International Team of Scientists Develop Smart Diaper That Alerts Parents When It Is Soiled and Needs to Be Changed
Not the first smart diaper to come along, but consumers seem unready for diapers that can flag urinary tract infections and other biomarkers usually tested by clinical laboratories
Will wonders never cease? For centuries, parents had only their own senses to determine when infants needed diaper changing. Today, however, caregivers can rely on “smart diapers” to send alerts when a diaper is soiled. Crying, smelly babies may no longer be the gold standard in diaper management. But are smart diapers practical?
Funded by the National Institutes of Health (NIH) and the National Science Foundation (NSF), Penn State’s new smart diaper is based on a simple pencil-on-paper design that utilizes an electrode sensor array treated with a sodium chloride solution that detects dampness when urine is present.
The sensor array is “so cheap and simple” it “could clear the way for wearable, self-powered health monitors for use not only in ‘smart diapers’ but also to predict major health concerns like cardiac arrest and pneumonia,” a Penn State new release noted.
However, clinical laboratory managers following similar developments probably know that this is not the first scientific effort to develop a smart diaper that uses some type of sensor to detect a biomarker and issue an alert to the wearer or caregivers.
For example, nine years ago, In “New ‘Smart Diaper’ Tests Baby’s Urine for Urinary Tract Infections, Dehydration, and Kidney Problems—then Alerts Baby’s Doctor,” Dark Daily reported on a digital smart diaper invented by New York startup Pixie Scientific that constantly monitors a baby’s health to detect urinary tract infections, kidney problems, or dehydration before the health issue escalates. That smart diaper also uses a smartphone app to send data to the baby’s doctor.
In this latest research effort, the scientists published their findings in the journal Nano Letters, titled, “Pencil-on-Paper Humidity Sensor Treated with NaCl Solution for Health Monitoring and Skin Characterization.”
“Our team has been focused on developing devices that can capture vital information for human health,” said Huanyu “Larry” Cheng, PhD (above), the James L. Henderson, Jr. Memorial Associate Professor of Engineering Science and Mechanics at Penn State in a news release. “The goal is early prediction for disease conditions and health situations, to spot problems before it is too late.” This is yet another example of how researchers are working to take more testing out of clinical laboratories and offer unique assays that can be used as wearables—whether as a diaper, a skin patch, or a smart watch. (Photo copyright: Penn State University.)
This Smart Diaper Is as Simple to Use as Paper and Pencil
The Penn State sensor array takes advantage of how paper naturally reacts to wetness and utilizes the graphite in pencil marking to interact with the water molecules and sodium chloride.
Once the water molecules are absorbed by the paper, the sodium chloride solution becomes ionized and electrons start to stream towards the graphite. This movement sets off the sensor, which is extremely sensitive to humidity. According to the study, the sensor can provide accurate readings over a wide range of humidity levels, from 5.6% to 90%.
“We wanted to develop something low-cost that people would understand how to make and use, and you can’t get more accessible than pencil and paper,” said Li Yang, PhD, a professor in the School of Artificial Intelligence at China’s Hebei University of Technology and one of the authors of the study, in the Penn State news release.
“You don’t need to have some piece of multi-million-dollar equipment for fabrication. You just need to be able to draw within the lines of a pre-drawn electrode on a treated piece of paper. It can be done simply and quickly.”
The diaper is connected to a tiny lithium battery. When the sensor recognizes an increase in humidity the battery powers transmission of the change to a smartphone via Bluetooth technology. This notification informs caregivers that it is time to change the diaper.
“That application was actually born out of personal experience,” explained Huanyu “Larry” Cheng, PhD, James L. Henderson, Jr. Memorial Associate Professor of Engineering Science and Mechanics at Penn State, one of the authors of the study and father to two young children. “There’s no easy way to know how wet is wet, and that information could be really valuable for parents. 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.”
Do Consumers Want Smart Diapers?
Research into such wearable sensors has been gaining momentum in the scientific community as a novel way to detect and deal with several medical conditions. The Penn State team hopes that devices such as their smart diaper can be used in the future to alert caregivers about the overall health of their children and clients.
“Our team has been focused on developing devices that can capture vital information for human health,” Cheng said. “The goal is early prediction for disease conditions and health situations, to spot problems before it is too late.”
Previous research teams have had similar smart diaper goals.
In “Researchers in Japan Have Developed a ‘Smart’ Diaper Equipped with a Self-powered Biosensor That Can Monitor Blood Glucose Levels in Adults,” we covered how a team of researchers at Tokyo University of Science (TUS) in Japan had developed a diaper that detects blood glucose levels in individuals living with diabetes, a debilitating illness.
However, these types of products have yet to gain significant popularity with consumers. Regardless, sales projections for smart diapers remain positive.
According to a MarketsandMarkets report, the smart diaper market, estimated to be $646 million (US) in 2021, is expected to surpass $1.5 billion by 2026. The demand for smart diapers, the report notes, is increasing due to:
- Growing elderly populations,
- Rising disposable incomes,
- Increasing personal hygiene awareness,
- Growing populations in emerging countries, and
- Expanding preference for advanced technology when it comes to health.
So, it’s uncertain if consumers are now ready for a device in their baby’s diaper telling them it’s time for a change. Regardless, researchers will likely continue developing tools that combine new diagnostics with existing products to help people better understand and monitor their health and the health of their loved ones.
Meanwhile, clinical laboratory managers and pathologists can remain on the alert for future published studies and press releases announcing new wearable items containing sensors, such as smart diapers. The unanswered question is whether both consumers and healthcare professionals will consider these novel inventions useful devices in the care of young and old alike.