Solid-Liquid Hybrid Thermal Interfaces for Low-Contact Pressure Thermal Switching

Switchable thermal interfaces allow controlled modulation of thermal conductance and are a key enabler of microdevices and systems that require reconfigurable heat transfer paths. We report a solid-liquid hybrid thermal interface for reliable low-contact pressure (<1 kPa) switching with on-state thermal contact resistance <15 × 10−6 m2K/W. Reduction in the thermal resistance of hybrid interfaces created through electroplating was evaluated using transient pulsed heating measurements and thermal time constant characterization. Compared with pure liquid-mediated interfaces and direct solid-solid contacts reported previously, the hybrid interface shows superior thermal performance under the same loading pressure while avoiding the use of liquid metals. The hybrid interface may be readily used with low-power electrostatic or Lorenz force-based actuators as part of integrated thermal microdevices.