Stronger dielectric-elastomer grippers using spine-like bending structure

• Main Author: Heng, Kim Rui
• Other Authors: Lau Gih Keong
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/68031
• Institution: Nanyang Technological University

Dielectric Elastomer Actuator (DEA) based soft grippers are usually too flimsy to perform the task of pick and place on an object and their payload capacities are rather low. This project developed a very strong and highly versatile soft gripper that can produce large clamping and holding forces. The gripper is developed based on a new design of DEA using stiffer spine-like structure made of 380μm thick Polyvinyl chloride (PVC) sheet. This spine-like structure of high stiffness curls longitudinally upon bonding with a pre-stretched dielectric elastomeric actuator membrane. The actuator finds equilibrium in bending when the pre-stretch is released and it can unfolds by the application of a voltage bias. Such stiff frame is usually not bendable by any pre-stretched elastomer; however, this work demonstrates a new concept of bending stiff frames and fabricating these stronger spine-like grippers. The high stiffness of the structure leads to a stronger, fast-response and lightweight soft gripper, capable of producing large force. The actuator weighs only 3 grams and it has demonstrated a maximum change of bending angle of approximately 90° and a maximum actuation blocked force of more than 160mN for a single actuator.