A Highly Sensitive Tactile Sensor Using a Pyramid-Plug Structure for Detecting Pressure, Shear Force, and Torsion

Sensors that detect and discriminate external mechanical forces are a principal component in the development of electronic tactile systems that can mimic the multifunctional properties of human skin. This study demonstrates a pyramid-plug structure for highly sensitive tactile sensors that enables them to detect pressure, shear force, and torsion. The device is composed of pyramid-patterned ionic gel inspired by neural mechanoreceptors and engraved electrodes. Based on a pyramid-plug structure, the deformation mechanism differs between different types of external mechanical loadings. The sensor provides the high sensitivities of 1.93 kPa ⁻¹ , 29.88 N ⁻¹ , and 3.39 (N cm) ⁻¹ , and a wide range of detection for tactile daily activity. Moreover, this tactile sensor could work through either of the two transduction methods (capacitive transduction and piezoresistive transduction). It is shown that this tactile sensor can be used to monitor changes in electrical signals ranging from those caused by human breathing to those caused by arbitrary multiplex human touching.