At present, the majority of wearable biomarker sensors require onboard batteries to power them. While that’s perfectly acceptable for some use cases, it’s not as well-suited for tasks such as continuous tracking for medical purposes. To solve this problem, researchers from Northwestern University have developed a battery-free soft skin patch that’s able to gather data about the body wirelessly by testing sweat components. In time, the team hopes that this technology will be useful for clinical applications such as cystic fibrosis diagnosis and rehabilitation tracking among stroke survivors.
“We’ve developed a thin, soft microfluidic analysis lab that can laminate to the surface of the skin, where it captures minute quantities of sweat and analyzes key biomarkers related to physiological health, electrolyte balance, and hydration state,” Professor John Rogers, a physical chemist and materials scientist at Northwestern, told Digital Trends. “It brings fluids and chemical analysis into the realm of a skin-interfaced wearable that can operate in real-time in the field. Specifically, it provides the reader with visual information on sweat loss and sweat rate, along with the pH and electrolyte levels, and wireless digital data on glucose and lactate levels — all based on sweat.”
The patch gathers sweat through small pore-like holes, which channel it into tiny collection chambers. Each chamber measures something different. Power is provided via radio waves emitted from connected devices, such as smartphones. This communication also allows the patch to feed back data, which is then read using near-field communication technology.
Unlike many of the projects we cover under the heading of “Emerging Technology,” Northwestern’s research has already led to one product. Having formed a startup called Epicore to commercialize the tech, Northwestern has licensed it to L’Oreal for a skin pH tracker shown off at the recent CES 2019 event. Rogers says that another sport-oriented application will be announced in the coming weeks. This could relate to allowing athletes to see how their bodies are holding up over the course of a competition.
Long-term, however, he believes it will have profound medical applications. “On a slightly longer timescale, we’re developing these platforms as diagnostics for cystic fibrosis and for kidney disease,” he noted.
A paper describing the research was recently published in the journal Science Advances.