Featured Research

from universities, journals, and other organizations

Engineering researchers simplify process to make world's tiniest wires

Date:
July 22, 2010
Source:
University of Florida
Summary:
Surface tension isn't a very powerful force, but it matters for small things -- water bugs, paint, and, it turns out, nanowires.

Top: Clumps of extremely tiny nanowires in this image are captured with the aid of an electron microscope. The clumping pattern, which occurs as a result of surface tension during the manufacturing process, limits the usefulness of the wires, which are viewed as a likely core element of more powerful microelectronics, solar cells, batteries and medical tools. Bottom: In this image captured with the aid of an electron microscope, nanowires stand straight up as a result of a new process developed by University of Florida chemical engineering researchers. The engineers apply an electrical charge to the nanostructure during the manufacturing process, charging each wire and making it repel its neighbor, counteracting the opposite force induced by the surface tension. The researchers say the process is inexpensive and simple, a step toward making the nanowires a more common constituent of electronics, medical devices and solar cells.
Credit: Image courtesy of University of Florida

Surface tension isn't a very powerful force, but it matters for small things -- water bugs, paint, and, it turns out, nanowires.

Related Articles


Nanowires are so tiny that a human hair would dwarf them -- some have diameters 150 billionths of a meter. Because of their small size, surface tension that occurs during the manufacturing process pulls them together, limiting their usefulness. This is a problem because the wires are seen as a potential core element of new and more powerful microelectronics, solar cells, batteries and medical tools.

But in a paper in the journal ACS Applied Materials & Interfaces now online, a University of Florida engineering researcher says he has found an inexpensive solution.

Kirk Ziegler, an assistant professor of chemical engineering, said nanowires are most often made today with a process that involves the immersion of the wires.

When complete, each wire is supposed to poke up right next to the other from a flat surface, like bristles on a Lilliputian toothbrush. But Ziegler said the wires are so tiny and so flexible that surface tension clumps them up when dried.

Manufacturers use extremely high pressure to reduce the surface tension, but Ziegler said that process is difficult, expensive and not conducive to large-scale production.

Ziegler and Justin Hill, who will graduate from UF with a doctorate in chemical engineering this summer, realized that they needed to introduce a force that counteracted that of the surface tension. They came up with a process simple enough to be achievable with a nine-volt battery. The researchers apply an electrical charge to the nanostructures during the manufacturing process, charging each tiny wire and making it repel its neighbor.

"As the two nanowires pull toward each other because of the surface tension, the like charges at the tips act to push them apart," Ziegler said. "The aim is to get a net zero force on the structure, so the nanowires stand straight."

Tests of microscope-slide-sized surfaces, each containing trillions of nanowires, showed that the procedure effectively prevents clumping, Ziegler said.

Nanowires have not found wide commercial applications to date, but Ziegler said that as engineers learn how to make and manipulate them, they could underpin far more efficient solar cells and batteries because they provide more surface area and better electrical properties.

"Being able to pack in a higher density of nanowires gives you a much higher surface area, so you start to generate higher energy density," he said.

Ziegler said that biomedical engineers are also interested in using the wires to help deliver drugs to individual cells, or to hinder or encourage individual cell growth. The University of Florida has applied for a patent on the process, he added.


Story Source:

The above story is based on materials provided by University of Florida. The original article was written by Aaron Hoover. Note: Materials may be edited for content and length.


Journal Reference:

  1. Justin J. Hill, Kelly Haller, Brittany Gelfand and Kirk J. Ziegler. Eliminating Capillary Coalescence of Nanowire Arrays with Applied Electric Fields. ACS Applied Materials & Interfaces, 2010; [link]

Cite This Page:

University of Florida. "Engineering researchers simplify process to make world's tiniest wires." ScienceDaily. ScienceDaily, 22 July 2010. <www.sciencedaily.com/releases/2010/07/100721112242.htm>.
University of Florida. (2010, July 22). Engineering researchers simplify process to make world's tiniest wires. ScienceDaily. Retrieved October 30, 2014 from www.sciencedaily.com/releases/2010/07/100721112242.htm
University of Florida. "Engineering researchers simplify process to make world's tiniest wires." ScienceDaily. www.sciencedaily.com/releases/2010/07/100721112242.htm (accessed October 30, 2014).

Share This



More Matter & Energy News

Thursday, October 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Mind-Controlled Prosthetic Arm Restores Amputee Dexterity

Mind-Controlled Prosthetic Arm Restores Amputee Dexterity

Reuters - Innovations Video Online (Oct. 29, 2014) A Swedish amputee who became the first person to ever receive a brain controlled prosthetic arm is able to manipulate and handle delicate objects with an unprecedented level of dexterity. The device is connected directly to his bone, nerves and muscles, giving him the ability to control it with his thoughts. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Robots Get Funky on the Dance Floor

Robots Get Funky on the Dance Floor

AP (Oct. 29, 2014) Dancing, spinning and fighting robots are showing off their agility at "Robocomp" in Krakow. (Oct. 29) Video provided by AP
Powered by NewsLook.com
Saharan Solar Project to Power Europe

Saharan Solar Project to Power Europe

Reuters - Business Video Online (Oct. 29, 2014) A solar energy project in the Tunisian Sahara aims to generate enough clean energy by 2018 to power two million European homes. Matt Stock reports. Video provided by Reuters
Powered by NewsLook.com
Lowe's Testing Robot Sales Assistants in California Store

Lowe's Testing Robot Sales Assistants in California Store

Buzz60 (Oct. 29, 2014) Lowe’s is testing out what it’s describing as a robotic shopping assistant in one of its Orchard Supply Hardware Stores in California. Jen Markham explains. Video provided by Buzz60
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