Design and Optimization of Array-Structured Active Layer Geometry for Enhanced Sensitivity in Flexible Piezoresistive Pressure Sensor

Flexible and wearable piezoresistive pressure sensors (FPPS) are attracting great attention for applications in healthcare monitoring, human-machine interfaces, soft robotics, and human motion detection. Developing an efficient sensor with maintained high sensitivity and a wide sensing range remains a significant challenge. In this study, active layer geometry based Flexible Piezoresistive Pressure Sensor (FPPS) are systematically optimized using a finite element method (FEM) based on COMSOL Multiphysics 6.0. Graphene is employed as an active layer with different geometries such as rectangular, trapezium, and pyramid array on a polyethylene naphthalate (PEN) substrate. Simulation results shows that the FPPS integrated with pyramid-array structured (PAS) of graphene layer exhibits a maximum sensitivity of 785 kPa⁻¹ under an external pressure range of 0 to 0.1 kPa, due to its superior stress distribution and deformation characteristics. The proposed FPPS with a PAS graphene layer has excellent potential for wearable and biomedical applications, including rehabilitation monitoring, human-machine interaction, soft robotics, artificial electronic skin, respiration monitoring, and sports monitoring.