2018 Volume 59 Issue 1 Pages 129-135
A unimorph 2-layer (PU:LaNi5/Ti) actuator consisting of a driving composite sheet with large expansion of polyurethane (PU) dispersed with powder mixture of hydrogen storage alloy of 35 vol%-LaNi5 and Pd-Al2O3 catalyst prepared by solution cast method, and a 5 μm thick Ti sheet exhibited reversible and giant rapid bending motion when subjected to hydrogen atmosphere. Reversible motion was achieved below 0.20 MPa-H2 pressure where maximum strain (εmax) values on vertical and horizontal directions were more than 2400 and 1800 ppm, respectively about 1.6 times larger than that reported (1520 and 1120 ppm) for the same actuator PU:LaNi5/Cu with 10 μm thick copper (Cu) sheet. Moreover, the maximum responsiveness (dε/dt)max by hydrogenation of cyclic motion of the PU:LaNi5/Ti was higher than that of the PU:LaNi5/Cu. The increased (dε/dt)max values mostly corresponded to decreasing elastic load resistivity (dF/dε). These were due to Ti having higher stiffness and strength than Cu allowing thinner 5 μm sheet. Caution for safety is advised since values presented herein may be different when applying the actuator to zero gravity environments.