For over a century, diamond stood at the edge of possibility in materials science — exceptional in nearly every measurable way, yet barred from active electrical life by a classification that seemed unassailable. Researchers at the University of Hong Kong have now shown that ultrathin diamond membranes, bent with deliberate care, generate repeatable electrical voltage — a discovery that dissolves a hundred years of assumption and invites diamond into the living circuitry of modern engineering. The finding is less a technical correction than a philosophical one: what we call a material's nature