Volume 80, Issue 2 -

Condition-Monitoring is necessary for a state-based maintenance of machines and equipment. The ideal energy harvesting system operates maintenance free in a way that it can be really a “mount and forget” installation. It must cope with high standards in lifetime and reliability. Battery driven systems can usually not be employed due to the requirement for replacement as well as their toxic potential. In this paper we present energy-harvesting systems for the monitoring of machines or logistic processes.

The system design of a piezoelectric MEMS energy harvesting module based on analytical modelling is described. The application example of a wireless sensor node for tire pressure monitoring system (TPMS) is considered. System considerations comprise the generator design, material impact and the generator interface circuitry. A design procedure is presented, which allows to identify a suitable geometry design space for the piezoelectric microgenerator.

In RFID applications the power supply of transponders via electromagnetic field is state-of-the-art. In this presentation the use of electromagnetic energy will be discussed for the operation of sensor modules. Starting with the question, whether the omnipresent radiation from power supply networks, radio transmitters, and mobile phone base stations is useable (energy harvesting), the feasibility of the operation of self-sufficient sensor modules is explained. Ancillary conditions of typical applications (e. g. operating range) and technology are considered. Zusammenfassung In RFID-Anwendungen ist die Nutzung eines elektromagnetischen Feldes zur Versorgung des Transponders etabliert. Im Rahmen dieses Artikels wird die Nutzung des elektromagnetischen Feldes für den Betrieb von Sensormodulen diskutiert. Ausgehend von der Frage, ob die allgegenwärtige Umgebungsstrahlung vom Stromnetz sowie Radio- und Mobilfunkstrahlung nutzbar sind (Energy Harvesting), werden die Möglichkeiten zur Versorgung autarker Sensormodule erläutert. Dabei finden Randbedingungen aus typischen Anwendungen (Reichweite, Messgröße) und der Technologie (Antennen, Frequenzen) Berücksichtigung.

The screen printing technology enables the subsequent deposition of current collector, electrode and separator/electrolyte materials onto foil substrates to form flexible film batteries. This can be realized in single as well as in multicell (series connection) layout. Printed rechargeable Ni-MH cells are demonstrated here the first time, exhibiting capacities of 32 mAh with an active area of 20×20 mm 2 and an overall thickness of 0.6 mm appr. The sealing issue could be solved by applying a printable, heat activated glue layer. The long-term cycling proves the stability of the cells. A printable electrolyte/separator has been developed.