Compact Modeling of Stretchable Printed Liquid Metal Electrical Interconnects

One method for fabricating stretchable electronics uses highly-stretchable electrical interconnects and traditionallypackaged integrated circuits (IC) encapsulated in a stretchable substrate, similar to a printed circuit board (PCB) [1] , [2] . Unlike a conventional PCB with rigid copper interconnects, when using stretchable conductive materials such as liquid metal, the electrical characteristics of the chip-to-chip interconnects will change as the substrate is stretched or compressed. For robust digital communication over these stretchable interconnects, these changing electrical characteristics must be known to the circuit designer and simulated in conjunction with communication circuits. In this work, we present a compact modeling approach for modeling the resistance and capacitance of printed liquid metal paste interconnects. The models are empirically tuned using measured resistance and capacitance values from stretchable two-wire interconnect test devices, and both simulated and measured results are presented.