An apparatus and a system for a smart diaper are described. These smart diapers include a disposable detection component and a reusable component including various processing circuitries. The disposable component can include a paper printed sensor pad. Paper printed sensor pads can provide for a wide detection area, and accurate determination of whether human waste is present in the diaper. Additionally, the sensor pad can determine the amount of waste exposed to the sensor pad. In certain embodiments, the sensor can also detect a temperature within the diaper. In some embodiments, the smart diapers can provide for location tracking of the wearer of the diaper, and provide notifications to the caretaker based on the location of the wearer. In some embodiments, the reusable component can be a small circular component which is mounted on the outside of the smart diapers.