Abstract
In this paper, we propose innovative liquid pumping devices for μTAS. In this system, microchannels were fabricated in silicon substrates of silicon on insulator(SOI). The vibrating wall was composed of piezoelectric PZT thin films deposited on the Si device layer of the microchannel. The active microchannel can transport liquid by traveling wave induced on the surface of the piezoelectric vibrating channel by applying sinusoidal voltages to each patterned top electrodes with different phase. The active microchannel of 200μm wide was fabricated by the deep reactive ion etching(DRIE) process. The displacement profiles of the vibrating wall and frequency response were measured by a laser Doppler vibrometer. Maximum displacement was about 50nm at the applied voltage of 1kHz and 20Vpp. Mean flow velocity of about 16μm/s at primary resonance point of 573kHz and 32μm/s at secondary resonance point of 859kHz were achieved at 20Vpp. Because of the simple structure without valves and diffuser, it is suitable for the integration into μTAS devices.
