According to the team, flexible electronics have been hard to manufacture because many materials with useful electronic properties tend to be rigid. The solution, says the team, is to take tiny bits of materials like silicon and embed them in flexible plastics.
However, rather than use silicon, the South Korean team has used bismuth ferrite – a multiferroic – whose electronic properties can be controlled by a magnetic field. Nanoparticles of bismuth ferrite were mixed in a polymer solution, which was dried to produce a thin, flexible film. When the film's electric and magnetic properties were tested, the team found the useful properties of bulk bismuth ferrite had been enhanced – and the improved properties remained when 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 Professor Young Pak Lee from Hanyang University. Mixing nanoparticles of bismuth ferrite into a polymer improved the current-leakage problem, he said, and gave the film flexible, stretchable properties.
Flexible multiferroics could enable new wearable devices such, as health monitoring equipment or virtual reality attire, said Prof Lee, adding the multiferroric materials could also be used in high density, energy efficient memory and switches.
