Search Results - "Wirges, W."

Glycerol as high-permittivity liquid filler in dielectric silicone elastomers by Mazurek, P., Yu, L., Gerhard, R., Wirges, W., Skov, A. L.

“…ABSTRACT A recently reported novel class of elastomers was tested with respect to its dielectric properties. The new elastomer material is based on a…”
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Polarization and Hysteresis in Tubular-Channel Fluoroethylenepropylene-Copolymer Ferroelectrets by Qiu, X., Wirges, W., Gerhard, R.

“…Polarization-vs.-applied-voltage hysteresis curves are recorded on tubular-channel fluoroethylene-propylene (FEP) copolymer ferroelectrets by means of a…”
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Controlled inflation of voids in cellular polymer ferroelectrets: Optimizing electromechanical transducer properties by Wegener, M., Wirges, W., Gerhard-Multhaupt, R., Dansachmüller, M., Schwödiauer, R., Bauer-Gogonea, S., Bauer, S., Paajanen, M., Minkkinen, H., Raukola, J.

“…When exposed to sufficiently high electric fields, polymer-foam electret materials with closed cells exhibit ferroelectric-like behavior and may therefore be…”
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Optimized Preparation of Elastically Soft, Highly Piezoelectric, Cellular Ferroelectrets from Nonvoided Poly(ethylene Terephthalate) Films by Wirges, W., Wegener, M., Voronina, O., Zirkel, L., Gerhard-Multhaupt, R.

“…Electrically charged cellular polymer films can exhibit very high piezoelectric activity and are therefore more and more often employed in advanced…”
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Piezoelectric Polyethylene Terephthalate (PETP) Foams - Specifically Designed and Prepared Ferroelectret Films by Wegener, M., Wirges, W., Gerhard-Multhaupt, R.

“…The ferroic and electroactive properties of the recently identified ferroelectrets are based on the quasi‐permanent internal electric charging of the cellular…”
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Physical foaming of fluorinated ethylene-propylene (FEP) copolymers in supercritical carbon dioxide: single-film fluoropolymer piezoelectrets by Voronina, O., Wegener, M., Wirges, W., Gerhard, R., Zirkel, L., Münstedt, H.

“…Cellular polymer foams with significant piezoelectric activity were prepared from fluorinated ethylene-propylene (FEP) copolymers. The required void structure…”
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Novel heat durable electromechanical film: processing for electromechanical and electret applications by Saarimaki, E., Paajanen, M., Savijarvi, A.-M., Minkkinen, H., Wegener, M., Voronina, O., Schulze, R., Wirges, W., Gerhard-Multhaupt, R.

“…New ferroelectrets were developed on the basis of foams from cyclo-olefin polymers and copolymers. The results obtained on the cyclo-olefin polymer foam…”
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3D High-resolution Mapping of Polarization Profiles in Thin Poly(vinylidenefluoride-trifluoroethylene) (PVDF-TrFE) Films Using Two Thermal Techniques by Pham, Cong-duc, Petre, Anca, Berquez, Laurent, Flores-Suarez, Rosaura, Mellinger, Axel, Wirges, Werner, Gerhard, Reimund

“…In this paper, two non-destructive thermal methods are used in order to determine, with a high degree of accuracy, three-dimensional polarization distributions…”
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Piezoelectric two-layer stacks of cellular polypropylene ferroelectrets: transducer response at audio and ultrasound frequencies by Wegener, M., Bergweiler, S., Wirges, W., Pucher, A., Tuncer, E., Gerhard-Multhaupt, R.

“…Piezoelectric cellular polypropylene films, so-called ferroelectrets, are assembled in a stack with two active transducer layers. The stack is characterized…”
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Influence of humidity on the electrical charging properties of cork agglomerates by Lança, M.C., Wirges, W., Neagu, E.R., Gerhard, R., Marat-Mendes, J.

“…Cork is a natural cellular and electrically insulating material which may have the capacity to store electric charges on or in its cell walls. Since natural…”
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Thermal-pulse tomography of polarization distributions in a cylindrical geometry by Suarez, R.F., Mellinger, A., Wegener, M., Wirges, W., Gerhard-Multhaupt, R., Rajeev Singh

“…Fast, three-dimensional polarization mapping in piezoelectric sensor cables was performed by means of the novel thermal-pulse tomography (TPT) technique with a…”
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Dielectric investigation of photoinduced chromophore degradation in nonlinear optical side-chain polymer electrets by Bauer-Gogonea, S., Bauer, S., Wirges, W., Gerhard-Multhaupt, R.

“…Organic materials with noncentrosymmetric chromophores are known to be susceptible to a number of photochemical processes, including reversible isomerization…”
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Polyethylene terephthalate (PETP) foams as ferroelectrets by Wegener, M., Wirges, W., Dietrich, J.P., Gerhard-Multhaupt, R.

“…Voided space-charge electrets represent a new class of piezoelectric materials, the so-called ferroelectrets. Several polymers are under investigation with…”
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Voided cyclo-olefin polymer films: ferroelectrets with high thermal stability by Wegener, M., Paajanen, M., Voronina, O., Schulze, R., Wirges, W., Gerhard-Multhaupt, R.

“…Recently, new ferroelectrets were developed from foams of polyethylene terephthalate and of cyclo-olefin polymers and copolymers. Here, we focus on…”
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Dielectric investigation of photo-induced chromophore degradation in nonlinear optical side-chain polymer electrets by Bauer-Gogonea, S., Bauer, S., Wirges, W., Gerhard-Multhaupt, R.

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Cellular polyethylene-naphthalate ferroelectrets: Foaming in supercritical carbon dioxide, structural and electrical preparation, and resulting piezoelectricity by Fang, P., Wegener, M., Wirges, W., Gerhard, R., Zirkel, L.

“…Polymer foams with electrically charged cellular voids, the so-called ferroelectrets, are soft piezoelectric transducer materials. Several polymers such as…”
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Scanning electro-optical and pyroelectrical microscopy for the investigation of polarization patterns in poled polymers by YILMAZ, S, BAUER, S, WIRGES, W, GERHARD-MULTHAUPT, R

“…Compact and simple experimental setups for scanning pyroelectrical and electro-optical microscopy are introduced. Their feasibility is demonstrated with scans…”
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Selective poling of nonlinear optical polymer films by means of a monoenergetic electron beam by Yang, G.-M., Bauer-Gogonea, S., Sessler, G. M., Bauer, S., Ren, W., Wirges, W., Gerhard-Multhaupt, R.

“…Electron beams with an energy of 10 keV were employed for selectively poling only the lower part of a typical nonlinear optical guest/host polymer at a…”
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Polymer waveguides with optimized overlap integral for modal dispersion phase-matching by Wirges, W., Yilmaz, S., Brinker, W., Bauer-Gogonea, S., Bauer, S., Jäger, M., Stegeman, G. I., Ahlheim, M., Stähelin, M., Zysset, B., Lehr, F., Diemeer, M., Flipse, M. C.

“…Modal dispersion phase-matched second harmonic generation is demonstrated in new poled polymer waveguide geometries with a nonlinear optical core consisting of…”
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Ferroelectrets: adjustment of electric, elastic and piezoelectric properties by means of foam-structure modification by Wegener, M., Wirges, W., Mellinger, A., Winkler, M., Gerhard-Multhaupt, R.

“…In ferroelectrets, the piezoelectricity is based on bipolar charging of voids in the foam structure, which then represent (macroscopic) dipoles. It was found…”
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