Development of a Modular Peristaltic Microfluidic Pump and Valve System 1/30/2007 BME 273 Group 20: Adam Dyess, Jake Hughey, Michael Moustoukas, Matt Pfister

Microfluidics Minimal reagent consumption Increased speed of reactions Study of biological phenomena at the single cell level

Current Pumps at VIIBRE Harvard Pico Plus syringe pumps $2,000 / pump Limiting complexity of microfluidic devices

Diagram of the System Nitrogen or Liquid Fluid Flow Pneumatic Valves Peristaltic Pump Christmas Tree Nanophysiometer

Pneumatic Valves Two-layer PDMS device –Flow layer –Control layer Thin PDMS membrane deflects into the flow channel when the control channel is pressurized Unger et al. 2000

4 pneumatic valves in series Control pressure psi Flow channel dimensions –100 um wide, 10 um tall (round) or 5 um tall (rectangular) Control channel –Valve area (300 um by 300 um) Current Design of Peristaltic Pump

Pump in Action

Completed Work Safety, photolithography, and microfabrication training Initial estimates of flow rates are 5 nl/min – much too low Fabricated and tested devices with flow above and control below – membrane stuck to roof of flow channel Control Flow

Current Status Will try changing “off” state of control line to vacuum Developing ways to increase flow rates – likely need at least 100 nl/min Multiphase parallel pumps are ready to be fabricated The fabrication of a second control box is about to begin

Current Work Increase cross-sectional area of flow channel Vias to switch flow channel layer Characterize flow rates –Pulse-chase with bolus of fluorescent solution –Head to head vs. syringe pump Kartalov et al Flow Groisman & Quake 2004 t = 0 t = d / v

LabVIEW Interface Design an improved interface that allows for input of pump sequences - possibly using Excel Controls will include valve on/off, rate, time, and schedule

Future Work Tesla valves or microfluidic rectifiers for anisotropic flow resistance Pumps at either end of device for push/pull Long-term testing of mechanical stability of pumps Sylgard 186 for mechanical properties instead of Sylgard 184 Bardell 2000 Groisman & Quake 2004