Abstract
Electroosmotic flow is applied to form a denaturing gradient on a microchip. Quick measurement of electroosmotic flow velocity on site is required for precise process control. Proposed method is applied to the microchannel with a Y-shaped junction. High voltage signals are applied to the two wells upstream of the junction and the downstream well is grounded. A neutral dye is added to one of the upstream wells. Under the condition of constant sum of two high voltage signals, two voltage signals are fluctuated in a square waveform with known frequency. From the image analysis of the flow with propagating cyclic disturbance of a dye, the flow velocity can be calculated easily.
