An Improved Soft Dielectric for a Highly Sensitive Capacitive Tactile Sensor

This paper presents a novel capacitive tactile sensor that is capable of making highly accurate measurements at low pressure levels, while also being functional within a wide range of pressure. Many researchers have concentrated on sensing applied pressure using methods, such as piezoresistive, optoelectronics, and piezoelectric technologies; but a very popular approach in recent years uses capacitance-based sensing. However, most capacitive sensors, due to the properties of their dielectrics, remain limited by hysteresis and narrow ranges of sensitivity. Our sensor overcomes these restrictions because of the improved soft dielectric that we have constructed. This dielectric features a double-stage microstructure, allowing it to be very sensitive to low pressure while still able to measure a wide range of pressure. The silicone used to construct the dielectric is doped with high permittivity nanoparticles to enhance the response of the sensor. Furthermore, considering the complexity of the dielectric's construction, our fabrication process is relatively simple. In this paper, we describe the design and fabrication of this dielectric and present the results of our sensor's performance.