title: Self-regenerating and hybrid irreversible/reversible PDMS microfluidic devices.
abstract: This paper outlines a straightforward, fast, and low-cost method to fabricate polydimethylsiloxane (PDMS) chips. Termed sandwich bonding (SWB), this method requires only a laboratory oven. Initially, SWB relies on the reversible bonding of a coverslip over PDMS channels. The coverslip is smaller than the substrate, leaving a border around the substrate exposed. Subsequently, a liquid composed of PDMS monomers and a curing agent is poured onto the structure. Finally, the cover is cured. We focused on PDMS/glass chips because of their key advantages in microfluidics. Despite its simplicity, this method created high-performance microfluidic channels. Such structures featured self-regeneration after leakages and hybrid irreversible/reversible behavior. The reversible nature was achieved by removing the cover of PDMS with acetone. Thus, the PDMS substrate and glass coverslip could be detached for reuse. These abilities are essential in the stages of research and development. Additionally, SWB avoids the use of surface oxidation, half-cured PDMS as an adhesive, and surface chemical modification. As a consequence, SWB allows surface modifications before the bonding, a long time for alignment, the enclosure of sub-micron channels, and the prototyping of hybrid devices. Here, the technique was successfully applied to bond PDMS to Au and Al.
authors.affiliation: Laboratório de Microfabricação, Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, São Paulo 13083-970, Brasil.
authors.forename: Letícia S
authors.initials: LS
authors.lastname: Shiroma
authors.affiliation: Laboratório de Microfabricação, Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, São Paulo 13083-970, Brasil.
authors.forename: Maria H O
authors.initials: MH
authors.lastname: Piazzetta
authors.affiliation: Instituto de Química, Universidade Federal de Goiás, Goiânia, Goiás 74001-970, Brasil.
authors.forename: Gerson F
authors.initials: GF
authors.lastname: Duarte-Junior
authors.affiliation: Instituto de Química, Universidade Federal de Goiás, Goiânia, Goiás 74001-970, Brasil.
authors.forename: Wendell K T
authors.initials: WK
authors.lastname: Coltro
authors.affiliation: Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, São Paulo 13566-590, Brasil.
authors.forename: Emanuel
authors.initials: E
authors.lastname: Carrilho
authors.affiliation: Laboratório de Microfabricação, Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, São Paulo 13083-970, Brasil.
authors.forename: Angelo L
authors.initials: AL
authors.lastname: Gobbi
authors.affiliation: Laboratório de Microfabricação, Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, São Paulo 13083-970, Brasil.
authors.forename: Renato S
authors.initials: RS
authors.lastname: Lima