Many technical systems work with air or water - air compression systems and water pipes are just two examples. Sensors constantly monitor the pressure of such systems to keep costly fault-related losses to a minimum. At present, these sensors are either battery-driven or connected up by complex technical wiring, making it difficult to install sensors in hard-to-reach places. Researchers of the Fraunhofer Technology Development Group TEG have now successfully managed to convert fluidic energy into electricity, enabling the production of energy- autonomous and thus low-maintenance sensors.
The fluid-electricity conversion takes place in a fixed housing, through which the medium is fed on a course similar to that of blood circulating in the heart. The Coandã effect causes the constant stream of fluid to oscillate. This produces a periodic pressure fluctuation in the feedback branches, which are coupled to piezoceramics. The piezoceramics convert the fluidic energy into electricity. The new technique can be applied to any system in which a fluid or a gas is guided through a fixed geometry - such as in supply networks or in medical engineering.