Dry spinning polymeric nano/microfiber arrays using glass micropipettes with controlled porosities and fiber diameters

We present a method for dry spinning polymeric nano/microfiber arrays. In this technique polymer solution is continuously ejected from a stationary glass micropipette and the fibers are deposited as continuous arrays in parallel and complex geometrical configurations on a rotating substrate mounted on to a translation stage. As the polymer solution exits the glass micropipette, ambient air is used to evaporate the solvent, thus solidifying the fiber which is then deposited on the rotating substrate. For a given polymer, altering the processing and material parameters allows depositing fiber arrays with highly tunable porosities and uniform fiber diameters. The fiber array porosity is observed to decrease with increasing angular velocity of the rotating substrate at a constant translational stage velocity. Fiber array breaking strength experiments as a function of porosity show higher loads required to break low porosity arrays, which is critical in designing stronger materials. Additionally, single and double layered biological scaffolds fabricated using this technique are seeded with mouse C2C12 cells and cellular dynamics of adhesion, migration and proliferation is investigated.