Two-Way Shape Memory Effect of a Shape Memory Composite Strip

In this work, a NiTi shape memory alloy (SMA) wire was embedded into a rubber/shape memory polymer (SMP) soft matrix to form a composite strip with a two-way reversible bending behavior. First, the elastic moduli of SMA wire were characterized as increasing about 3 times (18.6 GPa at martensite phase and 50.1 GPa at austenite phase) from 25 °C to 90 °C. Then, an SMA composite strip using SMP to replace the rubber matrix was fabricated to significantly improve the load-bearing ability (16-fold) at 28 °C. After that, the good two-way bending behaviors of the rubber/SMP-based SMA strip with high shape deploying ratio above 80% were demonstrated. Finally, the application of rubber/SMP-based composite strips in a space-deployable antenna model with two-way reversible bending behavior was developed and demonstrated through a heating and cooling temperature cycle.