TMT: Thermal Management Technologies

DARPA’s portfolio of Thermal Management Technologies, which are key enablers of high-power military systems, centers on the exploration and optimization of new nanostructured materials for two-phase heat spreaders, air-cooled exchangers, and thermal interface materials.

Significant enhancements in fundamental device materials, technologies and system integration have led to rapid increases in the total power consumption of DoD systems. In many cases, power consumption has increased while system size has decreased, leading to an even greater problem with heat density. Thermal management of DoD systems often imposes the main obstacle to further enhancements.

The overarching goal of the DARPA Thermal Management Technologies (TMT) Program is to explore and optimize new nanostructured materials and other recent advances for use in thermal management systems. The program is divided into five technical efforts:

• TMT: Thermal Ground Plane (TGP)
• TMT: Microtechnologies for Air-Cooled Exchangers (MACE)
• TMT: NanoThermal Interfaces (NTI)
• TMT: Active Cooling Modules (ACM)
• TMT: Near Junction Thermal Transport (NJTT)

The TGP effort is focused on high-performance heat spreaders which use two-phase cooling to replace the copper alloy spreaders in conventional systems. 

The goal of the MACE effort is to enhance air-cooled exchangers by reducing the thermal resistance through the heat sink to the ambient, increasing convection through the system, improving heat sink fin thermal conductivity, optimizing and/or redesigning the complimentary heat sink blower, and increasing the overall system (heat sink and blower) coefficient of performance.

 The NTI effort is focused on novel materials and structures that can provide significant reductions in the thermal resistance of the thermal interface layer between the backside of an electronic device and the next layer of the package, which might be a spreader or a heatsink. 

ACM will investigate active cooling of electronic devices using techniques such as thermoelectric coolers, sterling engines, etc. 

The goal of the Near Junction Thermal Transport (NJTT) effort of the TMT program is to achieve a 3x or greater improvement in power handling from GaN power amplifiers through improved thermal management of the near junction region.

Collectively, research in these areas will improve thermal resistance barriers at all layers of all DoD systems. At the completion of these efforts, targeted insertions of specific TMT structures into DoD platforms will lead to further developments.