Fig. 1: Transparent pressure-calibratable interference electrotactile actuator.

a Schematic layouts, and structural designs of the device composed of an electrotactile actuator array and pressure-sensitive transistor array. The device directly contacts the skin surface of the finger (left). b SEM image showing stimulating electrode and a reference electrode on the electrotactile actuator. Scale bar, 200 µm. Magnified SEM image showing the Pt nanocluster on stimulating electrode. Scale bar, 8 µm (inset). c Optical transmittance spectrum of the transparent pressure controllable electrotactile device range from 250 nm to 950 nm wavelength. d Impedance graph comparing ITO-Pt and pristine ITO over the frequency range from 200 Hz to 1200 Hz e Cyclic voltammetry graph recorded at a sweep rate of 100 mV s⁻¹. f Real-time detection of relative change in drain current of the pressure-sensitive transistor of TPIEA at pressure ranges from 5 kPa to 75 kPa. g Relative changes in drain current of the pressure-sensitive transistor of TPIEA by the applied pressure at the ranges from 5 kPa to 300 kPa, and the pressure sensitivity of pressure sensor (red line).