A heat sink assembly for a cage for a field replaceable computing module includes a heat sink, a thermal interface material (TIM), and an actuation assembly. The heat sink includes a mating surface. The TIM includes a first surface that is coupled to the mating surface and a second surface that is opposite the first surface. Thus, the second surface can engage a heat transfer surface of a field replaceable computing module installed adjacent the heat sink. The actuation assembly includes a shape memory alloy (SMA) element. When the SMA element is in a first position, the second surface of the TIM contacts the heat transfer surface of the computing module. When the SMA element moves to a second position, the second surface of the TIM is moved a distance away from the heat transfer surface of the computing module.