A Highly Accurate, Stretchable Touchpad for Robust, Linear, and Stable Tactile Feedback

Abstract A stretchable and steady performance of human–machine interfaces and localized tactile perception is a broad concerning problem. Existing tactile sensors and touchpads claim to be stretchable for location detection failing to offer a location with uniformity during inevitable flexible movements, as well as linearity. The fabrication of a highly stretchable and transparent touch sensor, which is made of hydrogels and PDMS, could simultaneously and precisely determine location and pressure while being stretched or unstretched. It is noteworthy that the sensor introduces a new structure of resistant‐system into stretchable sensors, which needs only four electrodes in 3D helical structure without sacrificing linearity. A few drops of silicone oil are added to the interfaces to prevent the dehydration of the hydrogels, which is a common problem leading to device failure. In the same time, the transparency is improved significantly from 84.3% to 96%. Its interface application is demonstrated by practically using it for drawing, dialing numbers, calculating, and playing cards. Finite element analysis based on Ogden models indicates that the sensor shows instant response without delay, which is vital for super‐elastic materials based electronics.