Integrated Design and Fabrication of Pneumatic Soft Robot Actuators in a Single Casting Step

TL;DR

This paper introduces an integrated design and fabrication method for pneumatic soft robot actuators that simplifies production by combining mold creation and actuator casting into a single step, reducing time and cost.

Contribution

The authors present a novel single-step casting process for soft actuators using 3D-printed molds and sacrificial cores, enabling rapid, low-supervision fabrication of complex soft robots.

Findings

Successfully fabricated three bio-inspired soft robots with different motions

Reduced fabrication iterations and supervision compared to traditional methods

Demonstrated versatility and effectiveness of the integrated approach

Abstract

Bio-inspired soft robots have already shown the ability to handle uncertainty and adapt to unstructured environments. However, their availability is partially restricted by time-consuming, costly and highly supervised design-fabrication processes, often based on resource intensive iterative workflows. Here, we propose an integrated approach targeting the design and fabrication of pneumatic soft actuators in a single casting step. Molds and sacrificial water-soluble hollow cores are printed using fused filament fabrication (FFF). A heated water circuit accelerates the dissolution of the core's material and guarantees its complete removal from the actuator walls, while the actuator's mechanical operability is defined through finite element analysis (FEA). This enables the fabrication of actuators with non-uniform cross sections under minimal supervision, thereby reducing the number of iterations necessary during the design and fabrication processes. Three actuators capable of bending and linear motion were designed, fabricated, integrated and demonstrated as three different bio-inspired soft robots, an earthworm-inspired robot, a four-legged robot, and a robotic gripper. We demonstrate the availability, versatility and effectiveness of the proposed methods, contributing to accelerating the design and fabrication of soft robots. This study represents a step toward increasing the accessibility of soft robots to people at a lower cost.