On-chip syringe pumps for picoliter-scale liquid manipulation.

On-chip microsyringes are developed by integrating parallel micro actuators and a microfluidic chip. Sliders of an Electrostatically Controlled Linear Inchworm Actuator (ECLIA) are applied to manipulate microsyringes in the nanometer range, which allows liquid control on the picoliter scale. ECLIA drives sliders in parallel with high accuracy and a large stroke. The requirements for syringe performance, such as parallel and precise liquid control, can be satisfied by the above features of ECLIA. A total volume of a few microL is manipulated at a flow rate of 19-27 pL s(-1) by the stepwise motion of ECLIA sliders in a fluidic channel. Microsyringes integrated into the driving mechanism are a key component of Micro Total Analysis Systems (microTAS) due to the possibility of on-chip integration. In addition, the proposed approach has a significant implication in MEMS in that the electrostatic micro actuator performs a physical task that affects the outside structure.