Integration of polydimethylsiloxane membranes in SU-8 structures

A fabrication process to integrate polydimethylsiloxane (PDMS) in SU-8 structures is reported as an inexpensive alternative to reversible bonding. The integration lies in fabricating clamped PDMS membranes inside SU-8 structures. These PDMS-SU-8 structures include the advantages of both materials when necessary, that is, the flexibility of the PDMS in membranes and the rigidity of the SU-8 in rigid parts. The validity of the fabrication process is demonstrated by showing the behaviour of sample structures. The mechanical unions in these samples are tested for tightness and resistance to pressure, withstanding up to 1000 mbar. The process is especially suitable for microfluidic applications.