Tactile sensor array laden 3D-printed soft robotic gripper

Abstract

Herein, development of a 3-D printed soft robotic tri-gripper embedded with tactile sensor array is presented. A facile fabrication strategy by 3D-printing thermoplastic polyurethane (TPU) was employed to fabricate the soft tri-gripper consisting of 9 capacitive tactile sensor-laden phalanges. The 3D-printed TPU itself was used as a sensory dielectric for the fabricated tri-gripper. The sensor and interconnect electrodes have been designed to have minimum cross-sensor capacitive coupling with stretchable interconnects to ensure robust integration. The designed sensors were patterned as copper electrodes on top of flexible polyimide film and embedded within the gripper during the 3D-printing process. The sensors were characterised and it exhibited a maximum sensitivity of 2.87 %/kPa. The gripper was tested for up to 100 cycles of compression and expansion. The developed sensory gripper finds application in industrial and agricultural robotics. A sample application in a fruit pick-and-drop task was demonstrated which makes use of both artificial vision and tactile sensing modalities.