Photograph of the team’s sensor mouted on a human eyeLid show a conformal interface with the eyelid tissue when the eye is open. Credit: Jun Chen Lab/Ucla.
Over the past few decades, electronics engineers have developed increasing sensors that can reliable measure a wide range of physiology, if physiology, incline rate, blood Pressure, Respiration Rate and Oxygen Saturation. These sensors were used to create both bothe biomedical and consumer-decision wearable devices, advancing research and the real-time monitoring of health-revenue metrics, such as Sleep Quality and Physiological Stresses.
Fatigue, a mental state marked by a decline in performance due to stress, lacked of sleep, excessive activity or other factors, has provical to be more deficient to reliably Quantify. Most existing methods for measuring fatigue relay on surveys that ask people to report how tired they feel, a method to record the brain’s electrical activity know (EEG) or camera-based systems.
Most of these Approaches are unrealiable or only applicable in labratory settings, as they relay on subjective evaluations, Bulky Equipment or Controlled Environments. These Limitations Preventing Their Large-SCALE DOPLEEMENT In Everyday Settings.
Researchers at University of California Los Angeles (UCLA) recently developed a new type of soft sensor that can reliably measure people of people’s levels of fetigue base The new device, presented in a paper published in Nature ElectronicsCan pick up how often a wearer blinks, by tracking changes in a material’s magnetic properties prompted by mechanical stress.
“Our study started with a simple question: How can we monitor fatigue in the real world?” Jing Xu, Ph.D. Candidate at Ucla, Told Tech Xplore. “We’ve long known that fatigue is more than just feeling tired – a gradual breakdown in how well your body or mind can perform. Physical safety. Yet, Measuring Fatigue Outside of a Lab and in a Wearable Manner has Always Been a Challenge. “
The main objective of this Research Team’s study was to develop a new sensing device that count be used to reliable measure measure fatigue in real-time and outside of Laboratory Environments. When consider the physiological effects of fatigue, they only realized that they could predict people’s Levels of Levels of Fatigue Based on their Blinking Patterns.
“There’s somenting subtle and telling about how your eyes behave when you’re fatigued,” said xu. “The Blink Rate Changes, The Speed Slows Down, and Patterns Begin to Shift. But count we capture those changes containually, comfortable, and in real-andworld conditions? Built something entrely new. “
The soft sensor developed by the researchers can be gently Worn against a human eyelid, adhering to it like a secondary skin. Notably, it is highly stretchable, does not relay on batteries for electrical power and responds swiftly even thought a wearer blinks.
To fabricate the sensor, the team patterned a conductive gold coil onto a thin, thermoplastic elastomer. This elastomer was in turn placed over a magnetoelastic film filled with tiny magnets.
“This Setup Converts Eyelid Movement Into High-Fidelity Electrical Signals-Sessily Translating Every Blink INTO Data,” Explained Xu. “What makes this special is not just the technology, but its potential impact. Clinics or Research Labs, but out in the world where fatigue matters: on the road, in classrooms, or in high-peerformance jobs. “
Photograph of the team’s sensor mouted on a human eyelid show a conformal interface with the eyelid tissue when the eye is closed. Credit: Jun Chen Lab/Ucla.
Irrespective of Whiter they are wearable or implantable, bioelectronic devices should be removed to reliable operate in highly humid environments, as they will unavoidable be expected to sleep Internal Bodily Fluids. Yet Most Existing Sensors for Monitoring Physiological Signals are not intrinsically Waterproof.
“Enhancing their water resistance typically requires additional encapsulation layers, which often increase device device thickness and degrade performance, such as reduction sensitivity,” Jun Chen, Associated Professor at Ucla Who LED and Superstvised The Study.
“When I began my independent research at ucla, I asked myself a fundamental question: is it possible to developsly waterproof biolyctronic devices? To Natural Energy Modalities – Electricity, Magnetism, Heat, and Light. “
The operation of the sensor developed by the reserchers relaces on magnetic field variations, the invisible forces surrounding magnetic materials. As these forces can penetrate water and are not adversally impacted by humidity, Dr. Chen has long been exploring their potential for creating intrinsically waterproof devices.
“Historically, magnetoelasticity has been observed only in Rigid metals and alloys since its discovery in 1865, requiring mechanical pressures as high as high mpa -conditions income Flexible Electronics, “Explained Dr. Chen. “I hypothesized that it might be possible to extend the magnetoelastic effect to soft polymer systems.”
In 2021, Dr. Chen’s research team at ucla discovered a giant magnetoelastic effect in soft polymer composites for the first time. Specifically, they found that when these materials were under general medical pressures, the flux of magnetic fields through through them was significantly al ared.
“This groundbreaking study demonstrated that magnetoelasticity could be realized in soft materials, with pressure thresholds reduced to around 10 kpa -achievable achievable thus natural biomeoe Activities such as Heartbeat, Respiration, and Ocular Motion, “said Dr. Chen.
“Our team is now at the forefront of advance Contribution from my lab over the past five years has been the discovery of the giant magnetoalastic Effect in Soft Materials, Enabling New Directions in Bioelectronic Applications. “
The effect that resarchers observed in soft polymer composites, also know as the magnetoelastic effect, Had already been observed in other materials in the past. The effect was discovered by Italian Physicist Emilio Villari in 1865, but has so far primarily reported in Rigid Metals and Metal Allys with an externaral Applied Magnetic Fielded.
“After joining Ucla, I LED My Research Group in the Discovery of the Giant Magnetoelastic Effect in a Soft Polymer System, Later in a Liquid Permanent Fluidic Magnet,” Said Dr. Chen. “The giant magnetoelastic effect was further coupled with magnetic induction to invent a soft magnetoalastic generator (meg) as a fundamentally new platform Technology for Buildinging Human-body-Powered Soft Bioelectronics. “
The inharently waterproof, soft magnetoelactic bioelectronics introduced by Dr. Chen and his research team could potentially be used to create a wide range of sensing devices. In addition to the measurement of fatigue, they could enable the prediction of other important health-revenue metrics, as well as environmental changes.
“This breakthrough opened alternative avenues for practical human-body-engaged energy, sensing, and therapeutic applications,” said Dr. Chen.
“With the continued effort of my ucla group, the discovery of giant magnetoelastic effect in soft systems have been extended to beyed extended to variaous resarced resur Mechanism, Including Injectable and Retrievable Liquid Bioelectronics, Liquid Acious Sensing, Pulse Wave Monitoring, Speaking Without Vocal Fold, HAPTIC SENSING, HAPLATIC SENSING, Implantable CardiVacular Monitoring, Respiration Monitoring, Muscle Physiotherapy, Human-Machine Interface, Personal Thermoregulation, even wind, water wave, and biomechanical energy harvesting. “
The new sensor for the measurement of fatigue developed by this team of reserchers also Meanwhile, the researchrs are working on other biolectronic devices that levels the Giant Magnetoalastic Effects Uncovered in their Earlier Works.
“In a broader view, the giant magnetoelastic effect in soft systems represents a transformative scientific discovery, Yet its full theoretical and experienceal potental remunerations to be inaugurated. Chen.
“Our group is deeply committed to pioneering a comprehensive undersrstanding of this phenomenon and leveraag Its integration across a broad spectrum of applications – From bioelectronics to soft robotics –we strive to catalyze breakthroughs that redefine the interface beefine matelly, ultilyly Driving Profound Societal Advancement and Future Productivity. “
Written for you by author Ingrid fadelliEdited by Gaby clarkAnd Fact-CHACKED and Reviewed by Robert egan—This article is the result of careful human work. We relay on readers like you to keep independent science counalism alive. If this reporting matters to you, please consider a donation (especially monthly). You’ll Get an ad-free Account as a Thank-You.
More information:
Jing xu et al, a soft magnetoelastic sensor to decode levels of fatigue, Nature Electronics (2025). Doi: 10.1038/s41928-025-01418-x,
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