Inspired by a cotton candy machine, engineers put a new spin on creating tiny nanofibers

May 25, 2010
Left: A diagram of the rotary jet spinner; upper right: The resulting "spun" nanofibers; bottom right: The nanofibers viewed at 10um. Credit: Kit Parker, Disease Biophysics Group at the Harvard School of Engineering and Applied Sciences

Hailed as a "cross between a high-speed centrifuge and a cotton candy machine," bioengineers at Harvard have developed a new, practical technology for fabricating tiny nanofibers.

The reference by lead author Mohammad Reza Badrossamay to the fairground treat of spun sugar is deliberate, as the device literally—and just as easily—spins, stretches, and pushes out 100 nanometer-diameter polymer-based threads using a rotating drum and nozzle.

The invention, reported in the May 24 online edition of , could be a boon for industry, with potential applications ranging from artificial organs and to clothing and air filters. The researchers have filed a patent on their discovery.

"This is a vastly superior method to making as compared to typical methods, with production output many times greater," says co-author Kit Parker, Thomas D. Cabot Associate Professor of Applied Science and Associate Professor of in the Harvard School of Engineering and Applied Sciences (SEAS); a core faculty member of the Wyss Institue for Biologically Inspired Engineering at Harvard; and member of the Harvard Stem Cell Institute. "Our technique will be highly desirable to industry, as the simple machines could easily bring nanofiber production into any laboratory. In effect, with this technique we can mainstream nanotextiles."

By contrast, the most common method of creating nanofibers is through electrospinning, or sending a high voltage electric change into a droplet of polymer liquid to draw out long wisps of nanoscale threads. While effective, electrospinning offers limited control and low output of the desired fibers.

The Harvard researchers turned to a simpler solution, using rotary jet spinning. Quickly feeding and then rotating the inside a reservoir atop a controllable motor offers more control and greater yield.

When spun, the material stretches much like molten sugar does as it begins to dry into thin, silky ribbons. Just as in cotton candy production, the nanofibers are extruded through a nozzle by a combination of hydrostatic and centrifugal pressure.

The resulting pile of extruded fibers form into a bagel like shape about 10 cm in diameter.

"The new system offers fabrication of naturally occurring and synthetic polymers as well as a lot of control over fiber alignment and web porosity, hierarchical and spatial organization of fibrous scaffold and three-dimensional assemblies," says Badrossamay, a postdoctoral fellow in the Wyss Institute and member of Parker's lab at SEAS.

The researchers tested the new device using a variety of synthetic and natural polymers such as polylactic acid in chloroform, a biodegradable polymer created from corn starch or sugarcane that has been used as eco-friendly alternative to plastic in items like disposable cups.

Moreover, the rapid spinning method provides a high degree of flexibility as the diameter of the fibers can be readily manipulated and the structures can be integrated into an aligned three-dimensional structure or any shape simply by varying how the fibers are collected.

The shape of the fibers can also be altered, ranging from beaded to textured to smooth.

Parker's Disease Biophysics Group (DBG), which has extensive expertise in cardiac tissue engineering, also used the technology to form tissue engineering scaffolds, or artificial structures upon which tissue can form and grow.

Heart tissue from rats was integrated and aligned with the nanofibers, and, as seen in past studies, formed beating muscle.

"I was visiting the Society of Laproscopic Surgeons a couple of years ago to look at the equipment demos and it dawned on me that we needed to develop techniques to miniaturize scaffold production so we could do it in vivo. Our finding is the first step," explains Parker. "The initial testing suggests that our technique is incredibly versatile for both research and everyday applications. As rotary jet spinning does not require high voltage, it really brings nanofiber fabrication to everyone."

The researchers expect to further refine the process for tissue engineering applications and to look for opportunities to exploit the advance in other textile applications.

Explore further: Study shows graphene able to withstand a speeding bullet

Related Stories

Nanomedicine opens the way for nerve cell regeneration

Jun 06, 2007

The ability to regenerate nerve cells in the body could reduce the effects of trauma and disease in a dramatic way. In two presentations at the NSTI Nanotech 2007 Conference, researchers describe the use of nanotechnology ...

Spinning a new yarn: silicone fibers with living organisms

Nov 20, 2006

In a feat once as unlikely as the miller's daughter of fairytale fame spinning straw into gold, scientists in the United Kingdom have spun fine threads of biocompatible silicone that contain living human brain cells. The ...

3D printing for new tissues and organs

Jun 18, 2009

A more effective way to build plastic scaffolds on which new tissues and even whole organs might be grown in the laboratory is being developed by an international collaboration between teams in Portugal and the UK.

Spun-sugar fibers spawn sweet technique for nerve repair

Feb 26, 2009

Researchers at Purdue University have developed a technique using spun-sugar filaments to create a scaffold of tiny synthetic tubes that might serve as conduits to regenerate nerves severed in accidents or ...

Recommended for you

Study shows graphene able to withstand a speeding bullet

16 hours ago

(Phys.org)—A team of researchers working at Rice University in the U.S. has demonstrated that graphene is better able to withstand the impact of a bullet than either steel or Kevlar. In their paper published ...

Nanomaterials to preserve ancient works of art

Nov 27, 2014

Little would we know about history if it weren't for books and works of art. But as time goes by, conserving this evidence of the past is becoming more and more of a struggle. Could this all change thanks ...

Learning anti-microbial physics from cicada

Nov 27, 2014

(Phys.org) —Inspired by the wing structure of a small fly, an NPL-led research team developed nano-patterned surfaces that resist bacterial adhesion while supporting the growth of human cells.

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

KronosDeret
not rated yet May 26, 2010
Hmm nanoclothing... i would definetly like to wear that, dust water and dirt rejecting material, that would breathe and keet me warm. Antiseptic properties, no sweating, no smell, sing me up :)

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.