Featured Research

from universities, journals, and other organizations

Good hair day: New technique grows tiny 'hairy' materials at the microscale

Date:
February 4, 2014
Source:
DOE/Argonne National Laboratory
Summary:
Scientists attacked a tangled problem by developing a new technique to grow tiny "hairy" materials that assemble themselves at the microscale. It looks like the way Chia Pets grow in commercials. The key ingredient is epoxy, which is added to a mixture of hardener and solvent inside an electric cell. Then the scientists run an alternating current through the cell and watch long, twisting fibers spring up.

Argonne materials scientists announced a new technique to grow these little forests at the microscale (the scale shows 100 micrometers, which is about the diameter of a single human hair).
Credit: Alexey Snezhko and Igor Aronson

Scientists at the U.S. Department of Energy's Argonne National Laboratory attacked a tangled problem by developing a new technique to grow tiny "hairy" materials that assemble themselves at the microscale, published this week in Nature Communications. The key ingredient is epoxy, which is added to a mixture of hardener and solvent inside an electric cell. Then the scientists run an alternating current through the cell and watch long, twisting fibers spring up.

It looks like the way Chia Pets grow in commercials. Argonne materials scientists announced a new technique to grow these little forests at the microscale (the scale shows 100 micrometers, which is about the diameter of a single human hair).

"The process is very simple, the materials are cheap and available and they can grow on almost every surface we've tried," said Argonne physicist Igor Aronson, who co-authored the study.

By tweaking the process, the team can grow many different shapes: short forests of dense straight hairs, long branching strands or "mushrooms" with tiny pearls at the tips. Interestingly, though the structures can be permanent, the process is also instantly reversible.

"This is a completely new kind of structure," said Argonne physicist Alexey Snezhko, also a co-author. "With this method, you can support more complex structures that have unique properties."

Scientists are very interested in materials with tiny fibers for technologies like batteries, photovoltaic cells or sensors. For one, "hairy" materials offer up a lot of surface area. Many chemical reactions depend on two surfaces making contact with one another, so a structure that exposes a lot of surface area will speed the process along. (For example, grinding coffee beans gives the coffee more flavor than soaking whole beans in water.) Micro-size hairs can also make a surface that repels water, called superhydrophobic, or dust.

The tiny-fiber structure is so useful that it's evolved several times in nature, Aronson pointed out. For example, blood vessels are lined with a layer of similar tiny protein "hairs," thought to help reduce wear and tear by blood cells and bacterial infections, among other properties.

Currently, the primary methods of creating interesting shapes at small scales is lithography, a type of "printing" where researchers lay a pattern on the material and the rest of it is melted or etched away. But it's hard to make very complex structures with this method; it's hard to control; and the results aren't always uniform.

"These polymers assemble themselves," Snezhko explained, "which is much easier and less labor-intensive than lithography."

In one experiment the researchers used a process called atomic layer deposition that deposits a molecule-thick layer of material over the entire hairy structure, like a fresh blanket of snow, to add a layer of semiconductor material. Semiconductors are essential ingredients in many technologies, such as solar cells and electronics. This provided proof of concept that the polymer could be incorporated into semiconductor-based renewable energy technologies. It also proved that it could survive high temperatures, up to 150°C, an essential property for many manufacturing processes.

Right now the structures are about a single micron thick -- you could stack 100 of them to reach the width of a sheet of paper. Aronson and Snezhko said their next goal is to get them even smaller, to the nanoscale.


Story Source:

The above story is based on materials provided by DOE/Argonne National Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Arnaud Demortiθre, Alexey Snezhko, Maksim V. Sapozhnikov, Nicholas Becker, Thomas Proslier, Igor S. Aranson. Self-assembled tunable networks of sticky colloidal particles. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4117

Cite This Page:

DOE/Argonne National Laboratory. "Good hair day: New technique grows tiny 'hairy' materials at the microscale." ScienceDaily. ScienceDaily, 4 February 2014. <www.sciencedaily.com/releases/2014/02/140204154642.htm>.
DOE/Argonne National Laboratory. (2014, February 4). Good hair day: New technique grows tiny 'hairy' materials at the microscale. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2014/02/140204154642.htm
DOE/Argonne National Laboratory. "Good hair day: New technique grows tiny 'hairy' materials at the microscale." ScienceDaily. www.sciencedaily.com/releases/2014/02/140204154642.htm (accessed September 1, 2014).

Share This




More Matter & Energy News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) — Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) — Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) — Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) — An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. 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