Featured Research

from universities, journals, and other organizations

Morphing material has mighty potential: Composite may find use in bioscaffolds, optics, drugs

Date:
December 9, 2013
Source:
Rice University
Summary:
The shape of a new composite material changes with the temperature in highly controllable ways. The material may be useful for biological, optical and pharmaceutical applications.

A composite material created by scientists at Rice University changes shape in a predetermined pattern when heated and changes back when cooled. The morphing material may be useful for bioengineering, optical, pharmaceutical and other applications.
Credit: Jeff Fitlow/Rice University

Heating a sheet of plastic may not bring it to life -- but it sure looks like it does in new experiments at Rice University.

The materials created by Rice polymer scientist Rafael Verduzco and his colleagues start as flat slabs, but they morph into shapes that can be controlled by patterns written into their layers.

The research is the subject of a new paper in the Royal Society of Chemistry journal Soft Matter.

Materials that can change their shape based on environmental conditions are useful for optics, three-dimensional biological scaffolds and the controlled encapsulation and release of drugs, among other applications, the researchers wrote.

"We already know the materials are biocompatible, stable and inert," Verduzco said, "so they have great potential for biological applications."

The material needs two layers to perform its magic, Verduzco said. One is a liquid crystal elastomer (LCE), a rubber-like material of cross-linked polymers that line up along a single axis, called the "nematic director." The other is a thin layer of simple polystyrene, placed either above or below the LCE.

Without the polystyrene layer bonded to it, an LCE would simply expand or contract along its nematic axis when heated. With changing temperature, the LCE tries to contract or expand, but the stiffer polystyrene layer prevents this and instead causes wrinkling, bending or folding of the entire material.

The lab discovered that the layers would react to heat in a predictable and repeatable way, allowing for configurations to be designed into the material depending on a number of parameters: the shape and aspect ratio of the LCE, the thickness and patterning of the polystyrene and even the temperature at which the polystyrene was applied.

The lab made spiraling, curling and X-shaped materials that alternately closed in or stood up on four legs. Placing polystyrene on top of one half of a strip of LCE and on the bottom of the other half produced an "S" shape. Verduzco suggested there's no limit to the complexity of the shapes that could be teased from the material with proper patterning.

The primary direction of folding or wrinkling of the material was set by the temperature at which the polystyrene layer was deposited. In experiments, the researchers found that when the polystyrene layer was applied at 5-6 degrees Celsius (about 42 degrees Fahrenheit), the material would wrinkle perpendicular to the LCE's nematic director. At 50 C (122 degrees F), the polystyrene wrinkled parallel to the director. The micrometer-scale wrinkles seemed smooth to the naked eye.

As expected, however, if the polystyrene layer was too thick, it would not allow the composite material to bend. And if the temperature got too hot, the polystyrene would pass its glass transition temperature and allow the composite to relax back into its flat shape. When the material cooled to room temperature and the polystyrene became glassy again, it would deform in the opposite direction, but it could return to its initial flat-at-room-temperature state if annealed with a solvent, dicloromethane, that relaxed the layers once more.

"For any application, you would want to be able to change shape and then go back," Verduzco said. "LCEs are reversible, unlike shape-memory polymers that change shape only once and cannot go back to their initial shape.

"This is important for biomedical applications, such as dynamic substrates for cell cultures or implantable materials that contract and expand in response to stimulus. This is what we are targeting with these applications."

Lead author Aditya Agrawal and co-author Stacy Pesek are graduate students and Tae Hyun Yun is an undergraduate at Rice. Co-author Walter Chapman is the William W. Akers Professor of Chemical and Biomolecular Engineering at Rice. Verduzco is an assistant professor of chemical and biomolecular engineering.

The John S. Dunn Foundation Collaborative Research Award Program administered by the Gulf Coast Consortia and the American Chemical Society Petroleum Research Fund supported the research.

Video: http://www.youtube.com/watch?v=ygcsNTFdH20


Story Source:

The above story is based on materials provided by Rice University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Aditya Agrawal, TaeHyun Yun, Stacy L. Pesek, Walter G. Chapman, Rafael Verduzco. Shape-responsive liquid crystal elastomer bilayers. Soft Matter, 2014; DOI: 10.1039/C3SM51654G

Cite This Page:

Rice University. "Morphing material has mighty potential: Composite may find use in bioscaffolds, optics, drugs." ScienceDaily. ScienceDaily, 9 December 2013. <www.sciencedaily.com/releases/2013/12/131209124103.htm>.
Rice University. (2013, December 9). Morphing material has mighty potential: Composite may find use in bioscaffolds, optics, drugs. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2013/12/131209124103.htm
Rice University. "Morphing material has mighty potential: Composite may find use in bioscaffolds, optics, drugs." ScienceDaily. www.sciencedaily.com/releases/2013/12/131209124103.htm (accessed September 16, 2014).

Share This



More Matter & Energy News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

Newsy (Sep. 16, 2014) MIT developed a robot modeled after a cheetah. It can run up to speeds of 10 mph, though researchers estimate it will eventually reach 30 mph. Video provided by Newsy
Powered by NewsLook.com
Manufacturer Prints 3-D Car In Record Time

Manufacturer Prints 3-D Car In Record Time

Newsy (Sep. 15, 2014) Automobile manufacturer Local Motors created a drivable electric car using a 3-D printer. Printing the body only took 44 hours. Video provided by Newsy
Powered by NewsLook.com
Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Reuters - US Online Video (Sep. 15, 2014) New York officials unveil subway tunnels that were refurbished after Superstorm Sandy. Nathan Frandino reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins