Patent ID: 8246805

Claim:
A micro-fluidic chip comprising: a hollow area into which a charged droplet is introduced; and an electrode configured to be provided toward the hollow area; wherein movement direction of a droplet in the hollow area is controlled based on electric force acting between a charge given to the droplet and the electrode; a plurality of branch areas configured to communicate with the hollow area; wherein the droplet is led to one branch area that is arbitrarily selected by controlling the movement direction of the droplet in the hollow area; a flow channel configured to send a liquid into the hollow area; and a fluid inlet configured to meet the flow channel at least from one side of the flow channel and introduce a fluid that is a gas or an insulating liquid into the flow channel; wherein a liquid passing through the flow channel is segmented to be turned to a droplet by a fluid introduced from the fluid inlet and is sent into the hollow area; a microtube configured to introduce a first liquid into a laminar flow of a second liquid passing through the flow channel; wherein the first liquid and the second liquid are sent to the communicating port of the flow channel or a confluence of the fluid inlet in such a way that a laminar flow of the first liquid introduced from the microtube is surrounded by the laminar flow of the second liquid; the flow channel has a narrowing part that is so formed that area of a section of the narrowing part perpendicular to liquid sending direction gradually decreases; and the first liquid and the second liquid are so sent that laminar flow widths of the laminar flows of the first liquid and the second liquid are narrowed in the narrowing part.