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Image of Kelsi Rutledge

The nature of innovation

Marine scientist Kelsi Rutledge explores new possibilities for bioinspired design

Image of Kelsi Rutledge on a beach in a lab coat, holding a preserved museum specimen of ray.

© Jade Nelson
UC Grad Slam finalist Kelsi Rutledge holds a preserved museum specimen of Pseudobatos buthi, a new ray species she discovered.

Lucy Berbeo

Kelsi Rutledge wants you to understand the world from a fish’s perspective — a stingray’s, to be exact — and for good reason: this fascinating creature and its relatives may help lead the way to a more sustainable future.

Swimming the seas since prehistoric times, the ray is famed for its flat body, wing-like fins and venomous barb. But it has something else that the casual observer can’t see: a curiously shaped, powerful nose that can track a scent like a bloodhound. Rutledge, a doctoral student in the UCLA Department of Ecology and Evolutionary Biology, is shedding new light on this sensory superpower and what we can learn from it.

“There are all kinds of rays — huge, pelagic manta rays, deep-sea thorny skates, blind electric rays — and they all have different types of noses,” she says. “Some are circular, some are slit-like, others protrude from their heads. Why do they look so different, and how do they work? It’s not a simple question to answer. Unlike humans, their noses aren’t involved in breathing; they evolved only for smell. Without a pump-like system to bring odors in, how do their noses still smell so efficiently?”

Rooted in these questions, Rutledge’s research earned her a spot as a finalist in this year’s statewide UC Grad Slam competition. She’s interested in how the rays’ sniffers may influence bioinspired design, where technical innovations take a cue from nature’s systems and processes. Her findings are already being used by U.S. Navy engineers to improve underwater technology.

Image of a ray underwater, photographed from below with the nose visible.

David Clode/Unsplash

Rutledge’s research journey started at L.A.’s Natural History Museum — where, she says, scientists can check out animals “like books.” After borrowing a number of ray specimens, she worked with staff at UCLA Radiology to CT-scan the fishes’ heads, including their noses of varying shapes and sizes, then used a 3D printer to construct anatomically accurate models. Back at the lab, she used powerful lasers to illuminate water movement and compare the noses in action.

“We tracked individual water parcels to find out how the different nose shapes harnessed odors, which was fastest and most effective, and then tied that back to their ecology,” she says. “We wanted to understand why they evolved this system: do some species rely on sense of smell more than others? For example, deep-sea fishes with limited vision might need an odor-harnessing system that’s quicker and more efficient.”


“Through thousands of years of evolution, nature often provides innovative solutions to complex problems. If we can try to mimic what animals do so elegantly, we have the opportunity to advance our own technology.”


Learning to imitate the rays’ evolutionary “design” may be a game-changer in the era of climate change. Odors are chemicals, and monitoring chemical content in the ocean is vital in tracking the health of our seas, which provide nearly three-quarters of our oxygen. Chemicals like phosphorous, silicate and nitrogen also form the basis of the ocean’s food web, giving nutrients to phytoplankton and algae. And while current chemical detection methods are expensive and tech-heavy, the form and function of ray noses may inspire simple, energy-conscious solutions.

“There’s so much we can learn from animals. I have another paper that looked at the crushing power of stingray jaws — they can actually crush material that’s harder than their own skeleton,” Rutledge says. “Through thousands of years of evolution, nature often provides innovative solutions to complex problems. If we can try to mimic what animals do so elegantly, we have the opportunity to advance our own technology.”

Rutledge has long been curious about nature’s hidden, yet complex and fascinating worlds. Growing up in the mountains of North Carolina, she was drawn to ocean life and to the study of fishes in particular because of their incredible biodiversity, which led her down endless “research rabbit holes.” As a master’s student, she discovered a new species of guitarfish, a lesser-known and threatened ray relative. The news was covered by Forbes, Smithsonian Magazine and more — hardly typical in the old-school world of taxonomy.

Image of Kelsi Rutledge in a red dress on the beach, holding a preserved museum specimen of ray.

© Jade Nelson
Rutledge named the new species Pseudobatos buthi in honor of her supportive graduate advisor at UCLA, the late Don Buth.

“I staged a photoshoot with my professional photographer friend where I took silly photos with one of the museum specimens of my new species, similar in style to a birth announcement,” she shared on her website. “With a bit of apprehension, I then took to Twitter to post the photos. My hope was to engage scientists and non-scientists alike and highlight the importance of museum collections and this understudied and endangered group of fishes.”

After graduating this year, Rutledge will go on to Caltech’s Dabiri Lab to shine the spotlight on another odd but fascinating creature, the jellyfish — which, like the stingray, has managed to outlive the dinosaurs. “I’m really excited about this new project. Jellyfish are one of the most efficient swimmers in the ocean,” she says. “They’re so simple and complex at the same time.”

And in a field with endless possibilities, Rutledge continues to find wonder and inspiration in fishes, our strange evolutionary ancestors. “There’s so much we can learn about them,” she says. “There’s still so much to be discovered.”

Learn more about Kelsi Rutledge’s research and teaching at her website, fishandfreckles.com.


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Sweating the small stuff: Smartwatch developed at UCLA measures key stress hormone

Image of smartwatch developed at UCLA that assesses cortisol levels found in sweat

Cortisol is well-suited for measurement through wearable devices, according to study co-author Sam Emaminejad, because its concentration levels in sweat are similar to its circulating levels. Photo credit: Yichao Zhao and Zhaoqing Wang/UCLA

Editor’s note: This breakthrough by UCLA College researchers was featured on BBC Click, the BBC’s flagship tech show. Click here to watch the clip at the BBC website.

By Wayne Lewis

The human body responds to stress, from the everyday to the extreme, by producing a hormone called cortisol.

To date, it has been impractical to measure cortisol as a way to potentially identify conditions such as depression and post-traumatic stress, in which levels of the hormone are elevated. Cortisol levels traditionally have been evaluated through blood samples by professional labs, and while those measurements can be useful for diagnosing certain diseases, they fail to capture changes in cortisol levels over time.

Now, a UCLA research team has developed a device that could be a major step forward: a smartwatch that assesses cortisol levels found in sweat — accurately, noninvasively and in real time. Described in a study published in Science Advances, the technology could offer wearers the ability to read and react to an essential biochemical indicator of stress.

“I anticipate that the ability to monitor variations in cortisol closely across time will be very instructive for people with psychiatric disorders,” said co-corresponding author Anne Andrews, a UCLA professor of psychiatry and biobehavioral sciences, member of the California NanoSystems Institute at UCLA and member of the Semel Institute for Neuroscience and Human Behavior. “They may be able to see something coming or monitor changes in their own personal patterns.”

Cortisol is well-suited for measurement through sweat, according to co-corresponding author Sam Emaminejad, an associate professor of electrical and computer engineering at the UCLA Samueli School of Engineering, and a member of CNSI.

“We determined that by tracking cortisol in sweat, we would be able to monitor such changes in a wearable format, as we have shown before for other small molecules such as metabolites and pharmaceuticals,” he said. “Because of its small molecular size, cortisol diffuses in sweat with concentration levels that closely reflect its circulating levels.”

► Related: UCLA-led team develops new system for tracking chemicals in the brain

The technology capitalizes on previous advances in wearable bioelectronics and biosensing transistors made by Emaminejad, Andrews and their research teams.

Illustration of the components of the smartwatch and how it sits atop the skin.

The technology capitalizes on previous work by Sam Emaminejad, Anne Andrews and their UCLA research teams. Image credit: Emaminejad Lab and Andrews Lab/UCLA

In the new smartwatch, a strip of specialized thin adhesive film collects tiny volumes of sweat, measurable in millionths of a liter. An attached sensor detects cortisol using engineered strands of DNA, called aptamers, which are designed so that a cortisol molecule will fit into each aptamer like a key fits a lock. When cortisol attaches, the aptamer changes shape in a way that alters electric fields at the surface of a transistor.

The invention — along with a 2021 study that demonstrated the ability to measure key chemicals in the brain using probes — is the culmination of a long scientific quest for Andrews. Over more than 20 years, she has spearheaded efforts to monitor molecules such as serotonin, a chemical messenger in the brain tied to mood regulation, in living things, despite transistors’ vulnerability to wet, salty biological environments.

In 1999, she proposed using nucleic acids — rather than proteins, the standard mechanism — to recognize specific molecules.

“That strategy led us to crack a fundamental physics problem: how to make transistors work for electronic measurements in biological fluids,” said Andrews, who is also a professor of chemistry and biochemistry.

Meanwhile, Emaminejad has had a vision of ubiquitous personal health monitoring. His lab is pioneering wearable devices with biosensors that track the levels of certain molecules that are related to specific health measures.

“We’re entering the era of point-of-person monitoring, where instead of going to a doctor to get checked out, the doctor is basically always with us,” he said. “The data are collected, analyzed and provided right on the body, giving us real-time feedback to improve our health and well-being.”

Emaminejad’s lab had previously demonstrated that a disposable version of the specialized adhesive film enables smartwatches to analyze chemicals from sweat, as well as a technology that prompts small amounts of sweat even when the wearer is still. Earlier studies showed that sensors developed by Emaminejad’s group could be useful for diagnosing diseases such as cystic fibrosis and for personalizing drug dosages.

► Related: Adhesive film turns smartwatch into biochemical health monitoring system

One challenge in using cortisol levels to diagnose depression and other disorders is that levels of the hormone can vary widely from person to person — so doctors can’t learn very much from any single measurement. But the authors foresee that tracking individual cortisol levels over time using the smartwatch may alert wearers, and their physicians, to changes that could be clinically significant for diagnosis or monitoring the effects of treatment.

Among the study’s other authors is Janet Tomiyama, a UCLA associate professor of psychology, who has collaborated with Emaminejad’s lab over the years to test his wearable devices in clinical settings.

“This work turned into an important paper by drawing together disparate parts of UCLA,” said Paul Weiss, a UCLA distinguished professor of chemistry and biochemistry and of materials science and engineering, a member of CNSI, and a co-author of the paper. “It comes from us being close in proximity, not having ego problems and being excited about working together. We can solve each other’s problems and take this technology in new directions.”

The latest research builds upon early work that was funded by the National Science Foundation and the National Institutes of Health. The current study received funding from the NSF CAREER program, the National Institute on Drug Abuse through an NIH Director’s Transformative Research Award, the National Institute of General Medical Science of the NIH, the Henry M. Jackson Foundation, the Stanford Genome Technology Center, the Brain and Behavior Foundation and the PhRMA Foundation.

The UCLA NanoLab, Electron Imaging Center for NanoMachines and Nano and Pico Characterization Laboratory, all housed at CNSI, provided instrumentation for the new study.

The paper’s co-first authors are UCLA postdoctoral scholar Bo Wang and Chuanzhen Zhao, a former UCLA graduate student. Other co-authors are Zhaoqing Wang, Xuanbing Cheng, Wenfei Liu, Wenzhuo Yu, Shuyu Lin, Yichao Zhao, Kevin Cheung and Haisong Lin, all of UCLA; and Milan Stojanović and Kyung-Ae Yang of Columbia University.

This article originally appeared in the UCLA NewsroomFor more news and updates from the UCLA College, visit college.ucla.edu.

Best in snow: New scientific device creates electricity from snowfall

UCLA researchers and colleagues have designed a new device that creates electricity from falling snow. The first of its kind, this device is inexpensive, small, thin and flexible like a sheet of plastic.

“The device can work in remote areas because it provides its own power and does not need batteries,” said senior author Richard Kaner, who holds UCLA’s Dr. Myung Ki Hong Endowed Chair in Materials Innovation. “It’s a very clever device — a weather station that can tell you how much snow is falling, the direction the snow is falling, and the direction and speed of the wind.”

The researchers call it a snow-based triboelectric nanogenerator, or snow TENG. A triboelectric nanogenerator, which generates charge through static electricity, produces energy from the exchange of electrons.

Findings about the device are published in the journal Nano Energy.

Maher El-Kady and Richard Kaner

Maher El-Kady and Richard Kaner

“Static electricity occurs from the interaction of one material that captures electrons and another that gives up electrons,” said Kaner, who is also a distinguished professor of chemistry and biochemistry, and of materials science and engineering, and a member of the California NanoSystems Institute at UCLA. “You separate the charges and create electricity out of essentially nothing.”

Snow is positively charged and gives up electrons. Silicone — a synthetic rubber-like material that is composed of silicon atoms and oxygen atoms, combined with carbon, hydrogen and other elements — is negatively charged. When falling snow contacts the surface of silicone, that produces a charge that the device captures, creating electricity.

“Snow is already charged, so we thought, why not bring another material with the opposite charge and extract the charge to create electricity?” said co-author Maher El-Kady, a UCLA assistant researcher of chemistry and biochemistry.

“While snow likes to give up electrons, the performance of the device depends on the efficiency of the other material at extracting these electrons,” he added. “After testing a large number of materials including aluminum foils and Teflon, we found that silicone produces more charge than any other material.”

About 30 percent of the Earth’s surface is covered by snow each winter, during which time solar panels often fail to operate, El-Kady noted. The accumulation of snow reduces the amount of sunlight that reaches the solar array, limiting the panels’ power output and rendering them less effective. The new device could be integrated into solar panels to provide a continuous power supply when it snows, he said.

Hiking shoe with device attached

Hiking shoe with device attached

The device can be used for monitoring winter sports, such as skiing, to more precisely assess and improve an athlete’s performance when running, walking or jumping, Kaner said. It also has the potential for identifying the main movement patterns used in cross-country skiing, which cannot be detected with a smart watch.

It could usher in a new generation of self-powered wearable devices for tracking athletes and their performances.

It can also send signals, indicating whether a person is moving. It can tell when a person is walking, running, jumping or marching.

The research team used 3-D printing to design the device, which has a layer of silicone and an electrode to capture the charge. The team believes the device could be produced at low cost given “the ease of fabrication and the availability of silicone,” Kaner said. Silicone is widely used in industry, in products such as lubricants, electrical wire insulation and biomedical implants, and it now has the potential for energy harvesting.

Co-authors include Abdelsalam Ahmed, who conducted the research while completing his doctoral studies at the University of Toronto; Islam Hassan and Ravi Selvaganapathy of Canada’s McMaster University; and James Rusling of the University of Connecticut and his research team.

Kaner’s research was funded by Nanotech Energy, a company spun off from his research (Kaner is chair of its scientific advisory board and El-Kady is chief technology officer); and Kaner’s Dr. Myung Ki Hong Endowed Chair in Materials Innovation.

Kaner’s laboratory has produced numerous devices, including a membrane that separates oil from water and cleans up the debris left by oil fracking. Fracking is a technique to extract gas and oil from shale rock.

Kaner, El-Kady and colleagues designed a device in 2017 that can use solar energy to inexpensively and efficiently create and store energy, which could be used to power electronic devices and to create hydrogen fuel for eco-friendly cars. This year, they published research on their design of the first fire-retardant, self-extinguishing motion sensor and power generator, which could be embedded in shoes or clothing worn by firefighters and others who work in harsh environments.

Kaner is among the world’s most influential and highly cited scientific researchers. He was selected as the recipient of the American Institute of Chemists 2019 Chemical Pioneer Award, which honors chemists and chemical engineers who have made outstanding contributions that advance the science of chemistry or greatly impact the chemical profession.