Graphene-Copper Hybrid Thermal Straps for Cryogenic Instruments and Optical Systems

The development of next generation materials with enhanced thermal and/or electrical conductivity will be beneficial for both terrestrial and space applications, ranging from thermal links for conduction cooling of cryogenic instruments and optical systems, mirror substrates for space telescopes, coolant tubes for heat exchangers and deployable radiators, space landing systems, to high powered electronics and beyond. The cryogenic cooling systems are essential for the advancement of terrestrial and space's science goals, which enable new capabilities on sensors, detectors, and accelerators, such as for near- and mid-IR instruments on SmallSats and CubeSats for Earth and Lunar observations, for cooling of far- and mid-IR optics, and for extracting heat dissipation of superconducting radio frequency cavity. High conductive thermal straps play a critical role in balancing heat dissipation and reaching the operating temperature of the instruments. The sluggish conduction cooling rate of conventional thermal straps made from copper, aluminum, or graphite hinders the application of thermal straps on the cryogenic cooling systems. Within this context, we will discuss an efficient, scalable, manufacturing-ready approach to produce high conductive graphene-copper hybrid foils and demonstrate their application in thermal straps for the conduction cooling of cryogenic instruments and optical systems. This technology utilizes the intrinsic physiochemical, thermal, and mechanical properties of graphene and copper matrix, combined with advanced electrodeposition techniques for hybrid material fabrication. An innovative manufacturing process based on the use of pulsed electric fields and the combination of electrodeposition and electrophoretic deposition (EPD), have been developed for controlled, reproducible, scalable production of graphene-copper hybrid foils/coatings. The hybrid exhibited enhanced conductivity and mechanical strain for fast conduction cooling processes. Next step, we will work on the thermal strap fabrication using synthesized graphene-copper hybrid foils and their performance evaluation. Acknowledgements: The financial support of DOE SBIR program through grant No. DE-SC0021676 (Phase I&II) is acknowledged.