Soft robotic jamming gripper design I

• Main Author: Koh, Jun An
• Other Authors: Chow Wai Tuck
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/167376
• Institution: Nanyang Technological University

Soft robotics technology provides strong potential in serving the food industry, which handles organic products that are more fragile and perishable. This is due to the use of compliant material in soft robotic designs that can adapt to the products being handled. The objective of this project is to design, fabricate and simulate a novel granular jamming soft robotic gripper. Current soft robotic technologies employed in the food industry mainly adopt actuation type solid claw grippers, with considerably fewer developing granular jamming grippers, despite having potential to be safer for handling food items. Furthermore, there is a research gap in terms of testing and simulation of granular jamming grippers in the food industry using simulation tools and methods such as Discrete Element Method (DEM). This project first presents a literature review on the usage of soft robotics in the food industry and soft robotic gripper designs. The project then covers simulations created to represent physical properties of the vacuum bag materials and performing a comparison of actuation type and granular jamming type gripper loads on a Fuji apple. LS-DYNA was used to conduct Finite Element Analysis (FEA) and Discrete Element Analysis (DEA). Subsequently, 3D CAD model designs for the novel granular jamming gripper system were created on SOLIDWORKS. The 3D models were imported for fabrication via 3D printing Fused Deposition Modeling (FDM) and Stereolithography (SLA) methods. Methodology of the three-point bending test simulations served as a basis for understanding DEM as well as simulation of different fabric material combinations for the gripper vacuum bag surface. The results of the simulation showed potential applicable usage in future simulation calibration with material stiffnesses from physical experimentations. Results from the FEA and DEA of the gripper comparison simulations showed that loads caused by the actuation solid gripper on the Fuji apple were close to the yield strength of 0.125 MPa, making the apple subject susceptible to mechanical damage and bruising. While by comparison, maximum stress on the apple caused by the granular jamming gripper showed a 9% reduction, which reduces the risk of damage to the Fuji apple.