Gen-next technology to print tiny phones into clothing

Your T-shirt is ringing! Scientists are working on a gen-next technology that could make cell phones so small, efficient and flexible that they could be printed on clothing.
Researchers from the Monash University, Australia, are investigating a new version of "spaser" technology that will allow the tiny printing to take place.
They modelled the world's first spaser (surface plasmon amplification by stimulated emission of radiation) to be made completely of carbon.
A spaser is effectively a nanoscale laser or nanolaser. It emits a beam of light through the vibration of free electrons, rather than the space-consuming electromagnetic wave emission process of a traditional laser.

Lead researcher Chanaka Rupasinghe said the modelled spaser design using carbon would offer many advantages.
"Other spasers designed to date are made of gold or silver nanoparticles and semiconductor quantum dots while our device would be comprised of a graphene resonator and a carbon nanotube gain element," Rupasinghe said.

"The use of carbon means our spaser would be more robust and flexible, would operate at high temperatures, and be eco-friendly.
"Because of these properties, there is the possibility that in the future an extremely thin mobile phone could be printed on clothing," said Rupasinghe.
Spaser-based devices can be used as an alternative to current transistor-based devices such as microprocessors, memory, and displays to overcome current miniaturising and bandwidth limitations, researchers said.

Researchers chose to develop the spaser using graphene and carbon nanotubes. They are more than a hundred times stronger than steel and can conduct heat and electricity much better than copper. They can also withstand high temperatures.
Their research showed for the first time that graphene and carbon nanotubes can interact and transfer energy to each other through light.
These optical interactions are very fast and energy-efficient, and so are suitable for applications such as computer chips.
"Graphene and carbon nanotubes can be used in applications where you need strong, lightweight, conducting, and thermally stable materials due to their outstanding mechanical, electrical and optical properties. They have been tested as nanoscale antennas, electric conductors and waveguides," Chanaka said.

Chanaka said a spaser generated high-intensity electric fields concentrated into a nanoscale space. These are much stronger than those generated by illuminating metal nanoparticles by a laser in applications such as cancer therapy.
The finding was published in the journal ACS Nano.