To make sheets of copper, the metal is heated in a furnace, then hammered and squeezed on a large anvil. It took his team seven years to adapt the concept to work at the nanoscale.

Unlike the Raw Copperphonic which has a dark, streaky patina, the Hammered Copperphonic is bright orange-brown, easily distinguishable from the also-available Hammered Brass Supraphonic, which is a ...