Design and fabrication of integrated soft sensor for soft gripper using multi-material 3D printing

• Main Author: Li, Xin
• Other Authors: Yeong Wai Yee
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/167961
• Institution: Nanyang Technological University

In the field of soft robotics, integration of sensors into soft, flexible grippers poses significant challenges due to their high-dimensionality and the complexities in developing soft sensors. Selecting suitable sensor types and their placements, while maintaining the dynamics of the soft system, is a critical hurdle. This dissertation focuses on the design, integration, and testing of 3D printed piezoresistive sensors for soft grippers to evaluate their gripping performance. In this study, three types of sensors were designed: Sponge Sensor, Oreo Sensor, and Bridge Sensor. Experimental results and analysis show that the Bridge Sensor design is feasible, while the other two designs face manufacturing challenges and exhibit poor performance. The Bridge Sensor is integrated into the gripper fingers and its sensing performance is tested. The study investigates the design parameters of the Bridge Sensor, including the sensor infill and placement orientations, the gripper infill density. These parameters have been verified through cyclic loading experiments. The obtained results indicate that 0° and 45° infill orientations offer stable sensing performance, and the perpendicular placement orientation outperforms others. In terms of infill density of gripper, 10%, 15%, and 20% demonstrate good sensing performance within a large force range, but only the 20% infill density of gripper exhibits stable and sensitive performance within a small force range. The findings provide valuable insights for the development of smart multi-material grippers with integrated soft sensors for various gripping applications. Keywords: Piezoresistive sensor, soft gripper, 3D multi-material printing