Development of a Piezo-Capacitive Tactile Force Sensor for Measuring Static and Dynamic Forces in Minimally Invasive Robotic Surgeries.

Abstract

Taking inspiration from the human tactile system, this paper presents a sensitive biomimetic multimodal tactile sensor designed for the discrimination of static and dynamic forces. The multimodal tactile sensor integrates a piezoelectric-capacitive tandem mechanism to respond to dynamic and static forces, respectively. The sensor is capable of detecting normal direction dynamic force signals using a piezoelectric component operating in the d33 mode, while static force detection is achieved through a capacitive component. The capacitive sensing part features a unique configuration with a top electrode and two sets of differential pairs of electrodes for force measurement in the X and Y shear axes, along with a single electrode for normal force measurement. This innovative design allows for precise force measurements across multiple directions. Experimental characterization of the sensor was conducted for static, quasi-static, and dynamic forces, demonstrating its capability to respond to dynamic forces up to 60Hz. The force sensitivity of the sensor for normal forces is measured at 0.084 pF/N for the capacitive part and 0.035 V/N for the piezoelectric part, within a force range of 10N. In the shear X and Y directions, the sensor exhibited sensitivities of 0.027 pF/N and 0.029 pF/N, respectively, within a force range of 1.2N. These results highlight the sensor's high sensitivity and accuracy in force measurement. Given its dimensions, performance, and capabilities, the presented sensor holds significant potential for applications in minimally invasive robotic surgeries, robotics, wearable devices, and prosthetics. Its ability to accurately measure both static and dynamic forces makes it a valuable tool for enhancing tactile feedback and control in various advanced technological applications. This sensor represents a substantial advancement in the development of biomimetic tactile sensing devices, paving the way for more sophisticated and responsive systems in both medical and non-medical fields.