Finger-inspired rigid-soft hybrid tactile sensor with superior sensitivity at high frequency

Among kinds of flexible tactile sensors, piezoelectric tactile sensor has the advantage of fast response for dynamic force detection. However, it suffers from low sensitivity at high-frequency dynamic stimuli. Here, inspired by finger structure-rigid skeleton embedded in muscle, we report a piezoelectric tactile sensor using a rigid-soft hybrid force-transmission-layer in combination with a soft bottom substrate, which not only greatly enhances the force transmission, but also triggers a significantly magnified effect in d(31) working mode of the piezoelectric sensory layer, instead of conventional d(33) mode. Experiments show that this sensor exhibits a super-high sensitivity of 346.5 pC N-1 (@ 30 Hz), wide bandwidth of 5-600 Hz and a linear force detection range of 0.009-4.3 N, which is similar to 17 times the theoretical sensitivity of d(33) mode. Furthermore, the sensor is able to detect multiple force directions with high reliability, and shows great potential in robotic dynamic tactile sensing.

Automated summary

In this study, a novel piezoelectric tactile sensor is reported, which uses a rigid-soft hybrid force-transmission layer and a soft bottom substrate to improve sensitivity at high frequencies and amplify the effect of the piezoelectric sensory layer. The sensor exhibits super-high sensitivity, wide bandwidth, and a linear force detection range, and shows great potential in robotic dynamic tactile sensing.