One of the defining rituals of early parenthood – holding your baby’s backside in front of your face and going in search of trouble – might be on the way out.
US researchers have developed a smart nappy that sets off an alarm in your smartphone or computer in the instant the nappy is dampened or presumably dirtied (the press release delicately refrained from mentioning number twos).
The innovation comes from MIT – which also gave birth to the first computer game, the worldwide web, voice recognition technology, spreadsheets, disposable razors and GPS.
Sooner or later, technology was bound to replace a parent’s nostrils or squeezing ability.
How it works and why we need it
The nappy, courtesy of MIT engineers, is embedded with a passive radio frequency identification (RFID) tag.
This is placed below a layer of super-absorbent polymer, the hydrogel that is typically used in nappies to soak up urine and moisture from the other stuff.
When the hydrogel is wet, the material expands and becomes slightly conductive – enough to trigger the RFID tag to send a radio signal to an RFID reader up to one metre away.
The receiver in turn sends a notification to a smartphone or computer – where presumably one of the parents or professional care-giver is busily trawling the internet in search of distraction, or seeking advice on how to disappear and make a new life.
The researchers say the design is the first demonstration of hydrogel as a functional antenna element for moisture sensing in nappies using RFID.
They estimate that the sensor costs less than two cents to manufacture, “making it a low-cost, disposable alternative to other smart diapers“.
But seriously, there’s a sting in the tail
Some babies are happy to drag themselves around without complaint, even when their nappy seems to hang off them like a giant jellyfish.
But sooner or later, if left unattended, dirty nappies lead to red and raw rashes and a lot of howling and guilt.
The researchers suggest that “over time, smart diapers may help record and identify certain health problems, such as signs of constipation or incontinence”.
They also suggest the new sensor may be especially useful for nurses working in neonatal units and caring for multiple babies at a time.
Ms Pankhuri Sen is a research assistant in MIT’s AutoID Laboratory, and a graduate student in engineering and management.
She envisions that the sensor could also be integrated into adult nappies, for patients who might be unaware or too embarrassed to report themselves that a change is needed.
“Diapers are used not just for babies, but for ageing populations, or patients who are bedridden and unable to take care of themselves,” said Ms Sen in a prepared statement.
“It would be convenient in these cases for a caregiver to be notified that a patient, particularly in a multibed hospital, needs changing.”
Ma Sen said that companies looking into smart nappy technology are considering wetness sensors that are wireless or Bluetooth-enabled, with devices that attach to a nappy’s exterior, along with bulky batteries to power long-range connections to the internet.
These sensors are designed to be reusable, requiring a caregiver to remove and clean the sensor before attaching it to each new nappy.
Ms Sen estimated these sensors would retail for more than $US40 ($59.50).
Ms Sen and her collaborators have published a paper that details “design considerations for integration with manufacturing processes” and explores possible future applications enabled by hydrogel sensing.
But some commentators have questioned about the smartness of buying nappy smart technology. See here.