High tech fiber could be used as skin for ROBOTS! Engineers create wonder material with the strength of metal and the elasticity of rubber
- Researchers at North Carolina State University are behind the innovation
- Made fibers consisting of gallium metal core surrounded by elastic polymer
- The function is similar to the way human tissue holds together broken bones
Scientists have developed a fiber that combines the elasticity of rubber with the strength of a metal.
Researchers at North Carolina State University are behind the innovation, which has created a tougher material that could be incorporated into soft robotics, packaging materials or next-generation textiles.
The team made fibers consisting of a gallium metal core surrounded by an elastic polymer sheath. When placed under stress, the fiber has the strength of the metal core.
But whereas the metal eventually breaks, the fiber does not fail – the polymer sheath absorbs the strain between the breaks in the metal and transfers the stress back to the metal core. This response is similar to the way human tissue holds together broken bones.
The team made fibers consisting of a gallium metal core surrounded by an elastic polymer sheath – and, when placed under stress, the fiber has the strength of the metal core
Whereas the metal eventually breaks, the fiber does not fail – the polymer sheath absorbs the strain between the breaks in the metal and transfers the stress back to the metal core
'A good way of explaining the material is to think of rubber bands and metal wires,' says Professor Michael Dickey
'A rubber band can stretch very far, but it does not take much force to stretch it. Metal wire requires a lot of force to stretch it, but it can not take much strain – it breaks before you can stretch it very far. Our fibers have the best of both worlds. '
'Every time the metal core breaks it dissipates energy, allowing the fiber to continue to absorb energy as it elongates,' he adds.
'Instead of snapping in two when stretched, it can stretch up to seven times its original length before failure, while causing many additional breaks in the wire along the way.
'To think of it another way, the fiber will not snap and drop a heavy weight. Instead, by releasing energy repeatedly through internal breaks, the fiber lowers the weight slowly and steadily. '
In materials, toughness is a material's ability to absorb energy and deform without breaking. You can think of it as the amount of force a material can absorb as it is deformed over a distance.
The new fiber is far tougher than either the metal wire or the polymer sheath on its own.
Seen here withstanding considerable force, the tough material that could be incorporated into soft robotics, packaging materials or next-generation textiles
'There's a lot of interest in engineering materials to mimic the toughness of skin – and we have developed a fiber that has surpassed the toughness of skin yet is still elastic like skin,' Dickey says.
In addition, the gallium core is conductive – though it loses its conductivity when the internal core breaks. The fibers can also be reused by melting the metal cores back together.
'We used gallium for this proof of concept work, but the fibers could be tuned to alter their mechanical properties, or to retain functionality at higher temperatures, by using different materials in the core and shell. This is only a proof of concept, but it holds a lot of potential.
'We are interested to see how these fibers could be used in soft robotics or when woven into textiles for various applications.'
COULD AUTONOMOUS ROBOTS PAINT OUR HOMES?
US engineers have developed an autonomous robot that could one day paint people's walls.
Scientists behind the robot, named Maverick, claim that it can paint walls evenly and with striking accuracy.
MIST, or mobile intelligent spraying technologies, is the team behind the robot and is made up of engineering students from the University of Waterloo.
Maverick is equipped with an array of sensors that makes it a fully-functioning autonomous robot, MIST says.
The robot uses mapping technology and an elevator-like shaft to spray paint up and down the walls.
It's fitted with a platform, arm and spray system that allows for even coating.
MIST believes that the home painter industry is ripe for disruption, noting that there are over 5,000 painting-related injuries each year, with $ 1.5 billion spent on painters annually in North America.
'The traditional manual painting process is slow, costly, inefficient and hazardous,' MIST notes on its website.