Hydraulic microactuator with coarse/fine drive-switching mechanism

Abstract

For precise physical and chemical analyses of cells in microfluidic devices, they should be located near the sensors on a microchannel wall. To transport cells close to the sensors precisely, a hydraulic microactuator with a coarse/fine drive-switching mechanism was developed. The microactuator has a movable thin film with micropillars, and switches drive modes through the contacts of the micropillars into a microchannel wall. A coarse approach and a fine adjustment of the position of cells on the thin film toward the microchannel wall by switching the drive modes was achieved in the microactuator. The displacement of the microactuator was measured at 1 µm resolution using the focus degrees obtained using the two-dimensional fast Fourier transformed images. The displacement ratio of the coarse to fine drive mode achieved using the microactuator was 13.9. Using the microactuator, cyanobacteria were introduced into the device and were transported 53 µm from the bottom to the top of the microchannel in the coarse drive mode, and the position of the cyanobacteria was precisely adjusted near the microchannel wall in the fine drive mode.