Fig. 3. Characterization of the stretchable pressure sensor’s performance and experimental validation of the mechanism for the strain-unperturbed behavior.

(A) Capacitance responses to pressures from four separately fabricated sensors when they are at 0 and 50% strains. (B) Typical performance repeatability of the sensor under repeated pressure loading and repeated stretching cycles between 0 and 50% strains. C₀ is the initial capacitance, and ΔC is the capacitance change. (C to E) Pressure sensing performances under stretching from the reference sensors without stiffening microelectrodes (C), without ionic effect in the elastomer layer (D), and without soft spacers (E), respectively.