Researchers at the Massachusetts Institute of Technology have invented a disposable diaper that automatically detects wetness caused by urine and alerts caregivers that it's time for changing. A press release describes how it works:
The sensor consists of a passive radio frequency identification (RFID) tag, that is placed below a layer of super absorbent polymer, a type of hydrogel that is typically used in diapers to soak up moisture. 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 1 meter away.
The researchers say the design is the first demonstration of hydrogel as a functional antenna element for moisture sensing in diapers using RFID. They estimate that the sensor costs less than 2 cents to manufacture, making it a low-cost, disposable alternative to other smart diaper technology.
-via Walyou | Image: MIT