Translating rotary motion to linear motion is a basic part of mechatronic design. Take a look at the nearest 3D-printer or CNC router — at least the Cartesian variety — and you’ll see some mechanism ...

Inventors have designed tiny, spinning screws that could drill into tumours and kill them. Kazushi Ishiyama at Tohoku University in Japan has invented prototypes of the tiny micromachines. The screws ...