Polymer Swelling Induced Conductive Wrinkles for an Ultrasensitive Pressure Sensor

Deposition of particular layers of solid materials on a swelling polymer leads to the formation of functional wrinkles after the release of polymer strain. Unlike traditional mechanical stretching, polymer swelling could introduce uniform wrinkle structures on complex substrates as a result of isotropic polymer elongation. In this work, conductive silver wrinkles are grown on an elastomer by combining polymer swelling with electroless deposition. By adjusting the cross-linking ratio of polymer substrate or deposition time, the amplitude and wavelength of wrinkles can be tuned to meet demands for ultrasensitive pressure sensors. The detectable pressure limit is successfully reached below 1.0 Pa.