Flexible and cracked polymer membrane for thermal-expansive reversible fuses using three-dimensional groove patterns

Abstract

In this study, a novel, facile, and cost-efficient manufacturing process for thermal-expansive reversible fuse (TRF) was demonstrated by using a cracked conductive layer on a flexible polymer with three-dimensional (3D) groove patterns. The current cut-off mechanism was demonstrated by the actuation of a thin membrane with a conductive layer of the TRF fabricated by a 3D-patterned mold and flexible polymer. When external heat was induced, the membrane of the TRF swelled, and the platinum-coated conductive layer was stretched, resulting in a current cut-off. In contrast, the membrane shrank, and the TRF was reconnected when the heat source was removed. The major cracks parallel to the 3D-printed patterns and minor cracks across the patterns were analyzed through the scanning electron microscope images. In addition, TRFs with pattern intervals of 250 µm (low resolution) and 100 µm (high resolution) were characterized by observing the current signal and expansion thickness of the membrane simultaneously to analyze the effect of actuation on the cut-off tendency. Finally, by applying the repetitive temperature profile between 35 °C and the cut-off temperature, the reversible performance of the TRFs was demonstrated by the cut-off and reconnection processes. These results can be applied to passive cooling systems of electronic devices to prevent overheating, which can affect the performance and durability of the device.