University of Missouri researchers develop ultrasoft material for on-skin health devices

Zheng Yan and colleagues from the University of Missouri have designed a soft, pliable material that can barely be felt on a person’s skin, allowing for optimal long-term health monitoring through wearable bioelectronics.

The innovative material, which is both breathable and stretchable, paves the way for the development of an on-skin, wearable device that is designed to monitor multiple vital signs simultaneously. 

Team members have set a goal to improve the long-term biocompatibility and the accuracy of wearable bioelectronics through the use of this porous material, the university said in a release. 

Yan, an assistant professor in the Department of Chemical and Biomedical Engineering and the Department of Mechanical and Aerospace Engineering, said the material's softness is a key feature. When the device is worn on the human body, it is mechanically imperceptible, ensuring a high level of user comfort. 

The material exerts less pressure than the 20 kilopascals typically felt when something is stretched on the skin. The ultrasoft material boasts additional benefits, such as integrated antibacterial and antiviral properties, which help prevent the formation of harmful pathogens on the skin, underneath the device, during extended use. 

Yan described the "mechanical and electrical decoupling," where the material's stretchability has minimal impact on the device's electrical performance during human motion, enabling the recording of high-quality biological signals.

Team members, along with Yan, are not the first researchers to have explored liquid-metal elastomer composites. However, what sets them apart is their use of a unique breathable "porous" material, the university said in its article. This design prevents the liquid metal from leaking out when the material is stretched as the body moves. 

The team's research builds upon its previous work, which includes the development of a heart monitor currently in progress. Yan envisions the collected biological data being wirelessly transmitted to smartphones or similar devices for sharing with medical professionals.

In the team’s study, titled "Porous liquid metal–elastomer composites with high leakage resistance and antimicrobial property for skin-interfaced bioelectronics," was published in Science Advances, a journal of the American Association for the Advancement of Science (AAAS). 

Co-authors of the study include: Yadong Xu, Yajuan Su, Xianchen Xu, Brian Arends, Ganggang Zhao, Daniel Ackerman, Henry Huang, St. Patrick Reid, Joshua Santarpia, Chansong Kim, Zehua Chen, Sana Mahmoud, Yun Ling, Alexander Brown, Qian Chen, Guoliang Huang and Jingwei Xe. 

Funding for the study was provided by grants from different organizations, including the National Science Foundation, Office of Naval Research, National Institute of General Medical Sciences, National Institute of Arthritis and Musculoskeletal and Skin Diseases, and the Air Force Office of Scientific Research. 

The authors assume sole responsibility for the content of the study, and their views do not necessarily reflect those of the funding agencies.