US Patent 9992911 Controllable conductance thermal interface

A thermal transfer system for reducing temperature cycling of an electronic device. The thermal system includes a thermally conductive device to which the electronic device is mounted, a heat sink and a thermal rail mounted to the heat sink. The thermal system further includes a plurality of shape memory alloy (SMA) elements extending through aligned openings in the rail and the thermally conductive device, where the SMA elements are shaped in a deformed wire-like configuration and attempt to return to an undeformed spring-like configuration when the plurality of SMA elements are heated above a transition temperature so as to increase a heat transfer contact pressure between the thermally conductive device and the rail.