Pressure-sensing performance of micro-dome sensor. (a) Photograph of 2B-sensor on the fingertip. (b) Schematic of one-channel (1B-sensor) and two-channel tactile sensor (2B-sensor), and the relative resistance variations of 1B-sensor and 2B-sensor under different pressures. (c) Relative resistance variation of the 2B-sensor during a 2 kPa pressure loading-releasing cycle. (d) Relative resistance variation of 2B-sensor with increasing pressure (1, 2 and 3 kPa). (e) Relative resistance variation of 2B-sensor with increasing subtle pressure (5, 10 and 15 Pa). (f) Relative resistance variation under different loads. (g) Response time of 2B-sensor under pressure 2 kPa. (h) Piezoresistive repeatability of the 2B-sensor under repeated loading/unloading at a pressure of 2 kPa for 5000 cycles. (i) Tactile sensing process of 2B-sensor moving and recognizing Braille “Q”, and tactile signals detected by the 2B-sensor when compressing the convex Braille letters Q, A, B and C.