Featured Research

from universities, journals, and other organizations

Material turns hard or soft at the touch of a button

Date:
June 6, 2011
Source:
Helmholtz Association of German Research Centres
Summary:
A world premiere: A material which changes its strength, virtually at the touch of a button. This transformation can be achieved in a matter of seconds through changes in the electron structure of a material; thus hard and brittle matter, for example, can become soft and malleable. What makes this development revolutionary, is that the transformation can be controlled by electric signals.

The nanomaterial under a scanning electron microscope.
Credit: Image courtesy of Helmholtz Association of German Research Centres

A world premiere: a material which changes its strength, virtually at the touch of a button. This transformation can be achieved in a matter of seconds through changes in the electron structure of a material; thus hard and brittle matter, for example, can become soft and malleable. What makes this development revolutionary, is that the transformation can be controlled by electric signals.

This world-first has its origins in Hamburg. Jörg Weißmüller, a materials scientist at both the Technical University of Hamburg and the Helmholtz Center Geesthacht, has carried out research on this groundbreaking development, working in cooperation with colleagues from the Institute for Metal Research in Shenyang, China.

The 51-year-old researcher from the Saarland referred to his fundamental research, which opens the door to a multitude of diverse applications, as "a breakthrough in the material sciences." The new metallic high-performance material is described by Prof. Dr. Jörg Weißmüller and the Chinese research scientist Hai-Jun Jin in the latest issue of the scientific journal Science. Their research findings could, for example, make future intelligent materials with the ability of self healing, smoothing out flaws autonomously.

The firmness of a boiled egg can be adjusted at will through the cooking time. Some decisions are, however, irrevocable -- a hard-boiled egg can never be reconverted into a soft-boiled one. There would be less annoyance at the breakfast table if we could simply switch back and forth between the different degrees of firmness of the egg.

Similar issues arise in the making of structural materials such as metals and alloys. The materials properties are set once and for all during production. This forces engineers to make compromises in the selection of the mechanical properties of a material. Greater strength is inevitably accompanied by increased brittleness and a reduction of the damage tolerance.

Professor Weißmüller, head of the Institute of Materials Physics and Technology at the Technical University of Hamburg and also of the department for Hybrid Material Systems at the Helmholtz Center Geesthacht, stated: "This is a point where significant progress is being made. For the first time we have succeeded in producing a material which, while in service, can switch back and forth between a state of strong and brittle behavior and one of soft and malleable. We are still at the fundamental research stage but our discovery may bring significant progress in the development of so-called smart materials."

A Marriage of Metal and Water

In order to produce this innovative material, material scientists employ a comparatively simple process: corrosion. The metals, typically precious metals such as gold or platinum, are placed in an acidic solution. As a consequence of the onset of the corrosion process, minute ducts and holes are formed in the metal. The emerging nanostructured material is pervaded by a network of pore channels.

The pores are impregnated with a conductive liquid, for example a simple saline solution or a diluted acid, and a true hybrid material of metal and liquid is thus created. It is the unusual "marriage," as Weißmüller calls this union of metal and water which, when triggered by an electric signal, enables the properties of the material to change at the touch of a button.

As ions are dissolved in the liquid, the surfaces of the metal can be electrically charged. In other words, the mechanical properties of the metallic partner are changed by the application of an electric potential in the liquid partner. The effect can be traced back to a strengthening or weakening of the atomic bonding in the surface of the metal when extra electrons are added to or withdrawn from the surface atoms. The strength of the material can be as much as doubled when required. Alternatively, the material can be switched to a state which is weaker, but more damage tolerant, energy-absorbing and malleable.

Specific applications are still a matter for the future. However, researchers are already thinking ahead. In principle, the material can create electric signals spontaneously and selectively, so as to strengthen the matter in regions of local stress concentration. Damage, for instance in the form of cracks, could thereby be prevented or even healed. This has brought scientists a great step closer to their objective of 'intelligent' high performance materials.


Story Source:

The above story is based on materials provided by Helmholtz Association of German Research Centres. Note: Materials may be edited for content and length.


Journal Reference:

  1. H.-J. Jin, J. Weissmuller. A Material with Electrically Tunable Strength and Flow Stress. Science, 2011; 332 (6034): 1179 DOI: 10.1126/science.1202190

Cite This Page:

Helmholtz Association of German Research Centres. "Material turns hard or soft at the touch of a button." ScienceDaily. ScienceDaily, 6 June 2011. <www.sciencedaily.com/releases/2011/06/110606113106.htm>.
Helmholtz Association of German Research Centres. (2011, June 6). Material turns hard or soft at the touch of a button. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2011/06/110606113106.htm
Helmholtz Association of German Research Centres. "Material turns hard or soft at the touch of a button." ScienceDaily. www.sciencedaily.com/releases/2011/06/110606113106.htm (accessed October 1, 2014).

Share This



More Matter & Energy News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

US Police Put Body Cameras to the Test

US Police Put Body Cameras to the Test

AFP (Oct. 1, 2014) — Police body cameras are gradually being rolled out across the US, with interest surging after the fatal police shooting in August of an unarmed black teenager. Duration: 02:18 Video provided by AFP
Powered by NewsLook.com
Raw: Japan Celebrates 'bullet Train' Anniversary

Raw: Japan Celebrates 'bullet Train' Anniversary

AP (Oct. 1, 2014) — A ceremony marking 50 years since Japan launched its Shinkansen bullet train was held on Wednesday in Tokyo. The latest model can travel from Tokyo to Osaka, a distance of 319 miles, in two hours and 25 minutes. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Robotic Hair Restoration

Robotic Hair Restoration

Ivanhoe (Oct. 1, 2014) — A new robotic procedure is changing the way we transplant hair. The ARTAS robot leaves no linear scarring and provides more natural results. Video provided by Ivanhoe
Powered by NewsLook.com
Argentina's Tax Evaders Detected, Hunted Down by Drones

Argentina's Tax Evaders Detected, Hunted Down by Drones

AFP (Sep. 30, 2014) — Argentina doesn't only have Lionel Messi the footballer, it has now also acquired "Mesi" the drone system which monitors undeclared mansions, swimming pools and soy fields to curb tax evasion in the country. Duration: 01:18 Video provided by AFP
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