As you may know, crafting a katana is a delicate process that involves carefully constructing a razor-sharp high-carbon edge around a soft shock-absorbent core. One day though, smiths and forging fires could be replaced by electrode-wielding mad-scientists, with the technology to selectively harden and soften metal at will. At least that's what we envisioned when we read about Jörg Weißmüller's breakthrough research in the field of nanomaterials. The German scientist discovered that by placing precious metals in acid he could create tiny ducts through corrosion. Once those channels are flooded with a conductive liquid
