The design and development of a soft robotic gripper

Abstract

Soft robots are a unique class of robots, made entirely of soft materials (elastomeric polymers), inspired by animals that do not have hard internal skeletons. Soft robotic structures permits continuous and responsive localized deformation. These properties of soft robots make them suit-able for gripper arms that can be used to handle fragile and delicate objects. In this work, Pnuematic Networks (Pneu-net) are designed in the structure, which is made up of a series of channels and chambers inside an elastomer. These channels inflate when pressurized, creating motion. The material of choice was selected to be LSR220 Series silicone rubber due to its elastic properties and ease of manufacturing. The Computer Aided Design (CAD) model of the actuator is initially developed and then a mold is prepared accordingly for it and we use Rapid Prototyping (RPT) to make the mold. The liquid silicone is then mixed with catalyst and poured in the mold and a plain sheet with cloth embedded in between is prepared for the strain layer. These two layers are then stuck using silicone and when air pressure is supplied, the mismatch strain in layers leads to the bending action of the actuator. Improvements from the traditional silicon-based actuators are tear resistance, uniform pressure distribution, faster and easier manufacturing.