A.1 Electret-based Transducer
PhD Student: Simon Genter
Project A.2 deals with electret-basedmicrogenerators. Electrets are dielectric polymers which are able to store electrical charges quasi-permanently. With the help of the stored charges, variable capacitive structures of an oscillator can be biased. By vibrational excitation a movement of the integrated capacities occurs which leads to a compensation current. Thus, vibrational energy gets transduced into electrical energy.
Based on the previous work the micro-generator shall be optimized. Therefor it is aimed to suspend the seismic mass of the resonator with polymer-based springs made of Parylene-C with a concurrent non-linear behaviour. Thus resonant frequencies below 100 Hz for applications at the human body should be achieved. Furthermore the non-linear frequency response enables the generator to harvest energy from a wide range of frequencies.
Parylene-C can also be used as electret. For this purpose the long-term stability of the charges has to optimized by examining different charging parameters and layer thicknesses.
Finally all developments will be merged into a new generation of the generator, which will be characterized in detail in terms of frequency response and output power.
Flip-Chip bonded electret-based micro generator with a 2D oscillator
suspended by 7 µm thin silicon springs mounted to a DIL-28 carrier