Multifunctional Thermal Structures Using Cellular Contact-Aided Complaint Mechanisms

Thermal management of spacecraft electronics is a major concern. Passive thermal control promises high reliability and reduced system weight. Cellular contact-aided compliant mechanisms were considered as an avenue to variable thermal conductivity. Thermally-driven deformation creates or breaks contact or modifies contact pressure, thereby controlling heat conduction through an interface. Pressure-dependent thermal contact conductance generates a smooth change between insulating and conducting modes. A topology optimization approach was conceived to maximize performance by placing two materials having very different conductivities. Several designs with good performance under realistic high and low heat loads were generated. Bi-material prototypes were fabricated from polished copper sheet. They achieved good conductance and rapid switching, especially those having low surface roughness. Future 3-D additive fabrication methods could conceivably produce the elegant but complex material and geometric designs contemplated. Continued research is needed to improve the robustness of the optimization scheme, as well as to fabricate and experimentally verify the thermal performance of the resulting designs in practice.