Flat Silk Cocoon Pressure Sensor Based on a Sea Urchin-like Microstructure for Intelligent Sensing

Developing high-performance wearable electronic devices based on natural materials with unique structures has become a research hot spot in the field of flexible electronics. Here, taking advantage of natural flat silk cocoon (FSC) by controlling the spinning process of Bombyx mori, sea urchin-like sunflower pollen loaded with MXene nanosheets was sprayed on the FSC at a fixed time interval to fabricate multi-layered piezoresistive sensors. The sea urchin-like structure of SFP is beneficial to MXene loading, and the good elasticity of sunflower pollen can withstand a large mechanical deformation. The prepared pressure sensor has a high sensitivity of 0.028 kPa–1 and good durability, and it can respond quickly to the applied pressure changes (response/recovery times are 140 ms/130 ms, respectively). With these excellent sensing performances, the fabricated sensors are capable of monitoring human physiological activities and physiological signals and can be applied in information encryption transmission with the combination of the Morse code. The pressure sensor developed based on the natural FSC structure shows broad application prospects in the field of flexible wearable electronic devices.