Polymerized Poly(ethylene glycol) Diacrylate Microfluidic Membrane Valves
Polymerized poly(ethylene glycol) diacrylate (poly-PEGDA) was fabricated into pneumatically controlled, non-elastomeric membrane valves as a nonspecific adsorption resistant alternative to polydimethylsiloxane valves. Temporal response, valve closure, and long-term durability of these poly-PEGDA valves were evaluated. Valve operation up to 8 Hz was achieved with a ~100 ms opening time (without applied vacuum) and a ~20 ms closure time. Valve closure demonstrates less leakage in geometries with a larger membrane contact area (>0.3 mm[sup]2[/sup]) and pedestals wider than 15 [gm/]m. After ~1000 actuations to reconfigure polymer chains and increase membrane elasticity, the fluid pressure needed to open a closed valve becomes the same as the applied control pressure. After this initial conditioning, the poly-PEGDA valves maintain a linear relationship between the closure pressure and the opening pressure required to initiate flow even after 115,000 actuations. These robust valves have potential for application as peristaltic pumps and in small volume bioassays or impedance detection.