Scientists discover diamonds can generate electricity

Researchers at the University of Hong Kong have found that ultrathin, flexible diamond membranes can generate electricity through a piezoelectric response, contradicting the long-held belief that diamond is non-piezoelectric. The discovery, led by Professor Zhiqin Chu and Professor Yuan Lin, challenges previous assumptions about diamond's use in engineering.

Previously considered impractical, the idea of generating electricity from diamond was long dismissed due to its classification as non-piezoelectric. To investigate, the HKU team used a novel edge exfoliation method to create an ultrathin, flexible polycrystalline diamond membrane. By bending this material, the researchers observed stable voltage signals, confirming that the diamond membrane itself was producing a piezoelectric response.

Detailed first-principles calculations revealed that the electrical effect arises from asymmetry at grain boundaries within the polycrystalline diamond, which separate the tiny diamond crystals. As the membrane bends, electrical charge polarization builds up at these boundaries, creating a voltage difference between the membrane's surfaces.

This finding has significant implications for medical devices, tiny power systems, and self-powered sensing technologies, as diamond's biocompatibility, chemical stability, and non-toxicity make it an attractive material for such applications.