a–c, SEM images of underexposed, normally exposed, and overexposed microstructured electrodes at the same one-dimensional speckle size of σ1 = 2.5 μm. Insets show the magnified SEM images. d–f, SEM images of overexposed microstructured electrodes at σ2 = 5 μm, σ3 = 10 μm, and σ4 = 15 μm.

a, the PDMS–PVDF–PDMS sandwich structure, b, Relative capacitive variation-pressure curves of capacitive pressure sensors with different PDMS electrodes.