- Home
- About Us
- Contact Us
- Biography
- Column
- MedBound Hub
- InternshipInternship
- Daily Pulse
- Medicine
- Physical Therapy
- InterviewInterview
- Pharmacy
- Biotechnology
- College/InstituteCollege/Institute
- Dentistry
- Blog
- Wellness & Nutrition
- Nursing
- Opinion
Penn State researchers and international collaborators developed a soft, stretchable antenna that can keep working even when pulled in different directions. This new stretchable antenna could help wearable health monitors maintain reliable wireless connections as the body bends, stretches and moves during everyday activities.
The medical application is the top priority for us, because we see the great potential for this in monitoring human health.
Huanyu “Larry” Cheng, the James L. Henderson Jr. Memorial Professor of Engineering Science and Mechanics at Penn State and a corresponding author of the study.
The antenna is designed for radiofrequency, or RF, communication, the broad category of wireless technology behind Bluetooth, Wi-Fi and a variety of sensors including health monitors. Antennas not only transmit information through this wireless technology, but they can also harvest energy via RF to power a sensor or other parts of a monitoring system. Unlike a conventional rigid antenna, the new design can stretch with fabric or skin-like materials while staying close to the frequency it needs to send or receive signals or power.
In tests, the antenna remained stable even when stretched up to 45% in multiple directions. Stretching usually changes the frequency an antenna is tuned to, much like knocking a radio dial and losing the station. The new design kept that change small enough that the antenna continued working reliably.
For Cheng, the work addresses a basic challenge in wearable electronics: Sensors may be stretchable, but their antennas often are not.
When you stretch a sensor, as long as you don’t break the sensor, it still works, but for an antenna, you actually change the resonance frequency because of the way antennas and RF work. Stretching makes the antenna longer, and the resonance frequency becomes smaller.
Huanyu “Larry” Cheng, the James L. Henderson Jr. Memorial Professor of Engineering Science and Mechanics at Penn State and a corresponding author of the study.
That shift matters for wearable devices that rely on steady wireless communication. The researchers’ solution was to rethink the shape of the antenna. They built it from tiny liquid metal particles embedded in Ecoflex, a soft, rubber-like material designed to stretch without breaking. They also added a cross-shaped opening in the center of the circular antenna, a key design feature that helps keep wireless signals stable even as the antenna changes shape. When the antenna stretches, the signal path inside the antenna does not simply become longer or shorter. Instead, the slot helps guide that path around the opening, allowing the antenna to compensate for changes in shape.
If you have a simple circular hole, the antenna can work when it’s stretched in any direction but you’re losing conductive material, which reduces the antenna’s efficiency, a single slot would preserve more material, but it would only help when the antenna is stretched in certain directions. We had to strike a balance to achieve the best overall performance, which we did with the cross shape.
Senhao Zhang, Engineering science and mechanics doctoral candidate and co-corresponding author.
To show that the antenna could work as part of a practical system, including to harvest energy, the researchers tested it in two demonstrations. In one demonstration, the researchers showed that the antenna could harvest energy from radio waves and convert it into enough electricity to power a small LED light even while the antenna was stretched by about 30% in different directions. A conventional stretchable antenna, by comparison, lost its ability to provide stable power after being stretched by only about 5%.
In a second demonstration, the researchers used a related version of the antenna for wireless health monitoring. They mounted it on a smart T-shirt with electrocardiogram, or ECG, electrodes and connected it to a Bluetooth Low Energy monitoring system.
The system transmitted stable ECG signals from distances ranging from about 6 feet to more than 300 feet, even after the antenna was stretched. Based on these results, Cheng said, the most immediate benefits are likely in healthcare. A stretchable antenna that can keep communicating during motion could help wearable monitors track health information more continuously and reliably during daily life, exercise or rehabilitation.
Practical application will require the actual use of the antenna in the sensing and integration of the system, here, the demonstration shows we can get this integrated so the energy can be harvested, and the data can be transmitted.
Huanyu “Larry” Cheng, the James L. Henderson Jr. Memorial Professor of Engineering Science and Mechanics at Penn State and a corresponding author of the study.
Based on these results, Cheng said, the most immediate benefits are likely in healthcare. A stretchable antenna that can keep communicating during motion could help wearable monitors track health information more continuously and reliably during daily life, exercise or rehabilitation. Looking further ahead, Zhang said similar soft RF systems could be useful beyond human wearables, including in flying robots or environmental monitoring systems.
We’d be very excited to apply this technology to flying robots that could monitor changes in the environment, such as temperature and other environmental conditions, that could help us better understand how pollinators like bees and other species are responding to a changing environment.
Senhao Zhang, visiting scholar, engineering science and mechanics doctoral candidate and co-corresponding author
The broader goal is not simply to make an antenna stretch, Cheng said. It is to help wearable electronics keep communicating when people move naturally, which can be the moments when continuous monitoring may matter most.
The contributions made to this project by Penn State researchers were supported by the National Institutes of Health's (NIH) National Institute of Biomedical Imaging and Bioengineering under award number R21EB030140 and the U.S. National Science Foundation under award numbers 2309323 and 2319139. This content is solely the responsibility of the authors and does not necessarily represent the views of the NIH or NSF.
Reference:
Yang, Furong, Senhao Zhang, Jinyao Zhang, Yao Tong, Jun Zhong, Junjie Zheng, Jiawei Li, Yichao Hu, Yangbo Yuan, Jia Zhu, Kai Xu, Cheng Zhang, Huanyu Cheng, and Chaoyun Song. “Multidirectional Strain-Insensitive Stretchable RF Electronics.” Nature Communications 17 (2026): 8041.
https://www.nature.com/articles/s41467-026-74900-5
(Newswise/AM)
