One-step modification and structuring of PDMS surfaces and its application in the bench-top Fabrication of self-driven microfluidic channels

This work describes a one-step method for the chemical modification of polydimethylsiloxane (PDMS) surfaces. Thin films of ionic and non-ionic surfactants were patterned into an array format, transferred onto silicone pre-polymers, and subsequently immobilized onto the PDMS surfaces during vulcanization. Our results show that while all surfactants tested can render PDMS surfaces hydrophilic through the in-mould modification process, only those modified with silicone-based block copolymer surfactants were stable over two wetting cycles. The modification approach was further used to fabricate microfluidic devices that exhibited steady capillary flow rates, tuneable by the device geometry.