OpenEnvironment MicroDevice forIntegration ofPatchClampInstrumentation withTargeted Microfluidic Chemical Delivery

We describe a technique forthefabrication anduse ofa microfluidic flowdevice thathasportions that are open totheexternal environment. Matching inlet andoutlet flowrates inthedevice formsvirtual walls through surface ten- sionattheliquid-air interface. Traditional instrumentation, suchasthepatch-clamp pipette, can beintroduced into theflow streamthrough thesurface-tension walls, thereby combining decades ofelectrophysiology techniques withthebenefits ofmi- crofluidic environmental control ofin-vitro tissue samples such asneural cultures andbrain slices.