Characterization of a Micropump Actuated by Ternary TiNiCu Shape Memory Thin Films

Thin film SMAs have the potential to became a primary actuating mechanism for micropumps. In this study, a micropump driven by TiNiCu shape memory thin film is designed and fabricated. The micropump is composed of a TiNiCu/Si bimorph driving membrane, a pump chamber and two inlet and outlet check valves. The thickness, surface morphology and phase transformation property of TiNiCu film have been characterized by scanning electron microscope (SEM), atomic force microscopy (AFM), differential scanning calorimeters (DSC). Driving capacity of TiNiCu/Si biomorphic driving membrane has been investigated. The film surface shows a smooth and featureless morphology without any cracks, and the hysteresis width ΔT of TiNiCu film is about 10 °C. By using the recoverable force of TiNiCu thin film, the actuation diaphragm realizes reciprocating motion effectively. Experimental results show that the micropump driving by TiNiCu film has good performance, such as high working frequency, stable driving capacity, and long fatigue life time.