US Patent 7967214 Card configured to receive separate battery

An electronic card comprises a thin, flexible substrate having electrical circuitry embedded therein. An activation device is disposed in the substrate and is configured to complete a circuit in response to a stimulus, such as light or sound. An output device is disposed in the substrate and is configured to produce an output, such as music or vibration, wherein the output device is activated upon the completion of the circuit by the activation device. A cavity is formed in an outer surface of the substrate and has electrical contacts at an inner portion thereof in electrical communication with the electrical circuitry. The cavity further comprises retaining means for replaceably retaining a battery in the cavity to enable the battery to provide power to the electrical circuitry, the activation device, and the output device. The retaining means allows a battery to be removed from the cavity and replaced with another battery.