Super Strong Material

A team of researchers have created a new, super-strong material by adding metal ions to spider webs.

The team – from the Max Planck Institute of Microstructure Physics – believe it may be possible to strengthen other fibres in a similar fashion. In addition to being stronger than natural web material, it also has the ability to be stretched further.

Commenting on the development Mato Knez, who is leading the team, said: “Our work promises great potential in terms of practical applications, as many other biomaterials can be made more break-resistant and ductile using our method.” Following from this, the team have used the process to strengthen fibres made of the protein collagen, an essential part of skin and bone in the human body. To infiltrate the fibres, the researchers employed a modified version of the technique of atomic layer deposition (ALD), previously only used for coating rather than infiltrating fibres.

Taken from latestengineeringnews

Self Healing Concentres

A team of US engineers have come up with a form of concrete that can repair cracks by itself. All the material needs, the team claim, is water and carbon dioxide.

The concrete is designed to crack in small hairline fractures, rather than splitting with wide gaps, like traditional concrete.

Explaining the process, Victor Li, the E. Benjamin Wylie Collegiate Professor of Civil Engineering, commented: “It’s like if you get a small cut on your hand, your body can heal itself. But if you have a large wound, your body needs help. You might need stitches. We’ve created a material with such tiny crack widths that it takes care of the healing by itself. Even if you overload it, the cracks stay small.”

Tests on the material showed that it recovered nearly all it’s strength after a 3 per cent tensile strain, which means that the concrete was stretched to 3 per cent bigger than its normal size. This is significant enough strain to fracture tradition concrete or deform metal.

“We found, to our happy surprise, that when we load it again after it heals, it behaves just like new, with practically the same stiffness and strength. Self-healing of crack damage recovers any stiffness lost when the material was damaged and returns it to its pristine state. The material can be damaged and still remain safe to load,” explained Li.

“Our hope is that when we rebuild our roads and bridges, we do it right, so that this transportation infrastructure does not have to undergo the expensive repair and rebuilding process again in another five to 10 years,” he concluded.

Taken from latestengineeringnews