Thermally-Resilient Soft Gripper for Space Debris Removal.

Space debris poses a significant and growing threat to orbital operations, demanding urgent solutions. Soft manipulators, with their adaptability to various shapes and sizes, present a promising approach to mitigate this concern and facilitate orbital maintenance tasks. Challenges such as radiation, vacuum, and microgravity are significant, but the predominant issue is ensuring these devices operate effectively in the extreme temperature swings from -180{\deg}C to over 200{\deg}C. The majority of soft materials become brittle and hard due to crystallization at cryogenic temperatures or undergo drastic shifts in their elasticity near their melting points. This work pioneers experiments using liquid nitrogen to simulate cryogenic conditions and heat guns for elevated temperatures. It derives insights into the behavior of these materials, leading to the design of a soft gripper tailored for space debris removal in LEO orbits. The multi-layered design leverages the properties of thermoplastic polyurethane at low infill rates for lightweight inherent flexibility, silicone rubber ensuring structural integrity, PTFE (Teflon) for unparalleled thermal stability, and aerogel for insulation. The nylon-crafted tendon-driven mechanism incorporated uses molybdenum disulfide grease as a lubrication layer for cryogenic temperatures. The insights from this experiments and the modeling of the temperature-driven property alterations are pivotal for the advancement of soft manipulators tailored for on-orbit operations.