Fabrication and Functionalization of 3D Printed Polydimethylsiloxane-Based Microfluidic Devices Obtained through Digital Light Processing

This work reports the preparation and 3D printing of a custom-made photopolymer based on acrylate-polydimethylsiloxane (PDMS), for the fabrication of complex-shaped 3D printed microfluidic chips. By selecting and combining the proper materials during the preparation of the resins along with the freedom of design of light-based 3D printers, 3D microfluidic PDMS-like chips are obtained with excellent optical features, high chemical stability, and good mechanical properties. Furthermore, taking advantage of unreacted functional groups exposed on the sample's surface after the 3D printing step, the surface properties of the devices are easily and selectively modified during the postcuring step through UV-induced grafting polymerization techniques, giving an added value to the printed devices in terms of surface treatment compared to conventional methods. The 3D printing of the PDMS-based resins developed here may potentially transforms the fabrication methodology of PDMS microfluidic devices by decreasing manufacturing costs and time, allowing the production of complex-shaped and truly 3D microdevices.