Solid Liquid Hybrid Thermal Interfaces for Low Contact Pressure Thermal Switching

Abstract

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 solidliquid hybrid thermal interface for reliable lowcontact pressure (<1 kPa) switching with onstate thermal contact resistance <15 أ— 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 liquidmediated interfaces and direct solidsolid 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 lowpower electrostatic or Lorenz forcebased actuators as part of integrated thermal microdevices.