Figure 2.

Schematic of the flexible capacitive pressure sensor and SEM images of polystyrene (PS) microspheres. (a) Schematic of the capacitive pressure sensor; (b) Deformation of the pressure sensors with and without one-dimensional pyramid structure PDMS electrodes; (c) Pressure sensor array with 2 × 2 sensing element; (d) SEM image of PS microspheres at low and high amplification; Morphology and displacement changes of the flexible sensor (e) before and (f) after compression caused by application of external pressure.