Water-based galvanic cell for powering of wireless sensors

Inhalt:
This article deals with the energy supply of wireless sensor nodes using a galvanic cell in which water (e.g. tap water or rainwater) is used as an electrolyte. The electrodes of the developed galvanic cell consist of a gold surface and a zinc foil, which are placed on the reverse side of the sensor board. In case of contact with water, a voltage of several 100 mV is generated between the electrodes. The self-discharge of a battery does not limit the service life of such a galvanic cell, so maintenance-free installation directly under the screed in the floor or roof area is possible. The developed sensor can be used as a wireless water leakage sensor in different building parts. An additional RF power supply is being implemented to test the sensor in its installed state to activate the sensor electronics.