Parents will soon know when a diaper needs to be changed — before all the crying starts.
Scientists from Penn State University have created a “smart diaper” — a nappy with a built-in sensor that will send an alert to a phone once it gets wet.
The diaper is made out of paper that has been pre-treated with sodium chloride (salt) and has an outline of a circuit board on it that is traced over with a pencil to transfer graphite to the surface with a tiny lithium battery attached.
Researchers embedded four of the sensors between the layers of a diaper in order to create the “smart diaper,” as detailed in the journal Nano Letters.
Once the diaper gets wet, the graphite reacts with the liquid and sodium chloride and, as it’s absorbed by the paper, electrons will flow to the graphite to set off a sensor.
The sensor will send a message to a phone, alerting the person that the baby’s diaper needs to be changed.
It can even provide information about how wet the diaper is, which could let parents decide if the diaper needs to be changed immediately.
“That application was actually born out of personal experience,” lead author Dr. Huanyu Cheng, who is the father to two young children, said. “There’s no easy way to know how wet is wet, and that information could be really valuable for parents.”
The sensor can also be used in hospitals or nursing homes — and can even help discover some major health concerns such as cardiac arrest or pneumonia.
“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,” Huanyu said.
Researchers also tested the device in a face mask and found that it could determine three breathing states — deep, regular and rapid — and could potentially provide data that could detect the onset of a heart attack or when someone stops breathing.
It can also sense humidity changes in the air as part of a non-contact switch with the presence of a finger, without the finger actually touching the device.
“The atoms on the finger don’t need to touch the button, they only need to be near the surface to diffuse the water molecules and trigger the sensor,” Huanyu explained. “When we think about what we learned from the pandemic about the need to limit the body’s contact with shared surfaces, a sensor like this could be an important tool to stop potential contamination.”
While the device and phone app are both still in the developmental stage, the scientists hope the smart diaper will soon be made available to the public.