Experimental assessment on the contact characteristics of 3D printed flexible poly lactic acid (PLA) soft fingertips

This purpose of this research work primarily focuses on assessing the contact characteristics of a novel 3D printed flexible poly lactic acid (PLA) fingertip exposed to a normal load ranging from 1–750 N. The 3D printed fingertip is pressed against three different target surfaces having concave, convex and flat profiles to facilitate a rational comparison. The growth of contact area is recorded for a wide range of applied normal force against the fingertip on logging sheets and the same is converted in vector format for facilitating digital measurements. From close examination of the results, it may be noted that the rate of growth of contact area follows the parametric relationship a = cN γ . A weighted least squares fit algorithm is used to formulate the parametric relationship based on experimental data. Further, the contact characteristics of the 3D printed fingertip follows the same pattern of soft neoprene fingertip, and it is well in line with the expected results. Hence, it is evident that 3D printed fingertips could be utilized for handling fragile to hard objects and capable of handling multi-profiled objects in dexterous robotic manipulation. Moreover, complex profiled fingertips can easily be manufactured by 3D printing, and it can be considered as a better alternative for conventionally manufactured anthropomorphic robotic grippers. Practical implications of this research will be highly useful for development of soft-fingered robotic grippers for dexterous robotic manipulations.