A major challenge in self-powered wearable sensors for health care monitoring is distinguishing different signals when they occur at the same time. Researchers from Penn State and China's Hebei University of Technology addressed this issue by uncovering a new property of a sensor material, enabling the team to develop a new type of flexible sensor that can accurately measure both temperature and physical strain simultaneously but separately to more precisely pinpoint various signals.
"This unique sensor material we've developed has potentially important applications in health care monitoring," said Huanyu "Larry" Cheng, James L. Henderson, Jr. Memorial Associate Professor of Engineering Science and Mechanics (ESM) at Penn State and co-corresponding author of the study published in Nature Communications. "By accurately measuring both temperature changes and physical deformation or strain created by a healing wound and measure that by separating the two signals, it could revolutionize the tracking of wound healing. Doctors could get a much clearer picture of the healing process, identifying issues like inflammation early on."
The researchers aimed to accurately measure temperature and strain signals without cross talk by using laser-induced graphene, a two-dimensional (2D) material. Like all 2D materials including regular graphene, laser-induced graphene is one to a few atoms thick with unique properties, but with a twist. Laser-induced graphene (LIG) forms when a laser heats certain carbon-rich materials - like plastic or wood - in a way that converts their surface into a graphene structure. The laser essentially "writes" the graphene directly onto the material, making it a simple and scalable way to produce graphene patterns for electronics, sensors and energy devices.
