In the last years the legionella count in drinking water increasingly raised due to the use of energy-saving touch-free faucets.
A possible colonization of Legionella can be reduced by flushing the water lines between two faucets. For intelligent flushing a communication between the faucets is necessary.
For this purpose, a local autonomous power supply of the faucets like a thermoelectric energy harvester is required.
In this context, the focus lies on the research of printing different conductive materials like Nano Carbon Black and Nano Silver to produce inkjet-printed low-cost thermocouples which can be later used for energy harvesting.
Alternatively, RF based energy harvesters which are using the environment as energy source are in the field of research.
In Figure 1 a passive transceiver is shown. It harvests the energy from the environment and transmits measurement data back to a gateway.