High Pressure On-Chip Valves for Thermoplastic Microfluidics

A high-pressure microvalve technology based on the integration of discrete elastomeric elements into rigid thermoplastic chips is described. The low-dead-volume valves employ deformable polydimethylsiloxane (PDMS) plugs actuated using a threaded stainless steel needle, allowing exceptionally high pressure resistance to be achieved. The simple fabrication process is made possible through the use of poly(ethylene glycol) (PEG) as a removable blocking material to avoid contamination of PDMS within the flow channel while yielding a smooth contact surface with the PDMS valve surface. Burst pressure tests reveal that the valves can withstand over 24MPa without leakage.