Featured Research

from universities, journals, and other organizations

Unique light-activated membrane acts like a traffic signal for gas

Date:
August 2, 2010
Source:
University of Rochester
Summary:
A newly developed membrane blocks gas from flowing through it when one color of light is shined on its surface, and permits gas to flow through when another color of light is used. It is the first time that scientists have developed a membrane that can be controlled in this way by light.

A new membrane developed at the University of Rochester's Laboratory for Laser Energetics blocks gas from flowing through it when one color of light is shined on its surface, and permits gas to flow through when another color of light is used. It is the first time that scientists have developed a membrane that can be controlled in this way by light.

Related Articles


Eric Glowacki, a graduate student at the University's Laboratory for Laser Energetics, and Kenneth Marshall, his advisor, invented the membrane. Marshall will present their findings at the annual conference of the International Society for Optics and Photonics (SPIE) in San Diego on Aug. 1.

The membrane is a piece of hard plastic riddled with tiny holes that are filled with liquid crystals and a dye. When purple light illuminates the surface of the membrane, the dye molecules straighten out and the liquid crystals fall into line, which allows gas to easily flow through the holes. But when ultraviolet light illuminates the surface, the dye molecules bend into a banana shape and the liquid crystals scatter into random orientations, clogging the tunnel and blocking gas from penetrating.

Controlling a membrane's permeability with light is preferable to controlling it with heat or electricity -- two readily used alternative methods -- for several reasons, Glowacki said. For starters, light can operate remotely. Instead of attaching electrical lines to the membrane, a lamp or a laser can be directed at the membrane from a distance. This could allow engineers to make much smaller, simpler setups.

Another advantage is that the color of the light illuminating the membrane can be changed precisely and almost instantaneously. Other methods, like heating and cooling, take a relatively long time and repeated heating and cooling can damage the membrane.

Also, light does not have the potential to ignite a gas, which could be a crucial benefit when working with hydrocarbons or other flammable gases. Lastly, the amount of light energy needed to switch the membrane on and off is miniscule.

Creating the membrane is a multi-step process. First, a circular hard plastic chip is bombarded with a beam of neutrons to make the tiny, evenly spaced holes that are about one-hundredth of a millimeter in diameter. The chip is then dipped in a solution of liquid crystals and dye, and the mixture fills the holes through capillary action. The final product is spun in a centrifuge to remove the excess liquid crystals from the surface.

The membrane could be useful in controlled drug delivery and industrial processing tasks that require the ability to turn the flow of gas on and off as well as in research applications.


Story Source:

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


Cite This Page:

University of Rochester. "Unique light-activated membrane acts like a traffic signal for gas." ScienceDaily. ScienceDaily, 2 August 2010. <www.sciencedaily.com/releases/2010/08/100801101912.htm>.
University of Rochester. (2010, August 2). Unique light-activated membrane acts like a traffic signal for gas. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2010/08/100801101912.htm
University of Rochester. "Unique light-activated membrane acts like a traffic signal for gas." ScienceDaily. www.sciencedaily.com/releases/2010/08/100801101912.htm (accessed October 25, 2014).

Share This



More Matter & Energy News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
Real-Life Transformer Robot Walks, Then Folds Into a Car

Real-Life Transformer Robot Walks, Then Folds Into a Car

Buzz60 (Oct. 24, 2014) Brave Robotics and Asratec teamed with original Transformers toy company Tomy to create a functional 5-foot-tall humanoid robot that can march and fold itself into a 3-foot-long sports car. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Police Testing New Gunfire Tracking Technology

Police Testing New Gunfire Tracking Technology

AP (Oct. 24, 2014) A California-based startup has designed new law enforcement technology that aims to automatically alert dispatch when an officer's gun is unholstered and fired. Two law enforcement agencies are currently testing the technology. (Oct. 24) Video provided by AP
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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