The smart nappy that sends a text when it needs changing

WHETHER it’s by touch or the dreaded sniff test, every parent has their own way of checking if a nappy needs changing.

But that could all soon be a thing of the past thanks to a new invention.

Scientists have created a ‘smart diaper’ – a nappy with an inbuilt sensor that sends a text alert to a phone when it gets wet.

The small device consists of paper that has been pre-treated with sodium chloride, and has an outline of a circuit board on it.

The circuit board is traced over with a pencil, transferring graphite to the surface, and a tiny lithium battery is attached to the device.

When the paper gets wet, the graphite reacts with the liquid and the sodium chloride. As water molecules are absorbed by the paper, electrons begin to flow to the graphite and set off a sensor, which sends a message to a phone. The technology can even indicate how wet the nappy is – letting parents know if it needs changing urgently.

Father-of-two Dr Huanyu Cheng, from Penn University in the US, told the journal Nano Letters that the invention was ‘born out of personal experience’.

He added: ‘The sensor can provide data in the short-term, to alert for diaper changes, but also in the long-term, to show patterns that can inform parents about the overall health of their child.’

The researchers said their sensor could also be used in hospitals and nursing homes.