Fabrication Techniques of Stretchable and Elastomer-Fabric Electroadhesion Samples for Implementation on Devices with Space Application

This study will characterize materials and fabrication techniques for electroadhesion (EA) elastomerfabrics and stretchable EA pads with the objective of manufacturing efficient, space-rated EA devices. EA is characterized by an electrostatic force produced by inputting a DC signal at high voltage (near 5 kV) into adjacent planar electrodes. An electric field is generated from the electrodes to the substrate of choice. Adhesion of the pad with the substrate occurs by Coulombs Force for conductive substrates and Van der Waals Force for nonconductive substrates. This electrostatic adhesion phenomenon allows for active ”on-off” adhesive capabilities. For the purpose of space application, metal electrodes such as Aluminum and space-rated insulating materials should be considered including Kapton polyimide and polypropylene. Fabrication of stretchable EA samples consists of elastomers as insulating materials and liquid metal or conductive polymers as electrodes. Liquid metals, including gallium-indium alloy, as electrodes embedded in an insulating polymer in various patterns will be studied in a vacuum environment, and optimized for application in spacecraft docking, astronaut space suits, and spacewalk gripper devices. The magnitude of the electroadhesive force as the EA pads are stretched must be studied in order to fabricate efficient pads for application, and the limitations of the pads must be determined. In approach to obtaining goals of the study, elastomer-fabric EA pads will be fabricated and shear adhesive forces will be measured, then compared to the controls, which include standard EA pads and PDMS. After it is shown that adding fabric to EA pads improves adhesive forces, materials and fabrication techniques will be optimized, especially with application to space environments. Static response tests will determine the maximum shear force between EA samples and substrate materials, chosen as common materials found in a space environment. Measurements will be acquired from pull tests with an Instron Machine. Further, the pads will be designed in geometries specific to applications in astronaut gripper devices and spacecraft docking. EA prototype devices will be dynamically tested. This study has perceived significance pertaining with NASA interests, specifically on TABS element 4.6.3 in using EA technology as a docking and capture mechanism. As a lightweight, low cost, and low power alternative to traditional mechanical docking mechanisms, EA mechanisms in alignment with TA 4.6.3.1 will be integrated as docking and automated rendezvous systems. Advancing scientific knowledge of EA effects, this technology provides alternative capture devices for future Mars missions, specifically for the Human Exploration and Operations Mission Directorate. Additionally, EA grippers and grabber claws may be used by astronauts on spacewalks to maneuver or collect rocks for scientific studies on Mars. This study will obtain an understanding of the physics of both elastomer-fabric and stretchable EA pads for these applications.