Electromechanical performance of flexible sensor based on 3D printed biomimetic all-PDMS-coated multistage structure: toward kinesiology monitoring and human-machine interaction

Flexible pressure sensors have become a research hotspot in human-computer interaction, and health applications because of their lightweight, high sensitivity, and easy integration. Traditional single microstructure sensors cannot meet the demands of low detection limit, high sensitivity, or expansive detection range in the current application environment. This paper proposes an all-PDMS-coated multi-stage flexible sensor based on an armadillo-mimetic structure that effectively enhances the pressure sensitivity and expands the sensing range. The experimental findings illustrate that the flexible sensor, inspired by the armadillo, exhibits a high sensitivity of 1.032 kPa-1 and detects a minimum pressure of 0.5 Pa, with a broad pressure response range of up to 300 kPa. Furthermore, it has rapid response time and recovery time (40 ms and 40 ms at 3 kPa), excellent stability, and reproducibility over 2000 cycles. Hence, the proposed sensor performs admirably in kinesiology monitoring, object gripping, mechanical hand gripping, and human-machine interaction, making it widely applicable for monitoring pressure changes during different human motions, indicating great potential in smart robotics and wearable devices.