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Publications in Scientific Journals:

F. Maier, M. Schneider, P. Ullmann, J. Hafner, U. Schmid:
"α-phase PVDF MEMS cantilever excited by electrostriction and evaluated up to 160 °C in air by laser-Doppler vibrometry";
Journal of Applied Physics, 129 (2021), Artikel 214507; 1 - 8.



English abstract:
The electroactive polymer polyvinylidene fluoride (PVDF) has gained much interest in smart materials research with a wide application
range for industry and consumer applications due to the low cost, flexibility, chemical resistance, non-toxicity, and light weight. In this
work, we present an α-phase PVDF cantilever that exploits electrostriction as the main transducer mechanism for excitation. We realize
thin PVDF films with a thickness of ∼190 nm and a low roughness (∼19 nm RMS). Electrostrictive cantilevers need high electric fields to
achieve amplitudes comparable to piezoelectric counterparts. At thinner films, lower voltage levels are requested for comparable electric
fields, thus making electrostrictive PVDF cantilevers a viable route and subsequently allowing broader use of PVDF in MEMS devices.
We use an asymmetric electrode design that has the advantage of shifting the neutral axis out of the PVDF without enhancing cantilever
thickness with a supporting device layer. In addition, these devices can be produced by CMOS compatible micromachining techniques. We
measured the electrostrictive and piezoelectric actuation signal with laser-Doppler vibrometry and showed the frequency spectrum and
curvature of such α-phase PVDF cantilevers. The cantilevers have a curvate of up to 120 m−1 at 1500 kV/cm. We demonstrate that the
electrostrictive actuation has a low temperature dependency in the range from 25 up to 130 °C. A typical cantilever exhibits a geometry
dependent low spring constant (k ∼0.3 N m−1) and a low quality factor (Q ∼75) in air.


"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
http://dx.doi.org/10.1063/5.0051313


Created from the Publication Database of the Vienna University of Technology.