Wireless Electronic Tattoos

Abstract

Wearable electronics are finding emerging applications in mobile health, rehabilitation, prosthetics/exoskeletons, athletic training, human-machine interaction, etc. However, our skin is soft, curvilinear and dynamic whereas wafer-based electronics are hard, planar, and rigid. As a result, state-of-the-art wearables can only be strapped or clipped on human body. The development of flexible and stretchable electronics offers a remedy for such challenge. E-tattoos represent a class of stretchable circuits, sensors, and actuators that are ultrathin, ultrasoft, skin-conformable and deformable just like a temporary tattoo. Our group has invented a low-cost, dry and freeform “cutsolder- paste†method for the rapid prototyping of multilayer and reconfigurable wireless e-tattoos. This method has been proved to work for thin film metals, polymers, ceramics, 2D materials and their integration with rigid integrated circuits (ICs). Through a modular and multilayer design, we created e-tattoos that can wirelessly receive power and transmit data through near field communication (NFC) and Bluetooth. Such etattoos can conform to any part of human skin for electrophysiological, mechanical, thermal and optical sensing.