Magnetic handling of droplet in micro chemical analysis system utilizing surface tension and wettability

Abstract

We propose a droplet handling mechanism for micro-chemical analysis systems. We enabled reliable magnetic droplet handling without sample beads sticking to the glass surface by using different liquids' wettability and surface tension. We also developed a separation- and fusion-mechanism of droplets containing beads, and confirmed that our device can effectively condense and rinse the beads by combining the proposed separation and fusion units. The volume of separated droplets containing beads was 30 nl, and we were able to rinse the beads in a series of separation and fusion operations by freshly rinsing droplets 1600 times using the fusion of fresh droplet. The primary advantage of the system is that it doesn't need mechanical devices such as a pump, a valve, and a filter, for handling the solution.