Wrap your smartphone around your wrist soon

Imagine wrapping your phone around your wrist when you go for a jog or folding your computer to fit in a pocket.

Researchers from South Korea have taken a new step toward more bendable devices by manufacturing a thin film that keeps its useful electric and magnetic properties even when highly curved - paving the way for potential uses in wearable devices.

A team of physicists and engineers from South Korea took the same approach with bismuth ferrite (BiFeO3) -- one of the most promising materials whose electronic properties can be controlled by a magnetic field and vice versa.

Such materials are called multiferroics and attract interest for applications like energy efficient, instant-on computing.

The researchers synthesised nanoparticles of bismuth ferrite and mixed them into a polymer solution.

The solution was dried in a series of steps at increasing temperatures to produce a thin, flexible film.

When the researchers tested the electric and magnetic properties of the film, they found that their new material did much more than preserving the useful properties of bulk bismuth ferrite -- it actually made them better.

The improved properties remained even as the film was curved into a cylindrical shape.

"Bulk bismuth ferrite has crucial problems for some applications such as a high leakage current which hinders the strong electric properties," said YoungPak Lee, professor at the Hanyang University in Seoul, South Korea.
Flexible multiferrorics could enable new wearable devices such as health monitoring equipment or virtual reality attire.

These materials could be used in high-density, energy efficient memory and switches in such devices, he noted.

The paper was published in the journal Applied Physics Letters.