Cone-Shaped Electrodes for Capacitive Tactile Sensors with High Sensitivity and Broad Linearity Range

Flexible tactile sensors with high sensitivity typically suffer from a dramatically reduces pressure resolution with increasing pressure, resulting in narrow linear ranges and limited application scenarios. Herein, a capacitive tactile sensor based on cone-shaped electrodes (CSE) that can maintain high sensitivity over a broad linearity range is proposed. The linear response comes from the novel sensing mechanism based on the change in the facing electrode area and the rational design of the conical architecture. Finite element analysis (FEA) confirms that the interfacial contact area between the elastic electrodes and the dielectric layer can respond linearly to pressure over a broad spectrum. Based on this strategy, the fabricated sensors perform a high sensitivity (0.23 kPa-1) and superior linearity (R2 = 0.999) across a wide pressure range of up to 130 kPa. The sensors demonstrate several key features, such as good repeatability, fast response speed, low detection limit, and high durability. These attributes enable the successful use of the sensors for monitoring artery pulses and providing weighting capabilities to robots, showing promising potential for applications in daily health monitoring and human-machine interaction. A flexible capacitive tactile sensor based on cone-shaped electrodes is hereby proposed. The sensor can maintain both high sensitivity and wide linearity range. The fabricated sensor samples being conformally attached to the wrist enable arterial pulse monitoring, and can also be integrated into electric hand jaws for linear weight sensing.image