Featured Research

from universities, journals, and other organizations

New coating turns ordinary glass into super glass

Date:
August 4, 2013
Source:
Wyss Institute for Biologically Inspired Engineering at Harvard
Summary:
A new transparent, bioinspired coating makes ordinary glass tough, self-cleaning and incredibly slippery.

The tiny, tightly packed cells of the honeycomb-like structure, shown here in this electron micrograph, make the SLIPS coating highly durable.
Credit: Nicolas Vogel, Wyss Institute.

A new transparent, bioinspired coating makes ordinary glass tough, self-cleaning, and incredibly slippery, a team from the Wyss Institute for Biologically Inspired Engineering at Harvard University and Harvard School of Engineering and Applied Sciences (SEAS) reported online in the July 31 edition of Nature Communications.

The new coating could be used to create durable, scratch-resistant lenses for eyeglasses, self-cleaning windows, improved solar panels, and new medical diagnostic devices, said principal investigator Joanna Aizenberg, Ph.D., who is a Core Faculty Member at the Wyss Institute, Amy Smith Berylson Professor of Materials Science at SEAS, and a Professor of Chemistry and Chemical Biology.

The new coating builds on an award-winning technology that Aizenberg and her team pioneered called Slippery Liquid-Infused Porous Surfaces (SLIPS) -- the slipperiest synthetic surface known. The new coating is equally slippery, but much more durable and fully transparent. Together these advances solve longstanding challenges in creating commercially useful materials that repel almost everything.

SLIPS was inspired by the slick strategy of the carnivorous pitcher plant, which lures insects onto the ultraslippery surface of its leaves, where they slide to their doom. Unlike earlier water-repelling materials, SLIPS repels oil and sticky liquids like honey, and it resists ice formation and bacterial biofilms as well.

While SLIPS was an important advance, it was also "a proof of principle" -- the first step toward a commercially valuable technology, said lead author Nicolas Vogel, Ph.D., a postdoctoral fellow in applied physics at Harvard SEAS.

"SLIPS repels both oily and aqueous liquids but it's expensive to make and not transparent," Vogel said.

The original SLIPS materials also need to be fastened somehow to existing surfaces, which is often not easy.

"It would be easier to take the existing surface and treat it in a certain way to make it slippery," Vogel explained.

Vogel, Aizenberg, and their colleagues sought to develop a coating that accomplishes this and works as SLIPS does. SLIPS's thin layer of liquid lubricant allows liquids to flow easily over the surface, much as a thin layer of water in an ice rink helps an ice skater glide.

To create a SLIPS-like coating, the researchers corral a collection of tiny spherical particles of polystyrene, the main ingredient of Styrofoam, on a flat glass surface, like a collection of Ping-Pong balls. They pour liquid glass on them until the balls are more than half buried in glass. After the glass solidifies, they burn away the beads, leaving a network of craters that resembles a honeycomb. They then coat that honeycomb with the same liquid lubricant used in SLIPS to create a tough but slippery coating.

"The honeycomb structure is what confers the mechanical stability to the new coating," said Aizenberg.

By adjusting the width of the honeycomb cells to make them much smaller in diameter than the wavelength of visible light, the researchers kept the coating from reflecting light. This made a glass slide with the coating completely transparent.

These coated glass slides repelled a variety of liquids, just as SLIPS does, including water, octane, wine, olive oil, and ketchup. And, like SLIPS, the coating reduced the adhesion of ice to a glass slide by 99 percent. Keeping materials frost-free is important because adhered ice can take down power lines, decrease the energy efficiency of cooling systems, delay airplanes, and lead buildings to collapse.

Importantly, the honeycomb structure of the SLIPS coating on the glass slides confers unmatched mechanical robustness. It withstood damage and remained slippery after various treatments that can scratch and compromise ordinary glass surfaces and other popular liquid-repellent materials, including touching, peeling off a piece of tape, and wiping with a tissue.

"We set ourselves a challenging goal: to design a versatile coating that's as good as SLIPS but much easier to apply, transparent, and much tougher -- and that is what we managed," Aizenberg said.

The team is now honing its method to better coat curved pieces of glass as well as clear plastics such as Plexiglas, and to adapt the method for the rigors of manufacturing.

"Joanna's new SLIPS coating reveals the power of following Nature's lead in developing new technologies," said Don Ingber, M.D., Ph.D., the Wyss Institute's Founding Director. "We are excited about the range of applications that could use this innovative coating." Ingber is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Boston Children's Hospital, and Professor of Bioengineering at Harvard SEAS.

This work was funded by the Advanced Research Projects Agency-Energy (ARPA-E), the Air Force Office of Scientific Research, and the Wyss Institute. Nicolas Vogel received funding from the Leopoldina Fellowship program. In addition to Vogel and Aizenberg, the research team included: Rebecca A. Belisle, a former Wyss research assistant who is now a graduate student in Materials Science and Engineering at Stanford University; Benjamin Hatton, Ph.D., formerly a Technology Development fellow at the the Wyss Institute and a research appointee at SEAS who is now an assistant professor of materials science and engineering at the University of Toronto; and Tak-Sing Wong, Ph.D., a former postdoctoral research fellow at the Wyss Institute who is now an Assistant Professor of Mechanical and Nuclear Engineering at Penn State University.


Story Source:

The above story is based on materials provided by Wyss Institute for Biologically Inspired Engineering at Harvard. Note: Materials may be edited for content and length.


Journal Reference:

  1. Nicolas Vogel, Rebecca A. Belisle, Benjamin Hatton, Tak-Sing Wong, Joanna Aizenberg. Transparency and damage tolerance of patternable omniphobic lubricated surfaces based on inverse colloidal monolayers. Nature Communications, 2013; 4 DOI: 10.1038/ncomms3176

Cite This Page:

Wyss Institute for Biologically Inspired Engineering at Harvard. "New coating turns ordinary glass into super glass." ScienceDaily. ScienceDaily, 4 August 2013. <www.sciencedaily.com/releases/2013/08/130804081123.htm>.
Wyss Institute for Biologically Inspired Engineering at Harvard. (2013, August 4). New coating turns ordinary glass into super glass. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2013/08/130804081123.htm
Wyss Institute for Biologically Inspired Engineering at Harvard. "New coating turns ordinary glass into super glass." ScienceDaily. www.sciencedaily.com/releases/2013/08/130804081123.htm (accessed July 25, 2014).

Share This




More Matter & Energy News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com
Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) 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:
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