Deployment performance of shape memory polymer composite hinges at low temperature

Abstract

Shape memory polymer composite hinges, adapted for possible space applications, were successfully designed and fabricated, and performance tests at room temperature confirmed their full recoverability in our previous studies. Since shape memory polymer composite hinges are intended for space applications, they should be able to operate at low temperature. Even though the deployment of the hinge at room temperature triggered by the stimulation of a heating element has been quite promising, a suitable design for a shape memory polymer composite hinge with a heating element is more important at low temperatures because shape memory polymer composite hinges lose much heat to the environment. The recoverability of shape memory polymer composite hinges and the impact of the heating element design on the deployment time at low temperature are brought to light in this article. A shape memory polymer composite hinge with an attached heating element was fabricated as in our previous studies. The necessary power and supply power for deployment of the shape memory polymer composite hinge at a low temperature of –10°C were calculated, and a finite element analysis for the heating process was performed with the supply power. A folding and deployment test of the shape memory polymer composite hinge at –10°C was performed to show its shape recoverability. However, the shape memory polymer composite hinge did not deploy to its original shape. To determine the reason, measurements of temperature distribution were done using an infrared camera and thermocouples. The results revealed that the low temperature along the two side edges of the shape memory polymer composite tape prevented full deployment of the shape memory polymer composite hinge, which also revealed the need for design modification. The folding and deployment test of our modified shape memory polymer composite hinge demonstrated a nearly full deployment.