A novel PDMS-based microfeature-size fabrication method for biocompatible and flexible devices

In this article, a novel cost-effective method is proposed to achieve microfeature-sized patterns on Polydimethylsiloxane (PDMS) substrates. PDMS as a biocompatible, flexible, economical, and easy-to-use polymer benefiting the trait of mechanical impedance close to soft tissues, is the best candidate to be used where we need communication between the electrical circuit and soft tissues. This is while PDMS can be matched with tissue’s different shapes and doesn’t cause any trauma. Complex and high-cost manufacturing methods of microfeature-sized patterns on PDMS, such as conventional microfabrication methods will be eliminated by the proposed approach. Our technique takes advantage of not requiring standard photolithography processes, making it simple and cost-effective. This manner can be used for a variety of different purposes, such as microfluidic chip fabrication, biosensing applications, neuroscience research and neural prosthetics such as electrocorticogram (ECoG) and, in general, where microfeature-size patterning on PDMS is required. To prove the method’s functionality, a test sample was fabricated. Firstly, the scaffold was fabricated using a conventional laser engraver and Poly(methylmethacrylate) (PMMA). Then, a mold was made using this scaffold from PDMS. Then S1813 photoresist was applied as an anti-adhesion layer between the PDMS mold and the sample to make the sample peel off easily from the mold surface. The final sample indicated that the pattern’s feature size was around 250 micrometers and that the required patterns were very close to the desired form possible.