Modular and Reconfigurable Wireless E-Tattoos for Personalized Sensing

In the past few years, ultrathin and ultrasoft epidermal electronics (a.k.a. e-tattoos) emerged as the next-generation wearables for telemedicine, mobile health, performance tracking, human-machine interface (HMI), and so on. However, it is not possible to build an all-purpose e-tattoo that can accommodate such a wide range of applications. Thus, the design, fabrication, and validation of modular and reconfigurable wireless e-tattoos for personalized sensing are reported. Such e-tattoos feature a multilayer stack of stretchable layers of distinct functionalities-a near field communication (NFC) layer capable of wireless power harvesting and data transmission, a functional circuit layer, and a passive electrode/sensor layer. These layers can be disassembled and swapped out multiple times to form different e-tattoos of different sensing capabilities. Such modular and wireless e-tattoos can be rapid-prototyped via a dry, digital, and cost-effective fabrication process-the "cut-solder-paste" process. They have been successfully applied to wirelessly measure a variety of biometrics.