Abstract
In robotic-assisted surgery (RAS), traditional surgical instruments without sentient capability cannot perceive accurate operational forces during the task, and such drawbacks can be largely intensified when conducting sophisticated tasks using flexible and slender arms with small end-effectors, e.g., in gastrointestinal endoscopic surgery (GES). In this work, we propose a micro-electro-mechanical systems (MEMS) piezoresistive 3-axial tactile sensor for GES forceps, which can intuitively provide surgeons with online force feedback during robotic surgery. The fabrication process of MEMS enables the sensor chips to possess dimensions of miniaturization. The fully encapsulated tactile sensors can be effortlessly integrated into miniature GES forceps, which feature a slender diameter of just 3.5 mm and undergo meticulous calibration procedures least squares method. In experiments, the sensor's capability to accurately measure directional forces up to 1.2 N in Z axis was validated, demonstrating an average relative error of only 1.18% compared to the full-scale output. The results indicate that this tactile sensor can provide effective 3-axial force sensing during surgical operations, such as grasping and pulling, and in ex-vivo testing of the porcine stomach. Its characteristics of compact size, high precision, and integrability establish solid foundations for clinical application in the operating theatre.