Effect of thermal treatment on the chemical resistance of polydimethylsiloxane for microfluidic devices

We investigated the use of thermally treated polydimethylsiloxane (PDMS) for chemically-resistant microchannels. When the PDMS underwent the thermal treatment at 300 degrees C, swelling was reduced and the surface of the PDMS microfluidic channel endured well in the extracting media such as dichloromethane. Furthermore, despite the small decrease in size after thermal treatment, both the channel shape and transparency were maintained without showing fluid leakage. The thermally treated PDMS had more hydrophilic properties compared to the untreated PDMS. A single step post-casting process described in this work does not require complex chemical treatments or introduction of foreign materials to the host PDMS substrate, thus expanding the application area of PDMS-based microfluidics.