They turn their heads to steer where they want to see with extra clarity, such as for chasing prey or a mate. This saves power over having high resolution over their entire visual field.鈥�

To mimic an animal’s vision, the researchers used a tiny, ultra-low-power black-and-white camera that can sweep across a field of view with the help of a mechanical arm. The arm moves when the team applies a high voltage, which makes the material bend and move the camera to the desired position. Unless the team applies more power, the arm stays at that angle for about a minute before relaxing back to its original position. This is similar to how people can keep their head turned in one direction for only a short period of time before returning to a more neutral position.

“One advantage to being able to move the camera is that you can get a wide-angle view of what’s happening without consuming a huge amount of power,” said co-lead author , a 91探花doctoral student in electrical and computer engineering. “We can track a moving object without having to spend the energy to move a whole robot. These images are also at a higher resolution than if we used a wide-angle lens, which would create an image with the same number of pixels divided up over a much larger area.”

The camera and arm are controlled via Bluetooth from a smartphone from a distance up to 120 meters away, just a little longer than a football field.

The researchers attached their removable system to the backs of two different types of beetles 鈥� a death-feigning beetle and a Pinacate beetle. Similar beetles have been known to be able to carry loads heavier than half a gram, the researchers said.

“We made sure the beetles could still move properly when they were carrying our system,” said co-lead author , a 91探花doctoral student in electrical and computer engineering. “They were able to navigate freely across gravel, up a slope and even climb trees.”

The beetles also lived for at least a year after the experiment ended.

“We added a small accelerometer to our system to be able to detect when the beetle moves. Then it only captures images during that time,” Iyer said. “If the camera is just continuously streaming without this accelerometer, we could record one to two hours before the battery died. With the accelerometer, we could record for six hours or more, depending on the beetle’s activity level.”

The researchers also used their camera system to design the world鈥檚 smallest terrestrial, power-autonomous robot with wireless vision. This insect-sized robot uses vibrations to move and consumes almost the same power as low-power Bluetooth radios need to operate.

The team found, however, that the vibrations shook the camera and produced distorted images. The researchers solved this issue by having the robot stop momentarily, take a picture and then resume its journey. With this strategy, the system was still able to move about 2 to 3 centimeters per second 鈥� faster than any other tiny robot that uses vibrations to move 鈥� and had a battery life of about 90 minutes.

While the team is excited about the potential for lightweight and low-power mobile cameras, the researchers acknowledge that this technology comes with a new set of privacy risks.

“As researchers we strongly believe that it’s really important to put things in the public domain so people are aware of the risks and so people can start coming up with solutions to address them,” Gollakota said.

Applications could range from biology to exploring novel environments, the researchers said. The team hopes that future versions of the camera will require even less power and be battery free, potentially solar-powered.

“This is the first time that we’ve had a first-person view from the back of a beetle while it’s walking around. There are so many questions you could explore, such as how does the beetle respond to different stimuli that it sees in the environment?” Iyer said. “But also, insects can traverse rocky environments, which is really challenging for robots to do at this scale. So this system can also help us out by letting us see or collect samples from hard-to-navigate spaces.”

, a 91探花mechanical engineering doctoral student, is also a co-author on this paper. This research was funded by a Microsoft fellowship and the National Science Foundation.

For more information, contact insectcam@cs.washington.edu.

Farmers can already use drones to soar over huge fields and monitor temperature, humidity or crop health. But these machines need so much power to fly that they can’t get very far without needing a charge.

Now, engineers at the 91探花 have created a sensing system that is small enough to ride aboard a bumblebee. Because insects can fly on their own, the package requires only a tiny rechargeable battery that could last for seven hours of flight and then charge while the bees are in their hive at night. The research team will聽 Dec. 11 and in person at the .

“Drones can fly for maybe 10 or 20 minutes before they need to charge again, whereas our bees can collect data for hours,” said senior author , an associate professor in the UW’s Paul G. Allen School of Computer Science & Engineering. “We showed for the first time that it’s possible to actually do all this computation and sensing using insects in lieu of drones.”

While using insects instead of drones solves the power problem, this technique has its own set of complications: First, insects can’t carry much weight. And second, GPS receivers, which work well for helping drones report their positions, consume too much power for this application. To develop a sensor package that could fit on an insect and sense its location, the team had to address both issues.

“We decided to use bumblebees because they’re large enough to carry a tiny battery that can power our system, and they return to a hive every night where we could wirelessly recharge the batteries,” said co-author , a doctoral student in the 91探花Department of Electrical & Computer Engineering. “For this research we followed the best methods for care and handling of these creatures.”

Previously other research groups have by supergluing small trackers, like radio-frequency identification, or RFID, tags, to them to follow their movement. For these types of experiments, researchers put a bee in the freezer for a few minutes to slow it down before they glue on the backpack. When they’re finished with the experiment, the team removes the backpack through a similar process.

These prior studies, however, only involved backpacks that simply tracked bees’ locations over short distances 鈥� around 10 inches 鈥� and did not carry anything to survey the environment around the insects. Here, Gollakota, Iyer and their group designed a sensor backpack that rides on the bees’ backs and weighs 102 milligrams, or about the weight of .

“The rechargeable battery powering the backpack weighs about 70 milligrams, so we had a little over 30 milligrams left for everything else, like the sensors and the localization system to track the insect’s position,” said co-author , a doctoral student in the Allen School.

Because bees don’t advertise where they are flying and because GPS receivers are too power-hungry to ride on a tiny insect, the team came up with a method that uses no power to localize the bees. The researchers set up multiple antennas that broadcasted signals from a base station across a specific area. A receiver in a bee’s backpack uses the strength of the signal and the angle difference between the bee and the base station to triangulate the insect’s position.

“To test the localization system, we did an experiment on a soccer field,” said co-author , a doctoral student in the Allen School. “We set up our base station with four antennas on one side of the field, and then we had a bee with a backpack flying around in a jar that we moved away from the antennas. We were able to detect the bee’s position as long as it was within 80 meters, about three-quarters the length of a football field, of the antennas.”

Next the team added a series of small sensors 鈥� monitoring temperature, humidity and light intensity 鈥� to the backpack. That way, the bees could collect data and log that information along with their location, and eventually compile information about a whole farm.

“It would be interesting to see if the bees prefer one region of the farm and visit other areas less often,” said co-author , an assistant professor in the 91探花Department of Mechanical Engineering. “Alternatively, if you want to know what’s happening in a particular area, you could also program the backpack to say: ‘Hey bees, if you visit this location, take a temperature reading.'”

Then after the bees have finished their day of foraging, they return to their hive where the backpack can upload any data it collected via a method called , through which a device can share information by reflecting radio waves transmitted from a nearby antenna.

Right now the backpacks can only store about 30 kilobytes of data, so they are limited to carrying sensors that create small amounts of data. Also, the backpacks can upload data only when the bees return to the hive. The team would eventually like to develop backpacks with cameras that can livestream information about plant health back to farmers.

“Having insects carry these sensor systems could be beneficial for farms because bees can sense things that electronic objects, like drones, cannot,” Gollakota said. “With a drone, you’re just flying around randomly, while a bee is going to be drawn to specific things, like the plants it prefers to pollinate. And on top of learning about the environment, you can also learn a lot about how the bees behave.”

###

For more information, contact the research team at livingiot@cs.washington.edu.