PULL SPINNING:

Point-and-Shoot Nanofibers

2014-2017

Pull Spinning in Action

Video: Leila Deravi

Journal Cover Image

Pull Spinning is a novel nanofiber manufacturing process developed in the Disease Biophysics Group at Harvard SEAS. The original inspiration for the method was the motion of a cat's tongue as it draws milk from a saucer, and the technique has evolved to a portable, point-of-use fiber fabrication system that supports a wide range of polymer and protein materials.

Unlike many other nanofiber fabrication systems, pull spinning does not rely on a high electric field to extrude nanofibers. Instead, a combination of viscous and centrifugal forces contribute to nanofiber formation:

  • First, a polymer, protein, or biohybrid solution is infused through a needle reservoir.

  • Then, a rotating bristle attached to a high-speed motor strikes the droplet that forms at the top of the needle. The bristle pulls and elongates the droplet into a polymer jet within 35 milliseconds.

  • As the bristle pulls the jet through one revolution, the solvent evaporates from the polymer solution, forming a single nanofiber.

  • As the bristle subsequently contacts the polymer reservoir, the nanofiber is projected linearly toward a collector. This process continues until a network of nanofibers have formed.

Pull spun nanofabrics can be used for a variety of applications, including muscle tissue engineering and point-of-wear apparel. The combination of minimal processing parameters, portability, high control of fiber deposition, flexible substrate materials distinguish pull spinning as a robust and easy- to-use platform for nanofiber manufacturing. 

This project was published on the cover of Macromolecular Materials and Engineering.

Image: Karaghen Hudson

Image: Christophe Chantre

Image: Christophe Chantre

© 2016-2018 by NINA SINATRA

Pull Spinning + Tissue Engineering

Immunofluorescence staining of murine skeletal muscle, cultured on pull spun fiber muscular thin films. Nanofiber scaffolds support myoblast fusion and maturation into functional muscle tissue. Moreover, it was possible to measure dynamic stress values with quantifiable twitch and tetanus curves - key clinical metrics for skeletal muscle. Adapted from Deravi and Sinatra et al, 2017

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