Characterization and modeling of direct-write fabrication of microscale polymer fibers

A new direct-write system for fabricating suspended microscale and sub-microscale polymer fibers has been developed and characterized. This system is capable of generating arrays of precisely-positioned fibers with controllable diameters in three-dimensional space. The driving mechanism behind this process harnesses the surface tension of liquid bridges to promote the controlled thinning of a macroscale polymer solution filament into the desired micro- or sub-microscale fiber. The correlation between fiber diameter and several experimental parameters including solution concentration, drawing rate, and fiber length was characterized using a series of viscous poly(methyl methacrylate) (PMMA) solutions. A dimensional analysis of the physics of the fiber drawing process was used to adapt this data into an empirical relationship describing fiber formation from a generalized polymer solution. This information was subsequently utilized to predict fiber diameter from several other non-PMMA-based polymer solutions with accuracy comparable to the intrinsic variation of the process itself, thereby eliminating the need to perform lengthy characterizations on new polymer solutions.