What about machines that supply themselves with energy? For this purpose, devices in their surroundings would have to convert existing radiation, vibrations or heat into electricity. Engineers are presently studying how sensors might be operated by this so-called energy harvesting. Sensors measuring pressure or temperature ensure safe operation of production facilities all around the clock. Mostly, these measurement instruments are still operated with batteries. This results in a high maintenance expenditure. Moreover, the spent batteries pollute the environment. Scientists of the KIT Institute of Microstructure Technology (IMT) have developed an energy converter that converts waste heat into electricity. The key component of the energy converter is a thin, about 4 mm long and 2 mm wide strip made of a special metal alloy. When temperature changes by a few degrees Celsius, properties of this alloy change spontaneously. At ambient temperature, the metal strip is magnetic. When it is heated, it becomes non-magnetic and assumes a so-called shape memory form. The metal strip is fixed at one end, while the other end remains movable. First, the metal strip is deflected by a magnet and it gets into contact with the heat source, e.g. a hot pipeline. As a result of heating, the metal strip becomes non-magnetic and assumes its initial shape with the help of the shape memory force. Afterwards, the metal cools down and becomes magnetic again. The process is started anew. The metal strip rapidly moves upwards and downwards and starts to oscillate. When a small coil is fixed to the movable end of the metal strip, it swings into and out of the magnetic field. As a result, an electric current and, hence, electricity is induced in the coil. In practice it is reasonable to arrange several energy converters e.g. along a pipeline and connect them in parallel. KIT looks for partners for the further development of this technology and its use in practice.
Your contact person for this offer
Innovation Manager Energy Karlsruhe Institute of Technology (KIT)
Innovation and Relations Management (IRM) Phone: +49 721 608-25335