Droplets Handling Device Generating Droplets Using Air/Water Two-Phase Flow

摘要

Recently, micro total analysis system (μ-TAS) utilizing micro-reactors is widely studied. Transportation of micro/nano objects is crucial in μ-TAS. Utilizing droplets nano liters in volume as the conveyance media is one of the most attracting methods. Generation and positioning of size-controlled droplets are two crucial technologies. This paper proposes a micro-fluidic device that generates droplets utilizing air-water two-phase flow and sequentially, places them at designated regions by exploiting the spatial differences in surface energies of the channel walls, which are created by self-assembled-monolayer (SAM). First, we fabricated a T-channel device functioned by octadecyltrichlorosilane (OTS) in a stripe shape. This device can be manufactured at very low cost and thus be disposable. We obtain experimental result which is controlling droplets volume. We successfully generate and position multiple droplets. Note that both droplets generation and positioning processes are operated only pneumatically. We demonstrate transportation of fluorescent micro-particles using the fabricated devices. The particles were introduced into the water and the droplets generation and positioning procedures were conducted.