Design and Development of a Topology-Optimized Three-Dimensional Printed Soft Gripper

Abstract

In the past decade, a rich repertoire of soft robots, designed from biomimetic and intuitive approaches, has been developed to overcome challenges faced by their rigid-bodied counterparts. However, these design approaches are greatly limited by the designers' experience and inspiration. In this article, the structural design problem is mathematically modeled under the framework of topology optimization, and solved by a new implementation tool that combines Abaqus/CAE and Matlab coding. Herein, a pneumatic soft gripper with two identical fingers was developed as a practical application. To fulfill the grasping task, each gripper finger is optimized to achieve its maximal bending deformation. The optimized gripper fingers are in high consistence with human fingers as indicated by pseudo-joints. Thereafter, the optimized gripper fingers are directly fabricated by three-dimensional printing technique with unprecedented fidelity regardless of high geometric complexity. Experimental results show that the gripper can grasp an elastic balloon, and each gripper finger is able to undergo a [Formula: see text] free travel bending and exert 0.23 N grasping force upon 0.06 MPa actuation pressure. The proposed approach is freely extendable to develop other types of soft robots and this represents an important step toward the goal of designing and fabricating soft robots automatically.

Design and Preliminary Testing of a Continuum Assistive Robotic Manipulator

“…Relatedly, fitting the manipulator with a capable gripper would improve performance. A variety of suitable soft grippers which could be integrated with a continuum manipulator have been described in the literature [27,[35][36][37][38][39][40][41].…”

Topology Optimization and Prototype of a Multimaterial-Like Compliant Finger by Varying the Infill Density in 3D Printing

“…2 Soft and compliant robotic systems generally have the potential to handle unexpected interactions with unstructured environments or humans in more sophisticated ways than rigid robots. 3,4 rubber-like resins, 12,14 vulcanized rubbers, 18,19 and thermoplastic elastomers (TPEs) 8,9,11,20 are often used in prototyping soft grippers.…”

“…29 The algorithms of topology optimization methods are extensively investigated in the literature over the past several decades [29][30][31][32][33] and have been used in developing various soft robotic grippers. [8][9][10][11]14,16,17,20,[34][35][36][37] For example, Wang et al 10 developed a cable-driven two-finger soft gripper with multiple input ports; a topology optimization method is used to synthesize the compliant finger considering multiple working conditions. A three-finger cable-driven soft robotic gripper presented by Chen et al 35 is prototyped with a 3Dprinted TPE and can be used to grip objects up to 1 kg.…”

Design Optimization of a Pneumatic Soft Robotic Actuator Using Model-Based Optimization and Deep Reinforcement Learning

“…Caasenbrood et al (2020) presented a topology optimization scheme to find the optimal design of a pressure-driven soft robots structure using the Solid Isotropic Material Method with Penalization (SIMP) in which they assign a continuous density variable for each element. Zhang et al (2018) provided a method for topology optimization of a pneumatically actuated soft gripper by recasting the design problem mathematically and using Solid Isotropic Material with Penalization method which uses densities of the discretized elements as design variables. The above-mentioned methods focus primarily on optimizing the weight-strength ratio and do not directly employ advanced optimization techniques, such as DRL.…”