Featured Research

from universities, journals, and other organizations

Intricate, curving 3-D nanostructures created using capillary action forces

Date:
October 20, 2010
Source:
University of Michigan
Summary:
Twisting spires, concentric rings, and gracefully bending petals are a few of the new three-dimensional shapes that engineers can make from carbon nanotubes using a new manufacturing process.

Twisting spires are one of the 3-D shapes researchers at the University of Michigan were able to develop using a new manufacturing process.
Credit: A. John Hart

Twisting spires, concentric rings, and gracefully bending petals are a few of the new three-dimensional shapes that University of Michigan engineers can make from carbon nanotubes using a new manufacturing process.

Related Articles


The process is called "capillary forming," and it takes advantage of capillary action, the phenomenon at work when liquids seem to defy gravity and travel up a drinking straw of their own accord.

The new miniature shapes, which are difficult if not impossible to build using any material, have the potential to harness the exceptional mechanical, thermal, electrical, and chemical properties of carbon nanotubes in a scalable fashion, said A. John Hart, an assistant professor in the Department of Mechanical Engineering and in the School of Art & Design.

They could lead to probes that can interface with individual cells and tissues, novel microfluidic devices, and new materials with a custom patchwork of surface textures and properties.

A paper on the research is published in the October edition of Advanced Materials, and is featured on the cover.

"It's easy to make carbon nanotubes straight and vertical like buildings," Hart said. "It hasn't been possible to make them into more complex shapes. Assembling nanostructures into three-dimensional shapes is one of the major goals of nanotechnology. The method of capillary forming could be applied to many types of nanotubes and nanowires, and its scalability is very attractive for manufacturing."

Hart's method starts by stamping patterns on a silicon wafer. His ink in this case is the iron catalyst that facilitates the vertical growth of the carbon nanotubes in the patterned shapes. Rather than stamp a traditional, uniform grid of circles, Hart stamp hollow circles, half circles and circles with smaller ones cut from their centers. The shapes are arranged in different orientations and groupings. One such grouping is a pentagon of half circles with their flat sides facing outward.

He uses the traditional "chemical vapor deposition" process to grow the nanotubes in the prescribed patterns. Then he suspends the silicon wafer with its nanotube forest over a beaker of a boiling solvent, such as acetone. He lets the acetone condense on the nanotubes, and then lets the acetone evaporate.

As the liquid condenses, capillary action forces kick in and transform the vertical nanotubes into the intricate three-dimensional structures. For example, tall half-cylinders of nanotubes bend backwards to form a shape resembling a three-dimensional flower.

"We program the formation of 3-D shapes with these 2-D patterns," Hart said. "We've discovered that the starting shape influences how the capillary forces change the structures' geometry. Some bend, others twist, and we can combine them any way we want."

The capillary forming process allows the researchers to create large batches of 3-D microstructures -- all much smaller than a cubic millimeter -- over essentially limitless areas, Hart said. In addition, the researchers show that their 3-D structures are up to 10 times stiffer than typical polymers used in microfabrication. Thus, they can be used as molds for manufacturing of the same 3-D shapes in other materials.

"We'd like to think this opens up the idea of creating custom nanostructured surfaces and materials with locally varying geometries and properties, " Hart said. "Now, we think of materials as having the same properties everywhere, but with this new technique we can dream of designing the structure and properties of a material together."

This research is funded by the University of Michigan College of Engineering and the U-M Department of Mechanical Engineering, the Belgium Fund for Scientific Research, and the National Science Foundation.

The university is pursuing patent protection for the intellectual property, and is seeking commercialization partners to help bring the technology to market.


Story Source:

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


Journal Reference:

  1. Michael De Volder, Sameh H. Tawfick, Sei Jin Park, Davor Copic, Zhouzhou Zhao, Wei Lu and A. John Hart. Capillary Forming: Diverse 3D Microarchitectures Made by Capillary Forming of Carbon Nanotubes. Advanced Materials, 2010; DOI: 10.1002/adma.201090127

Cite This Page:

University of Michigan. "Intricate, curving 3-D nanostructures created using capillary action forces." ScienceDaily. ScienceDaily, 20 October 2010. <www.sciencedaily.com/releases/2010/10/101019132052.htm>.
University of Michigan. (2010, October 20). Intricate, curving 3-D nanostructures created using capillary action forces. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2010/10/101019132052.htm
University of Michigan. "Intricate, curving 3-D nanostructures created using capillary action forces." ScienceDaily. www.sciencedaily.com/releases/2010/10/101019132052.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NASA's First 3-D Printer In Space Creates Its First Object

NASA's First 3-D Printer In Space Creates Its First Object

Newsy (Nov. 26, 2014) The International Space Station is now using a proof-of-concept 3D printer to test additive printing in a weightless, isolated environment. Video provided by Newsy
Powered by NewsLook.com
Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Reuters - Innovations Video Online (Nov. 26, 2014) Innovative recycling project in La Paz separates city waste and converts plastic garbage into school furniture made from 'plastiwood'. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Blu-Ray Discs Getting Second Run As Solar Panels

Blu-Ray Discs Getting Second Run As Solar Panels

Newsy (Nov. 26, 2014) Researchers at Northwestern University are repurposing Blu-ray movies for better solar panel technology thanks to the discs' internal structures. Video provided by Newsy
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
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