Scientists Created Shape-Memory Films That Will Transform Chip Thermal Management

Japanese and German scientists have introduced a new elastocaloric cooling system that requires no traditional bulky compressors or electric drives. Researchers from the University of Tsukuba and the Karlsruhe Institute of Technology forced the system to trigger a cooling cycle directly from an external heat source.

How Shape-Memory Alloys Replaced the Compressor 

The development relies on the use of two ultra-thin metal films:

• Actuator (22 µm, TiNi): Contracts when heated, converting thermal energy into mechanical movement.
• Refrigerant (26.5 µm, TiNiFe): Stretches under the force of the first film, triggering a phase transition in the crystal lattice and absorbing heat.

The TiNi thermal actuator demonstrated an impressive force-to-displacement ratio of 14.5 N/mm compared to 1.1 N/mm in conventional electromechanical alternatives. In laboratory tests, direct heating of the system from a 130 °C source provided a cooling power of 3.32 W/g with a temperature difference of 2.2 K.

How Can It Help Microelectronics

The main value of this technology lies in its potential ability to utilize processor waste heat for self-cooling. For now, the prototype's power output is only 2.09 mW, which is insufficient for modern silicon crystals, and the system requires cyclic heating as well as faster response times.

Scientists are currently working on connecting multiple films to scale up the active material and increase efficiency.