All-Rubbery Electronic Materials Based Stretchable Electronics, Sensors and Smart Skins

Abstract

To eliminate the mechanical strain on nonstretchable electronic materials while being stretched, the engineering structural design strategy from special mechanical structures or architectures is generally used. An alternative route to eliminating the burden of constructing dedicated architectures and the associated sophisticated fabrication processes is to build stretchable electronics from rubbery electronic materials, which have potential toward scalable manufacturing, high-density device integration, large strain tolerance. In this work, we present the manufacturing of stretchable elastomeric electronics and sensors from all solution processable, scalable and low-cost rubbery semiconductors and conductors without any additional structural design to achieve large mechanical stretchability. We use all commercially available materials as precursors to achieve highly stretchable semiconductors and conductors that can be manufactured in a repeatable and scalable manner and have stable performances under the mechanical stretching. Specifically, we build nanofibril organic semiconductor and metallic nanowires percolated in the elastomeric polymer matrix in a composite format for the rubbery semiconductors and conductors, respectively. The constructed low-voltage operational (< -3V) and elastomeric thin-film transistors from the rubbery semiconductors and conductors achieved a high value of a field-effect mobility for the stretchable organic format of semiconductors and showed a moderate decrease in the mobility under 50% mechanical stretching. The circuits (inverter, NOR, and NAND gate) and an active matrix integrated with pressure sensors show a normal operation under the mechanical stretching strain of up to 50%. Also, stretchable sensors, which include strain, pressure and temperature sensors show reliable sensing capabilities upon the mechanical stretching up to 50%. Furthermore, successful demonstrations of these rubbery electronics as multifunctional artificial robotic skins that can translate hand motions and gestures to provide haptic sensing capabilities present challenging, but still practical potentials for a wide range of applications, such as artificial skins, biomedical implants, and wearable applications.