A Bionic Gecko Suction\nCup Piezoresistive Sensor with\nIntegrated Patterned Electrodes for Limb Movement and Physiological\nElectrical Signal Detection

Flexible wearable electronic devices are widely used\nin human health\nmanagement, but most wearable sensors have a single function. A portion\nof the sensors with multiple detection functions has complex preparation\nprocesses and high costs. In this article, we propose a bionic gecko\nsuction cup piezoresistive sensor with integrated patterned electrodes,\nwhich has high-sensitivity piezoresistive sensing and can be used\nfor limb movement and physiological electrical signal detection. The\nelastic base layer of this sensor is cast on a mold using poly(vinyl\nalcohol)/glycerol, and its upper surface is coated with a natural\nlatex/carbon nanotube conductive layer to prepare a bionic gecko suction\ncup high-sensitivity piezoresistive structure. It has a minimum piezoresistive\nresponse of 0.5 kPa, a sensitivity of 8121.7 kPa<sup>–1</sup> at an external pressure of 4 kPa, and a response time of 30 ms/recovery\ntime of 20 ms. After the lower surface of the elastic substrate layer\nwas coated with a natural latex/carbon nanotube conductive layer,\na patterned metallic conductive layer with a vertical fence pattern\nwas prepared on the conductive layer using screen printing. The patterned\nmetal conductive layer further reduces the initial resistance of the\nconductive layer on the lower surface and, at the same time, increases\nthe sensitivity of the conductive layer, which can be used for the\ndetection of limb movement and physiological electrical signals.