A stretchable epidermal sweat sensing platform with an integrated printed battery and electrochromic display

Abstract The lack of compact integration, including fusing of skin-interfaced direct, rapid independent data visualization along with light, safe stretchable batteries, hinders progress towards the creation of fully autonomous comprehensive wearable monitoring platforms. Here we present a highly integrated epidermal sensing platform combining electrochemical sensors with stretchable battery and ultra-low power digital display that instantaneously visualizes the results via 10 individually addressable electrochromic pixels. The all-around stretchable patch can operate independently as a standalone device to directly display the concentration of various electrolytes or metabolites, freeing it from any wired or wireless connection to other equipment. Fabricated via high-throughput printing of customized elastomeric inks, the integrated system presents robust mechanical performance, enduring over 1500 stretching cycles without affecting its sensing and display capabilities. The fast-responding display exhibits stability over 10,000 ON/OFF cycles, and upon coupling with the high-performance stretchable battery, can serve 14,000 sensing sessions in a week-long usage. Merging ultra-low power consumption, independent operation, rapid data display and superior mechanical performance, this fully autonomous multifunctional self-sustainable wearable sensing platform is of high practicality and convenience for diverse practical applications in professional sports, personalized wellness management, and beyond.