Patent ID: 8173078

Claim:
A gravity-driven micropump for employing in a microfluidic chip, said gravity-driven micropump comprising: at least one air inlet channel; at least one reactant chamber for storing a reactant, said reactant chamber having a top end connected to said air inlet channel; a reaction chamber having a top end connected to a bottom end of said reactant chamber; a waste fluid chamber having a top end connected to a bottom end of said reaction chamber; a pressure-control channel containing a pressure-control fluid inside a section between a first end and a second end of said pressure-control channel for controlling pressure in said pressure-control channel, said pressure-control fluid flowing from said section towards said second end by gravity force when said micropump is oriented by a user to position said first end higher than said second end; and a connection channel having a first end connected to a bottom end of said waste fluid chamber and a second end linked to said first end of said pressure-control channel; wherein when said pressure-control fluid flows towards said second end of said pressure-control channel, a negative pressure is created inside said connection channel, said waste fluid chamber and said reaction chamber to drive said reactant from said reactant chamber to flow through said reaction chamber into said waste fluid chamber.