A device (10) for converting a movement of a user into a voltage comprises a neck cord (20), a piezoelectric sensor (30) and a printed circuit board (40). The neck cord is coupled to the piezoelectric sensor and provides in use a pulling force that acts on the piezoelectric sensor in a first direction. The printed circuit board is electrically and mechanically coupled to the piezoelectric sensor. The weight of the printed circuit board cause in use a gravity force to act on the piezoelectric sensor in a second direction, which differs from the first direction such that the movement of the user (5) wearing the neck cord causes a change in the shape of the piezoelectric sensor which in response thereto generates the voltage. The voltage may be used as a supply source for an electrical component (41) mounted on the PCB, or may be used as a wake-up signal for an electrical component such as a processor (41) or an accelerometer.
