An Experimental Study of a Polymer Pulsating Heat Pipe 3D-Printed on a Thin Polymer Sheet

A polymer pulsating heat pipe (PHP) was 3D-printed on a thin polymer sheet to reduce the thermal resistance of the PHP wall at heated and cooled sections. Three kinds of polymer sheets were selected: one 0.21-mm-thick acrylonitrile butadiene styrene (ABS) sheet and two 0.12-mm-thick and 0.25-mm-thick polycarbonate (PC) sheets. A serpentine channel of the PHP designed using a 3D CAD program was printed directly onto these polymer sheets. A semitransparent ABS filament was used as the 3D printing material. Experiments were conducted under the bottom-heat mode to evaluate the operational characteristics and thermal performance of the PHP. Hydrofluoroether-7100 was used as the working fluid, and its filling ratio was 50% of the total inner volume of the serpentine channel. From the experimental results, steady-state heat transport was confirmed for all the PHPs fabricated in this study. The effectiveness of the thin polymer sheets used for the PHP wall was also confirmed. The value of 432 W/(m∙K) was obtained as the maximum effective thermal conductivity for the PHP using the 0.12-mm-thick PC sheet when the heat transfer rate was 16.8 W.