open access publication

Article, 2023

Additive manufactured thermoplastic elastomers for low-stress driven elastocaloric cooling

In: Applied Materials Today, ISSN 2352-9415, 2352-9407, Volume 30, Page 101711, 10.1016/j.apmt.2022.101711

Contributors (3)

Wang, Kun (Corresponding author) [1] Engelbrecht, Kurt Luther (0000-0002-3713-9415) [1] Bahl, Christian Robert Haffenden (0000-0002-1153-7183) [1]

Affiliations

  1. [1] Technical University of Denmark
  2. [NORA names: DTU Technical University of Denmark; University; Denmark; Europe, EU; Nordic; OECD]

Abstract

Exploiting the strain-induced crystallization of soft elastomeric polymers elastocaloric cooling has recently been explored as an environmental-friendly alternative to conventional refrigeration. Elastomers require a much lower applied stress to induce the elastocaloric effect compared to shape memory alloys. Several prototype coolers employing these soft polymers have been demonstrated to achieve a moderate temperature span under lower stresses. Here, we investigate the elastocaloric properties and potential cooling performance of five thermoplastic elastomers that can be 3D printed, both in the form of filaments and as Additive Manufactured (AM) parts. The materials were first characterized as filaments to screen for the elastomers with the highest elastocaloric effects. A large adiabatic temperature change of 17.8 K was obtained in the Ultimaker98A filament. AM parameters were optimized to achieve parts with satisfactory functional stability while maintaining their elastocaloric effect. As a printed part, NinjaFlex achieved a high material coefficient of performance (COPmat) of 3.2 with 1.74 J/g input work at ∼0.1 Hz, driven by a stress of 5.7 MPa. Implementing AM elastocaloric elastomers creates opportunities for the development of full-scale low-activation-stress regenerative elastocaloric cooling components that enable optimizing flow structures and enhanced heat-transfer performance.

Keywords

AM parameters, Additive Manufactured Parts, Hz, MPa, NinjaFlex, adiabatic temperature change, alloy, alternative, applied stress, changes, coefficient, components, conventional refrigeration, cooler, cooling, crystallization, development, effect, elastocaloric, elastocaloric cooling, elastocaloric effect, elastocaloric properties, elastomers, environmental friendly alternative, filaments, flow structure, form, form of filaments, functional stability, heat transfer performance, input work, large adiabatic temperature change, low applied stress, low stress, manufactured parts, material coefficients, materials, memory alloy, opportunities, parameters, part, performance, polymers, properties, prototype cooler, refrigeration, screen, shape memory alloy, soft polymers, span, stability, strain-induced crystallization, stress, structure, temperature changes, temperature span, thermoplastic elastomers, work

Funders

  • China Scholarship Council