Strain-induced crystallization and elastocaloric response in SLS-printed thermoplastic polyurethane

In this work, we investigate the elastocaloric performance (eCE) of thermoplastic polyurethane (TPU) processed via Selective Laser Sintering (SLS), an additive manufacturing technique with significant yet underexplored potential in this field. A comprehensive experimental methodology was developed, which combines mechanical testing of V-notched specimens, infrared thermography, and in situ SAXS/WAXS analysis to simultaneously track mechanical, thermal, and structural evolution under cyclic loading. The experimental results reveal reversible adiabatic temperature changes of up to 5 °C, associated with strain-induced crystallization (SIC) and directional structural orientation. The use of a localized notched geometry (V-notched) enhanced the elastocaloric response at moderate global strains. Numerical modeling further confirmed the development of stress states favorable for SIC. These findings validate the elastocaloric functionality of SLS-printed TPU and offer new insights into processing–structure–property relationships. This work represents a step forward in the development of scalable, environmentally friendly cooling devices based on polymeric materials.