TY - JOUR A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Optimizing dimensions of unipolar Teflon-FEP piezoelectrets with micro-system-technology JF - Journal of Physics: Conference Series N2 - In this work we present a new micro-system-technology based production process for unipolar ferroelectrets. Theoretical analysis of the influence of the air-gap size on the electric field distribution as well as on the induced charge on the electrodes shows superior performance of unipolar piezoelectrets with small air-gaps. For the production of these small air-gaps we developed a new design using a photoresist thermoforming master, an integrated micro-heater and shadow masks for metallization. Unipolar piezoelectrets produced with this technology exhibit increased d33-coefficients compared to designs in previous publications. These piezoelectrets are highly preferable for energy-harvesting applications, as they promise high electric power output. KW - Mikrosystemtechnik Y1 - 2017 VL - 2018 IS - 1052 SP - 1 EP - 4 ER - TY - CHAP A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Observation of Thermal Discharge in Nanopatterned Electrets by Kelvin-Probe-Microscopy T2 - 14th International Symposium on Elecrets, 2011, Montpellier, France KW - Elektret Y1 - 2014 SN - 978-1-4577-1023-0 SN - 2153-3253 SP - 149 EP - 150 ER - TY - CHAP A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Direct Visualisation of Stored Charges in PECVD ONO-Layers by Kelvin-Probe-Force-Microscopy T2 - 15th International Symposium on Electrets ISE KW - Kelvin-Sonde KW - Rasterkraftmikroskop Y1 - 2014 VL - 2014 CY - Baltimore, USA ER - TY - THES A1 - Emmerich, Florian T1 - Eigenschaften und Anwendungen von Dünnschicht-Elektretmaterialien KW - Dünnschichttechnik KW - Elektret Y1 - 2020 U6 - https://doi.org/10.25534/tuprints-00012056 ER - TY - JOUR A1 - Flachs, Dennis A1 - Emmerich, Florian A1 - Roth, Gian-Luca A1 - Hellmann, Ralf A1 - Thielemann, Christiane T1 - Laser-bonding of FEP/FEP interfaces for a flexiblemanufacturing process of ferroelectrets JF - Journal of Physics: Conference Series N2 - This paper presents an optimized laser-bonding process for piezoelectric energy-harvesters based on thin fluorinated-ethylene-propylene (FEP) foils, using an ultra-short-pulse(USP) laser. Due to the minimized thermal stress in the material during bonding, achieved bypulse durations of few picoseconds, we created seams down to 40μm width without generatingholes in the 12.5μm thick FEP-foils. Using a galvanometer scanning system allowed for fastbonding-speed up to several centimeters per second, making the process also suitable for largestructures and areas. The achieved bond strength of the seams under influence of shearingstress was examined using tensile testing, which showed a sufficient strength of about 25 % of the maximum strength of an unbonded, single layer of FEP. KW - Ultrakurzzeitlaser KW - Piezoelektrizität Y1 - 2019 U6 - https://doi.org/10.1088/1742-6596/1407/1/012107 VL - 1407 IS - 012107 SP - 1 EP - 5 ER - TY - JOUR A1 - Flachs, Dennis A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Fabrication process for FEP piezoelectrets based on photolithographically structured thermoforming templates JF - Microsystem Technologies N2 - Piezoelectrets fabricated from fluoroethylenepropylene (FEP)-foils have shown drastic increase of their piezoelectric properties during the last decade. This led to the development of FEP-based energy harvesters, which are about to evolve into a technology with a power-generation-capacity of milliwatt per square-centimeter at their resonance frequency. Recent studies focus on piezoelectrets with solely negative charges, as they have a better charge stability and a better suitability for implementation in rising technologies, like the internet of things (IOT) or portable electronics. With these developments heading towards applications of piezoelectrets in the near future, there is an urgent need to also address the fabrication process in terms of scalability, reproducibility and miniaturization. In this study, we firstly present a comprehensive review of the literature for a deep insight into the research that has been done in the field of FEP-based piezoelectrets. For the first time, we propose the employment of microsystem-technology and present a process for the fabrication of thermoformed FEP piezoelectrets based on thermoforming SU-8 templates. Following this process, unipolar piezoelectrets were fabri� cated with air void dimensions in the range of 300–1000 lm in width and approx. 90 lm in height. For samples with a void size of 1000 lm, a d33-coefficient up to 26,508 pC/N has been achieved, depending on the applied seismic mass. Finally, the properties as energy harvester were characterized. At the best, an electrical power output of 0.51 mW was achieved for an acceleration of 1 � g with a seismic mass of 101 g. Such piezoelectrets with highly defined dimensions show good energy output in relation to volume, with high potential for widespread applications. KW - Mikrosystemtechnik Y1 - 2022 UR - Microsystem Technologies https://doi.org/10.1007/s00542-022-05405-6 U6 - https://doi.org/doi.org/10.1007/s00542-022-05405-6 VL - 2022 IS - November SP - 0 EP - 0 ER -