High-speed composite microactuator based on Ti$_{2}$NiCu alloy with shape memory effect

Samples of microactuators are made of a bimorph composite of Ti$_{2}$NiCu alloy with a thermoelastic martensitic transition and the shape memory effect, and their response rate is investigated. The active layer of the composite actuator is a layer of the rapidly quenched Ti$_{2}$NiCu alloy, pseudoplastically prestretched, and an amorphous layer of the same alloy is used as an elastic layer. Typical sizes of the microactuator are 30 $\times$ 2 $\times$ 2 $\mu$m. The controlled amplitude of the displacement of the microactuator tip is approximately 1 $\mu$m. The response rate of the microactuator was investigated by scanning electron microscopy. Activation of the microactuator was achieved by heating when electric pulses were passed through it. Full activation of the microactuator at frequencies up to 1 kHz was demonstrated; partial activation was observed at frequencies up to 8 kHz. The possibility of operating the device in a self-oscillating mode at frequencies of the order of 100 kHz is demonstrated.