Abstract: Embodiments include a heat sink cell comprising a first reservoir having a first volume of space and a first material stored in the first volume of space. The first material provides a first heat sink thermal operating range for the transfer of heat. The cell comprises a second reservoir and a second material stored in the second reservoir. A shape memory alloy (SMA) closes an opening of the second reservoir. The SMA is responsive to a temperature change of the first material or external sources to automatically open the opening so that the first material or the second material spontaneously pass through the opening to cause an endothermic reaction or an exothermic reaction between the first material and the second material to create a second heat sink thermal operating range different from the first heat sink thermal operating range. Embodiments also include a system and method of dual-mode passive thermal management.

Abstract: Embodiments include a heat sink cell comprising a first reservoir having a first volume of space and a first material stored in the first volume of space. The first material provides a first heat sink thermal operating range for the transfer of heat. The cell comprises a second reservoir and a second material stored in the second reservoir. A shape memory alloy (SMA) closes an opening of the second reservoir. The SMA is responsive to a temperature change of the first material or external sources to automatically open the opening so that the first material or the second material spontaneously pass through the opening to cause an endothermic reaction or an exothermic reaction between the first material and the second material to create a second heat sink thermal operating range different from the first heat sink thermal operating range. Embodiments also include a system and method of dual-mode passive thermal management.