Full-angle adjustable robotic probe based on flexible microstructure array capacitive sensors

Abstract

Surgical robot palpation probes are essential for ensuring safe and precise human-robot interactions. However, existing probes face several limitations, including single-point probes with restricted coverage and low efficiency, and array probes that are bulky and lack flexibility. These limitations hinder achieving efficient detection, minimizing trauma, and providing multi-angle adaptability in complex cavity environments. To overcome these challenges, this paper introduces a fully angle-adjustable robotic palpation probe with a foldable mechanism capable of adjusting from 0° to 180°. This design significantly enhances the probe's adaptability and coverage across multi-angle, multi-form cavity environments. Combining the flexibility of a single-point probe with the high resolution of an array probe enables accurate palpation and rapid detection. The integrated flexible array capacitive sensor, featuring a rotationally thrown microstructure, delivers high resolution (4 mm²), excellent sensitivity (1.2 kPa⁻¹), and fast response time (160 ms). The sensor's graphene electrode layer enhances stretchability and conformity to the palpated surface. Experimental results validate the probe's ability to detect various target shapes, sizes, and positions within simulated complex cavities, providing real-time haptic feedback.