Fig. 2: Theoretical analysis and sensing performance of the flexible pressure sensor.

a Schematic diagram of the gradient spherical crown microstructure. b Schematic diagram of the charge transfer process when the sensor is under pressure. c The potential well model of the charge transfer before and after contact. d Simulation results of displacement of the spherical crown pressure sensors under different pressure loads. e The voltage and current frequency response curve of the sensor. f Sensitivity response curve without static pressure load. g Sensitivity response curve under different static pressure load.