Authors: D. Henderson
Affilation: New Scale Technologies, United States
Pages: 272 - 275
Keywords: microfluidics, fluid transport, PCR, drug delivery, piezoelectric, ultrasonic, pump, valve, positive displacement
Microfluidic pumping mechanisms, such as membrane micro pumps, create a pulsed stream with generally low pressure, low flow and limited precision. We present a novel piezoelectric motor that is used to create a positive displacement pump for microfluidic applications. This direct displacement pump achieves nanoliter precision and a much wider range of pressure/flow options for lab-on-a-chip applications. The millimeter-scale ceramic motor generates > 0.2 N of force over many millimeters of travel with submicrometer precision. In this patented design, a tiny screw moves with precise and highly controllable linear motion. A positive displacement pump is created by using the tip of the screw to directly move a piston, syringe or bellows. The precise movement of the screw is directly converted to fluid flow, creating a highly precise and steady flow regardless of backpressure. Pressure and flow are easily scaled by adjusting the syringe diameter. This new pumping mechanism is being investigated to improve a variety of lab-on-a-chip instruments, including the polymerase chain reaction (PCR) process for DNA analysis. We present closed-loop data for the motor including variable speeds of 1 µm/s to 5 mm/s and position resolution of 0.5µm. This data is correlated with pump performance for several design examples.