Wearable System Design using Intrinsically Stretchable Temperature Sensor

This paper explores system integration aspects for stretchable electronics. We consider a prototypical wearable device that combines (1) a conformal and stretchable transducer patch, (2) high-fidelity readout electronics based on rigid CMOS integrated circuits (ICs), and (3) flexible and stretchable interconnects that bridge the two mechanical domains. The considered temperature sensing element is based on organic thin-film transistors (OTFTs) and requires bias currents in the sub-microampere regime. We show how to meet this requirement using standard commercial parts. Furthermore, we present an interconnect solution based on encapsulated liquid-phase conductors and show its measured I-V curves under strain. The design guidelines and parameters obtained from this study can be used to aid the development of similar wearable sensing platforms.