Strain-Insensitive Self-Powered Tactile Sensor Arrays Based on Intrinsically Stretchable and Patternable Ultrathin Conformal Wrinkled Graphene-Elastomer Composite

Tissue-like intrinsically stretchable electronics have attracted ever-increasing study attention in recent years as they can form intimate interfaces with skin, endowing devices monitoring tactile and physiological signals with the negligibly constraining movement of the human body. However, harsh mechanical deformation inevitably leads to degradation of or even destroys the electronic properties of the devices. Strain-insensitive self-powered triboelectric tactile sensor arrays based on wafer-scale patterned and intrinsically stretchable nanoscale thin conformal wrinkled graphene-elastomer composite material are demonstrated here. By regulating the wrinkle structure of the composite, the stretchability performance of the material can be optimized. The fabrication process of the composite can be readily incorporated into photolithography and shadow mask techniques without high temperature, annealing, etching, or organic solvents operating. An intrinsically stretchable semitransparent pressure sensor array is created, which can be stretched to 100% strain without visible signals output degradation. The theoretical modeling points out that the unique conformal wrinkle structure is the key element that attributes to the strain-insensitive property of the device. This work offers an alternative approach for the design of novel graphene-based strain-insensitive stretchable soft electronic devices.