3D electronics are one of the current goals in the technology industries. But 3D objects take up a lot of space, especially in transport or storage situations where volume is money. So flatpacking is the answer – and what better way to avoid the need for complex instructions and tools at the assembly end than making circuits that fold themselves together when hot water is poured on them? The current implementation is simple, but it should scale down to nanotech sizes without too much trouble.