Researchers at the University of Hong Kong have overturned a century-old scientific consensus by demonstrating that diamond, when processed into an ultrathin membrane, exhibits piezoelectric properties. This discovery challenges the long-standing assumption that diamond is fundamentally non-piezoelectric, revealing that mechanical deformation in these thin structures can generate stable electrical voltage. The research team, led by Professor Zhiqin Chu and Professor Yuan Lin, utilized an innovative edge-exfoliation method to create flexible polycrystalline diamond membranes. By subjecting these membranes to controlled mechanical strain, they observed consistent electrical output, confirming that the effect is intrinsic to the material's structure rather than environmental interference. The underlying mechanism for this phenomenon is attributed to asymmetrical grain boundaries within the polycrystalline diamond. As the membrane bends, charge accumulates at these interfaces, creating a voltage difference between the surfaces. This breakthrough shifts the perception of diamond from a purely structural, non-conductive platform to a potential active component in electronic systems. This finding holds significant practical value for the development of next-generation microelectromechanical systems (MEMS). Due to diamond's biocompatibility and chemical stability, these piezoelectric membranes are ideal for future implantable medical devices, self-powered sensors, and miniature energy harvesting systems that operate without external power sources.
