Shape memory behavior of TiNi alloy films sputter-deposited on polyimide substrate

We developed an RF magnetron sputtering system equipped with separate sources as well as with a heating and ion-irradiating system for substrates. Without using the ion-irradiating system for substrates, the films deposited on ambient-temperature substrate have been amorphous. However, we find that crystallized film is deposited even at 353 K of substrate temperature with simultaneous ion irradiation. Shape memory effect of the crystallized film which was-deposited on a polyimide sheet of 0.025 mm in thickness was observed. The film deposited on a polyimide sheet was cut into the shape of a double-beam cantilever and the ends of the two beams were connected to an electrical power supply. The double-beam shows a two-way motion by turning on and off at room temperature. These results are expected to find use in extensive applications as a convenient small actuator. (C) 2012 Elsevier B.V. All rights reserved.