FEP/PFA films for chemically-inert microfluidic valves and
pumps We present a simple method for fabricating chemically-inert Teflon
microfluidic valves and pumps in glass microfluidic devices. These
structures are modeled after monolithic membrane valves and pumps
that utilize a featureless polydimethylsiloxane (PDMS) membrane
bonded between two etched glass wafers. The limited chemical
compatibility of PDMS has necessitated research into alternative
materials for microfluidic devices. Previous work has shown that
spin-coated amorphous fluoropolymers and Teflon-fluoropolymer
laminates can be fabricated and substituted for PDMS in monolithic
membrane valves and pumps for space flight applications. However,
the complex process for fabricating these spin-coated Teflon films
and laminates may preclude their use in many research and
manufacturing contexts. As an alternative, we show that
commercially-available fluorinated ethylene-propylene (FEP) Teflon
films can be used to fabricate chemically-inert monolithic membrane
valves and pumps in glass microfluidic devices. The FEP Teflon
valves and pumps presented here are simple to fabricate, function
similarly to their PDMS counterparts, maintain their performance
over extended use, and are resistant to virtually all chemicals.
These structures should facilitate lab-on-a-chip research involving
a vast array of chemistries that are incompatible with native PDMS
microfluidic devices. |