March 12, 2012

New Polymer Production Method Inspired By Nature

Researchers at the University of Massachusetts Amherst have reportedly developed a new method for printing two-dimensional polymer sheets that can be folded into three-dimensional creations by simply adding water.

According to university and National Science Foundation (NSF) press releases, Christian Santangelo, Ryan Hayward and their colleagues were inspired by the way a flower petal naturally expands to develop a new techique that harnesses a technique called photolithography, in which a photomask and ultraviolet (UV) light is used to essentially print a pattern onto soft-gel polymer sheets.

When exposed to water when there are no UV rays present, the polymer "will swell and expand uniformly," the NSF said. However, when those same molecules are exposed to ultraviolet light, they became "crosslinked" or more tightly connected at certain points, which prevented them from expanding with the addition of water.

Using this knowledge, Santangelo, Hayward, and their associates are able to control how much each area of the polymer sheet expanded, then exposing them to UV light for a second time "to create specific 3-D shapes."

The University of Massachusetts Amherst researchers, who have published their research in the latest edition of the journal Science, believe that the technique could one day help biomedical researchers to control the form of laboratory-grown cells so that they form a specific organ, a blood vessel, or another part of the anatomy. They also believe the polymers could have applications in the fields of robotics and micro-optics.

"We wanted to develop a strategy that would allow us to pattern growth with some of the same flexibility that nature does," Hayward said in a statement on March 8.

"We´re discovering new ways to plan or pattern growth in a soft polymer gel that´s spread on a substrate to get any shape you want," added Santangelo. "By directly transferring the image onto the soft gel with half-tones of light, we direct its growth“¦ We aren´t sure yet how many shapes we can make this way, but for now it´s exciting to explore and we´re focused on understanding the process better."

Their work was supported by National Science Foundation (NSF) Faculty Early Career Development and Materials Research Science and Engineering Centers awards, the organization said, describing the work as a collaboration between both theoretical and experimental types of physics and polymer engineering.


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