A micro-tactile sensor for in situ tissue characterization in minimally invasive surgery

This study presents and characterizes a micro-tactile sensor that can be integrated within MIS graspers. The sensor is capable of measuring contact forces and characterizing softness. The grasping forces are distributed normally, though in some cases concentrated loads also appear at the contact surfaces. In the latter case, the position of the concentric load can also be determined. This enables the sensor to detect hidden anatomical features such as embedded lumps or arteries. The microfabricated piezoelectric-based sensor was modeled both analytically and numerically. In a parametric study the influence of parameters such as length, width, and thickness of the sensor was studied using a finite element model. The sensor was microfabricated and tested using elastomeric samples. There is a good conformity between the experimental and theoretical results.