The Internet of Things (IoT) — a term that encompasses everything “smart” or connected to the internet — has already crept into many aspects of our daily activities.

Now, it’s reached diapers.

The diaper change — a given of parenthood. Parents must check diapers at all times and change whenever necessary. But that might become a little easier thanks to a new sensor.

MIT researchers want to revolutionize diapers with a curious system of “smart” labels capable of warning caregivers when they detect a certain degree of moisture around them.

The invention is basically an alert system based on a sensor. It yses an absorbent hydrogel capable that changes its electrical conductivity when it gets wet, expanding and allowing a passive radio frequency identification (RFID) tag placed under it to transmit a wireless signal to a reader located within a 1-meter radius.

This RFID signal reader then sends a notice to the parents’ smartphone, letting them know that a diaper change is due.

Simply put, it’s a diaper alarm.

The idea is not new, but unlike previous attempts, it doesn’t require batteries in the RFID transmitter thanks to the hydrogel system. Furthermore, it is much cheaper: according to its creators each sensor would cost about two cents, which would allow them to be easily installed both in diapers as in other household objects to detect humidity. According to the researchers, this is the first-time hydrogel is proved to work as an antenna for moisture sensing in diapers.

Most diapers found now in stores have strips that indicate the level of wetness, changing their color accordingly. To step it up, companies are working to develop new wireless wetness sensors that attach to the diaper with a battery. Such sensors would cost over 40 dollars, much more expensive than the MIT alternative.

The new invention was tested by placing a tag within the bottom layers of a diaper and then wrapping the diaper to a doll – which was filled by saltwater. The dolls were placed at different distances from the RFID reader, proving the sensor activated and communicated with the reader when the diaper was wet. The system seemed to work in all situations, without any noticeable issues.

The sensor developed by MIT may also be helpful to identify health problems like incontinence, they claimed. Nurses at neonatal units looking after many babies at the same time would find it especially useful and It could even be added into adult diapers and not just for babies, they argued.

“Diapers are used not just for babies, but for aging populations, or patients who are bedridden and unable to take care of themselves,” Pankhuri Sen, a research assistant at MIT said in a press release. “It would be convenient in these cases for a caregiver to be notified that a patient, particularly in a multibed hospital, needs changing.”

The research, published in the IEEE Sensors Journal, didn’t address how feasible it would be to recycle a diaper with the new sensors. A whopping 187 billion nappies are thrown away each year, but unlike bottles or cans, they are almost impossible to recycle.

Babies use between 2.500 and 3.000 diapers in just their first year of life, needing them until they are potty trained. Conventional-single use diapers are not biodegradable and are manufactured mainly with plastic-based ingredients. They can take up to 500 years to decompose in a landfill.

Researches have been long looking for alternatives to recycle diapers. For example, in Italy, a pilot plant was set up last year to recover the plastic elements from the diapers. The plant was backed-up by one of the world’s leading producers of disposable diapers.