Fuente: Wipo "Sensorization" Movable vehicular assembly including an electricity generating system includes a movable substrate such as a tire, a power generating system arranged on, in connection with or within the substrate and to generate energy from movement of the substrate, and a circuit coupled to the power generating system and including an energy storage device. The circuit is operable in an active mode when the substrate moves and the power generating system generates energy or the energy storage device contains energy for powering the circuit and in a passive mode when the substrate is not moving and the energy storage device does not contain sufficient energy to power the circuit. The circuit receives power to operate in the passive mode from a signal received by the circuit. Components which may be part of the circuit include a surface-acoustic-wave device and a radio-frequency identification device.