Japanese scientists at Ritsumeikan University have developed a urine-powered sensor that can alert caregivers when a diaper is wet.
The setup contains a battery attached to capacitor that stores generated electricity and a transmitter which can beam signal to a receiver up to 16 feet away.
The team has reportedly been working on the diaper for a few years with the goal of caring for aging patients suffering from urinary incontinence. The developed a flexible embeddable battery and urine sensor for the diaper.
To develop the smart diaper, the scientists first created a urine sensor, but it was too rigid to embed into a diaper. Pushing forward, it took five years for scientists to develop a flexible embeddable battery and sensor they needed but the batteries contained a chemical unsafe for humans, and also their charging times varied. Finally, the most recent version of the diaper sensors, published last year in the IEEE Sensors Journal, were perfectly safe and working as per the overall idea.
The most important part of the sensor is its urine-activated battery. The urine acts as an electrolyte allowing current to flow from one electrode to the other. For testing purposes, the scientists embedded two flexible electrodes into a disposable diaper. Also, the battery is attached to a tiny capacitor to store the generated electricity and a transmitter which can beam its signal to a receiver up to sixteen feet away. The research paper also points out that the battery generates less than 100 microwatts of power which is not enough to electrocute the wearer. The team, after successful test results, intends to test the diaper on real people now.
Apart from this new diaper, there are some smart diapers available on the market including another Japanese team's disposable sensor diaper created back in 2014, and a QR-code based disposable diaper pad that checks for urinary tract infections.