US Patent 7302970 Liquid delivery device

A micro liquid delivery device includes a flow channel for flowing a liquid, at least two pressure-generators for generating pressures provided in the flow channel, and a variable member placed between the pressure-generators and capable of transforming between a first stable state and a second stable state by a generated pressure. A branch of the flow channel is selected by transforming the variable member into the first stable state or the second stable state. A valve for changeover of flow channel branches includes a variable member placed between a pressure-generator and transformable between a first stable state and a second stable state by a generated pressure, with the valve serving to select a branch of flow channel branches by the variable member.