From wisebrother.com:
This seems like one of those technologies that's TOTALLY UNNECESSARY . . . but would actually be pretty convenient if it went mainstream and was affordable.
Scientists from Penn State University have created a "smart diaper" . . . with a built-in sensor that's able to send parents a push notification on their phone when their child's diaper needs to be changed.
And not only that, but it can provide LEVELS OF DIRTINESS . . . maybe like, "There's a little tinkle" to "Holy hell you're gonna need gloves for this one!"
The smart diapers are made of paper, and include sodium chloride (salt) . . . graphite . . . a circuit board . . . and a tiny lithium battery.
Once it gets wet, the graphite reacts with the liquid and sodium chloride and . . . as it's absorbed by the paper, electrons will set off a sensor.
The diapers are still in the development stage . . . so it's unclear when they'd be available and, more importantly, how much they'd cost. So for now, you'll have to stick to checking the diaper yourself like usual.