7-volt switch strains sapphire thousands of times its depth

Researchers at the US Department of Energy's Argonne National Laboratory found that a 7-volt pulse applied to a vanadium dioxide film strains the sapphire substrate tens of micrometers deep — thousands of times the film's thickness. Published in Science, the finding challenges the view of substrates as passive supports.

• 7-volt pulse strains sapphire tens of micrometers deep
• Effect reaches thousands of times the VO2 film thickness
• Distortion exceeds what heating alone could explain
• Result held across multiple devices, films and substrates