(Inverse) In addition to being tough, diamonds are highly conductive when it comes to both electricity and heat. By creating stretchy diamonds in the lab, scientists hope to improve upon these features and get them into next-gen electronics — including quantum computer chips.
Diamond is not only the hardest material in nature, but is also an extreme electronic material with an ultrawide bandgap, exceptional carrier mobilities, and thermal conductivity. Straining diamond can push such extreme figures of merit for device applications.
Ju Li,  professor of Material Science and Engineering at the Massachusetts Institute of Technology, and  coauthor on the recent study published in Science explains the research. “The team microfabricated single-crystalline diamond bridge structures with ~1 micrometer length by ~100 nanometer width and achieved sample-wide uniform elastic strains under uniaxial tensile loading along the [100], [101], and [111] directions at room temperature. They demonstrated deep elastic straining of diamond microbridge arrays. The ultralarge, highly controllable elastic strains can fundamentally change the bulk band structures of diamond, including a substantial calculated bandgap reduction as much as ~2 electron volts.”
The demonstration highlights the immense application potential of deep elastic strain engineering for photonics, electronics, and quantum information technologies.
“This is an active field of research,” Li says. “[But] strain engineering can be very powerful.” The researchers set out to test how much they could strain single-crystalline diamonds grown in their lab could sustain using something called a nanoindenter — essentially, a microscopic battering ram.
They found increased strain on these diamonds resulted in a corresponding decrease in internal energy — transforming them into a direct-bandgap superconductor — a characteristic which will ultimately play an important role in enabling these materials to be incorporated into microelectronic mechanical systems, including light or quantum-based electronics.