Abstract: A thermal management system for transferring heat to and from a heat source. The system includes a thermal conductor thermally coupled to the heat source, a pressure dependent thermal conductance element thermally coupled to the conductor, and a heat sink thermally coupled to or thermally separable from the thermal conductance element. An actuator is configured relative to the thermal conductor, the thermal conductance element and the heat sink that controls the compression of the thermal conductance element between the thermal conductor and the heat sink so as to control the transfer of heat therebetween. The thermal conductance element can be compressible TIM element, such as a nanowire array, carbon nanotube forest, polymeric gasket, etc.