The current move towards wearables is surely good news for us, but unremittingly bad news for them. A flexible sensor developed at the University of Tokyo is about to discover just how bad when it's put to work as a sort of early warning system inside diapers. It's constructed from a printable organic circuit that detects changes in wetness, temperature and pressure, but apparently not smell (small mercies). It can charge wirelessly and transmit data wirelessly too, so that a caregiver holding a receiver can tell whether a baby or incontinent elderly person needs changing without having to unclothe them first. The device is expected to come to market as soon as its power efficiency has been improved, and we bet it can't wait.