Have you ever wished that, instead of having to get up off the couch to check your baby’s diaper to see if it’s wet, you could just get a notification on your smart phone? Well, now we’re one step closer to that (dystopian?) future. This study describes the creation of a sensor that consists of a urine-activated battery connected to a wireless transmitter. Combine it with the baby poop predictor and you’re good to go!
“A self-powered urinary incontinence sensor consisting of a flexible urine-activated battery and a wireless transmitter has been developed as an application for wireless biosensor networks. The flexible urine-activated battery is embedded in a disposal diaper and makes possible both the sensing of urine leakage and self-powered operation. An intermittent power-supply circuit that uses an electric double-layer capacitor (EDLC) with a small internal resistance suppresses the supply voltage drop due to the large internal resistance of the battery. This circuit supplies the power to a wireless transmitter. A 315-MHz-band wireless transmitter performs low-power operation. To verify the effectiveness of the circuit scheme, we fabricated a prototype sensor system. When 80 cc of urine is poured onto the diaper, the battery outputs a voltage of 1 V; and the sensor can transmit an ID signal over a distance of 5 m.”