Differentiation of Multiple Mechanical Stimuli by a Flexible Sensor Using a Dual-Interdigital-Electrode Layout for Bodily Kinesthetic Identification.

Human bodily kinesthetic sensing is generally complicated and ever-changing due to the diversity of body deformation as well as the complexity of mechanical stimulus, which is different from the unidirectional mechanical motion. So, there exists a huge challenge for current flexible sensors to accurately differentiate and identify what kind of external mechanical stimulus is exerted via analyzing digital signals. Here, we report a flexible dual-interdigital-electrode sensor (FDES) that consists of two interdigital electrodes and a highly pressure-sensitive porous conductive sponge. The FDES can precisely identify multiple mechanical stimuli, e.g., pressing, positive bending, negative bending, -direction stretching, and -direction stretching, and convert them into corresponding current variation signals. Moreover, the FDES exhibits other exceptional properties, such as high sensitivity, stretchability, large measurement range, and outstanding stability, accompanied by simple structural design and low-cost processing simultaneously. Additionally, our FDES successfully identifies various complex activities of the human body, which lays a foundation for the further development of multimode flexible sensors.