In various embodiments, a cooling assembly includes a heat-generating device, a metal inverse opal (MIO) layer, a shared coolant reservoir, a passive heat exchange circuit, and an active heat exchange circuit. The MIO layer is bonded to the heat-generating device. The shared coolant reservoir contains a coolant fluid. The passive heat exchange circuit directs coolant fluid from the shared coolant reservoir through the MIO layer and back to the shared coolant reservoir. The active heat exchange circuit includes a pump and a heat exchanger, wherein the active heat exchange circuit draws the coolant fluid from the shared coolant reservoir through the heat exchanger and returns the coolant fluid to the shared coolant reservoir.