I. Introduction
The contact surface design plays a key role to influence the grasping success in object manipulation. The grasp robustness is closely related to the physical contact between the robotic finger and the target object, which is modulated by the amount of force exerted at the finger. Recent research has been devoted to the adoption of model-based [1], [2], [3] or learning-based algorithm [4], [5], [6], [7] development for finding the optimal grasping point or posture, the sensing and control of fingertip while in contact with the object for refined motor function [8], the development of novel grasping mode through mechanism design at the finger [9], as well as the optimal number of fingers for successful grasp [10]. The design and development of an effective finger surface design, even without extra sensing or motor control, remains a challenging research topic that offers a simplified, practical, and cost-effective value in industrial applications.