Nanofiber Yarns Fabricated
by Immersion Rotary Jet Spinning

From: Gonzalez, G.M., L.A. MacQueen, J.U. Lind, S.A. Fitzgibbons, C.O. Chantre, I. Huggler, H.M. Golecki, J.A. Goss, and K.K. Parker, "Production of synthetic, para-aramid and biopolymer nanofibers by immersion rotary jet-spinning," Macromolecular Materials and Engineering. 302 (1), (2017).

Kevin K. Parker who leads this project is a lieutenant colonel in the United States Army Reserve having served several active duty tours in Afghanistan after the September 11 attacks. Kit has been instrumental in recruiting returning veterans to this research project and to other efforts in the Harvard MRSEC as part of our Veterans student/researcher outreach initiative. Indeed, several of the authors on the recent work are returning veterans who are pursuing careers in STEM as a result of engagement of research projects such as these that have a meaningful connection to fellow active duty service personnel.

The figures show a) the funnel collection system, b) the streamlines of the vortex wrapping individual nanofibers into yarns, allowing for their manual collection, and c) nylon and PPTA nanofiber yarns that were fabricated (scale bars = 50 μm). The vortex was created by having an inlet precipitant fluid flow into and out of a funnel at a rate that created and sustained the vortex.

Nanofibers, fibers with a size less than 1/100 of a human hair, offer a wide range of benefits from improved mechanical properties to improved alignment of cells. However, due to their small size, they are difficult to handle and process. To overcome this limitation, Parker and his team at the Harvard MRSEC recently reported in Macro Mol Mat & Eng the development of a funnel collection system to fabricate nanofiber-based yarns. Nanofibers are produced by immersion Rotary Jet-spinning where a polymer solution is extruded through a small hole by rotating forces and spun into a bath. The funnel bath then pulls and threads the fibers together (a, b). Using this method, the team has demonstrated increased surface forces between the fibers, increasing material toughness without sacrificing strength or stiffness. Nylon yarns and Kevlar (PPTA) yarns have been fabricated and tested (c) for use in the garment industry and for application in body armor. Parker is performing this research with returning veterans, an important component of the MRSEC outreach program.

Kevin K. Parker (Bioeng)
Harvard MRSEC (DMR-1420570)