SMA-Film Based Elastocaloric Cooling for Small Scale ApplicationsMonday (17.06.2019) 15:30 - 15:45
This work presents the state of the art in film-based elastocaloric cooling and points out recent developments. Current cooling technologies, namely vapor compression and thermoelectric cooling, both include major disadvantages as the refrigerants in vapor compression cycles contribute to global warming and Peltier elements are restricted to low efficiencies, respectively. Elastocaloric cooling is a promising new technology with the potential to provide efficient and environmentally friendly cooling. Concepts using superelastic shape memory alloy (SMA) films with high surface-to-volume ratio are especially interesting for small scale applications like electronic chip cooling or biomedical applications. State of the art demonstrators are based on single free standing TiNiCuCo films with a thickness of 30 µm showing ultra-low fatigue properties  and rapid heat transfer due to large surface-to-volume ratio . In film-based cooling devices mechanical loading/unloading and the separation of heating and cooling power are achieved by periodically changing mechanical contact of the SMA film to solid heat sink and source elements. Single SMA film-based demonstrators reach temperature spans of 14 K and high specific cooling power of up to 18 Wg-1 . Advanced systems with cascaded design of several thermally interconnected film-based cooling units allow for higher temperature span and cooling power, thus broadening the scope of cooling applications.
 C. Chluba, H. Ossmer, C. Zamponi, M. Kohl, and E. Quandt, “Ultra-Low Fatigue Quaternary TiNi-Based Films for Elastocaloric Cooling,” Shape Memory and Superelasticity, vol. 2, no. 1, pp. 95–103, Mar. 2016.
 F. Bruederlin, L. Bumke, C. Chluba, H. Ossmer, E. Quandt, and M. Kohl, “Elastocaloric Cooling on the Miniature Scale: A Review on Materials and Device Engineering,” Energy Technology, vol. 6, no. 8, pp. 1588–1604, Aug. 2018.