Proton Beam Writing on Chitosan Films for Bionanomedicine and Microfluidics: Pilot Experiments

Proton-beam writing is a high-resolution lithographic technology that can be used to fabricate 3D micro- and nanostructures for various applications. In particular, the method is suitable for creating 3D matrices for cell growth and development. However, mainly polymethylmethacrylate and inorganic silicon polymers are used as resists for such lithographs. At the same time, it is interesting to use biological polymers as a substrate, which has already proven themselves well in medical and biological applications. Chitosan is a naturally occurring polymer that finds its application in various industrial and biomedical fields. Recently, it has become a promising material for biological functionalization of microelectromechanical systems, for creating laboratories on a chip. In our work, we show the possibility of using chitosan films as a positive resist for proton lithography. The proton beam writing technique allows obtaining fine linear structures on the chitosan surface, with excellent quality of walls. Creating fine micro- and nanoscale structures by proton beam writhing opens new possibilities for chitosan-based materials.