Pressure Induced Transition from Wrinkling to Period-Doubling Instability in Flexible Tactile Sensors

Wrinkle structures are widely used in flexible tactile sensors due to ease of fabrication and significant improvement of sensitivity. However, period-doubling instability induced by pressure hinders the improvement of its measure range and accuracy. We conduct experiments and finite element analysis to elucidate the mechanisms and characteristics of period-doubling instability. Influence of prestretch and friction coefficient on critical load is discussed. A pre-shaping method is proposed to restrain period-doubling and extend the limit of pressure measurement. The influence of defects and average effect in actual flexible tactile sensors are discussed. The profound comprehension of period-doubling instability can instruct the design of flexible tactile sensors with high stability and accuracy, and give inspires to new concepts of flexible tactile sensors with versatile functions and unique capabilities.