Research Areas

Post-drawing (elongating) polymer fibers is a critical manufacturing process that is used in conventional fiber manufacturing process. As the fiber length increases, the fiber diameter thins and the long polymer chain molecules align along the fiber axis. This makes post-drawn fiber much stronger than unprocessed fibers. However, it is very difficult post-draw fragile, tiny electrospun nanofibers. Our groups uses a unique dual automated track collector to post-draw electropsun fibers and investigate the process-structure-property relationships. 

Mechanical dip drawing is a simple, versatile method to fabricate polymer nanofibers. However, the yield of manual dip drawing is extremely low since each fiber is pulled individually.  Our group pioneered a new "Trackspinning" approach that integrates dip drawing with automated tracks to produce polymer fibers within a continuous manufacturing system.  This approach could be used to scale up polymer fiber production for a wide variety of materials. 

Active

- NSF: PFI-TT: Commercial scale production of aligned polymer nanofiber materials and yarns (2345785)

- NSF: RUI: Laser-Zone Drawing and Annealing of High Strength Polymer Nanofibers (2110027)

- New Jersey Health Foundation: Nerve Tissue Extracellular Matrix Hydrogels with Embedded Aligned Nanofibers for Peripheral Nerve Repair (PC255-25)

Completed

- Army Research Laboratory: Thermosets for Agile Manufacturing   (W911NF-17- 2-0227) 

- NSF: CAREER: Post-Processing Polymer Nanofibers for Improved Mechanical Properties (1653329)

- NSF: RUI: Continuous Processing for Improved Properties of Nanofibers (1561966)

-  New Jersey Health Foundation:  Nanofiber-based Motion Energy Harvesters for Implanted Medical Devices    (PC34-16) 

Aligned nanofibers can provide physical guidance cues that orient regenerating axons and accelerate their regrowth. However, tiny, delicate polymer nanofibers are difficult to organize in stable 3D architectures that are ideal for peripheral nerve grafts. Our group is using additive manufacturing technologies to engineer aligned nanofiber/hydrogel composite materials where a hydrogel matrix stabilizes nanofiber architecture,  while allowing axon infiltration into the graft.  This project is a collaboration with the Vega lab at Rowan University

Zone drawing is a fiber post-drawing approach where a small segment of fiber is heated up to make it pliable. With applied tension, the heated segment will elongate and its diameter will thin. Sequential laser scanning of a fiber can post-draw across its length. Small diameter fibers heat and cool rapidly under laser scanning. Our group is exploring how this rapid heating & cooling during laser zone drawing contributes to fibers with highly aligned polymer chains and enhanced mechanical properties 

Centrifugal spinning is a high yield fabrication technique for polymer nanofiber fabrication. Our group  integrates centrifugal spinning with automated track collectors to produce highly aligned, post-drawn centrifugal spun nanofibers.

Materials made of randomly-oriented nanofibers are already commercially produced on existing roll-to-roll electrospinning equipment, mostly for filtration applications. However, heat, charge, light, fluid, and cells respond to the unidirectional orientation of aligned fibers and oriented fibers provide maximum strength in the axial direction. New technologies are being explored to make roll-to-roll manufacture of aligned nanofibers possible. 

Continuous multi-nanofiber yarns are desired for commercial applications, however currently availible technologies cannot produce yarns with desired length and mechanical strength.  New technologies are being explore to overcome limitations and produce yarn with lengths and strength suitable for nanofiber textile manufacturing.