Made-To-Order Materials: Engineers Focus On the Nano to Create Strong, Lightweight Materials
The lightweight skeletons of organisms such as sea sponges display a strength that far exceeds that of humanmade products constructed from similar materials.
Scientists have long suspected that the difference has to do with the hierarchical architecture of the biological materials -- the way the silica-based skeletons are built up from different structural elements, some of which are measured on the scale of billionths of meters, or nanometers. Now engineers at the California Institute of Technology (Caltech) have mimicked such a structure by creating nanostructured, hollow ceramic scaffolds, and have found that the small building blocks, or unit cells, do indeed display remarkable strength and resistance to failure despite being more than 85 percent air.
Three-dimensional, hollow titanium nitride nanotruss with tessellated octahedral geometry. Each unit cell is on the order of 10 microns, each strut length within the unit cell is about three to five microns, the diameter of each strut is less than one micron, and the thickness of titanium nitride is roughly 75 nanometers.
"Inspired, in part, by hard biological materials and by earlier work by Toby Schaedler and a team from HRL Laboratories, Caltech, and UC Irvine on the fabrication of extremely lightweight microtrusses, we designed architectures with building blocks that are less than five microns long, meaning that they are not resolvable by the human eye," says Julia R. Greer, professor of materials science and mechanics at Caltech. "Constructing these architectures out of materials with nanometer dimensions has enabled us to decouple the materials’ strength from their density and to fabricate so-called structural metamaterials which are very stiff yet extremely lightweight."
At the nanometer scale, solids have been shown to exhibit mechanical properties that differ substantially from those displayed by the same materials at larger scales. For example, Greer’s group has shown previously that at the nanoscale, some metals are about 50 times stronger than usual, and some amorphous materials become ductile rather than brittle. "We are capitalizing on these size effects and using them to make real, three-dimensional structures," Greer says.
Read the full article at: sciencedaily.com
Water Nanofilter ‘Could Cut Diarrhea-Related Deaths’
Researchers watch nanoparticles self-assemble for the very first time
Nano-Suit Protects Bugs From Space-Like Vacuums
Nanoparticles Are in Our Food, Clothing and Medicine -- And No One Knows for Sure How Dangerous They Might Be
Nanomaterial Can Stop a Speeding Bullet, Strengthen Soldiers’ Body Armor
Nanotechnology condoms could provide greater protection against HIV and Herpes
Britain: Nanoscale Energy Storage Material Under Development
Upsalite: Scientists make ’impossible material’... by accident
Quantum Computers Coming Soon? Metamaterials Used to Observe Photonic Spin
Supertough, Strong Nanofibers Developed
Latest News from our Front Page
Pressure from the United Patriots Front Stops Mosque Plan
Pressure from the United Patriots Front appears to have killed off a mosque development in Narre Warren North.
The City of Casey council now looks likely to withhold planning approval for the development in a special meeting set for Tuesday night.
A council report, to be considered by councillors on Tuesday, recommends that the approval be blocked.
The mosque opponents’ cause has been helped by councillor ...
Police face questions over the influence of the Freemasons
South Yorkshire Police today face questions over whether powerful 'secret society' the Freemasons held sway over the force at the time of Hillsborough.
Families of victims say that officers who were Masons were promoted into powerful positions despite being ill-equipped, including match commander David Duckenfield.
Duckenfield told the fresh inquests he had been a Freemason since 1975 and became head of his ...
England Bans its Own Flag to Avoid Offending Muslims
St. George's Cross "racist" towards immigrants
Government officials said their city was ‘too multicultural’ to celebrate St George’s Day, England’s version of the 4th of July.
The council said that displaying the English flag may have been seen as “racist” towards immigrants.
Half of Western European men descended from one Bronze Age ‘king’
Half of Western European men are descended from one Bronze Age ‘king’ who sired a dynasty of elite nobles which spread throughout Europe, a new study has shown.
The monarch, who lived around 4,000 years ago, is likely to have been one of the earliest chieftains to take power in the continent.
He was part of a new order which emerged in ...
"Local Residents" Are Filmed Stealing Dozens of Bottles of Water at London Marathon Stop
Editor's Comment: "Local" residents? Why bother blurring their faces? We know who they are.
London marathon runners were robbed of dozens of bottled waters when thieves raided a refreshment area armed with trolleys during today's race.
Nearby residents - including parents with children - were captured on camera piling up crates of free water handed out by volunteers during the 26-mile event.
|More News » |