Header logo is


2015


no image
XMCD studies of thin Co films on BaTiO3

Welke, M., Gräfe, J., Govind, R. K., Babu, V. H., Trautmann, M., Schindler, K., Denecke, R.

{Journal of Physics: Condensed Matter}, 27(32), IOP Publishing, Bristol, UK, 2015 (article)

mms

DOI [BibTex]

2015


DOI [BibTex]


no image
Low temperature X-ray imaging of magnetic flux patterns in high temperature superconductors

Stahl, C., Ruoß, S., Weigand, M., Bechtel, M., Schütz, G., Albrecht, J.

{Journal of Applied Physics}, 117(17), AIP Publishing, New York, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Formation of a quasi-solid structure by intercalated noble gas atoms in pores of CuI-MFU-4l metal-organic framework

Magdysyuk, O. V., Denysenko, D., Weinrauch, I., Volkmer, D., Hirscher, M., Dinnebier, R. E.

{Chemical Communications}, 51(4):714-717, Royal Society of Chemistry, Cambridge, UK, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Burst-mode manipulation of magnonic vortex crystals

Hänze, M., Adolff, C. F., Weigand, M., Meier, G.

{Physical Review B}, 91(10), American Physical Society, Woodbury, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Fabrication and X-ray testing of true kinoform lenses with high efficiencies

Keskinbora, K., Sanli, U., Grévent, C., Schütz, G.

{Proceedings of SPIE}, 9592, SPIE, Bellingham, Washington, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Focused ion beam micromachining enables novel optics for X-ray microscopy

Keskinbora, K., Sanli, U., Grévent, C., Hirscher, M., Schütz, G.

{Microscopy and Microanalysis}, 21(Suppl 3):1983-1984, Springer-Verlag New York, New York, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Selectable nanopattern arrays for nanolithographic imprint and etch-mask applications

Jeong, H., Mark, A. G., Lee, T., Son, K., Chen, W., Alarcón-Correa, M., Kim, I., Schütz, G., Fischer, P.

{Advanced Science}, 2(2), Wiley-VCH, Weinheim, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Grain boundaries as a source of ferromagnetism and increased solubility of Ni in nanograined ZnO

Straumal, B. B., Mazilkin, A. A., Protasova, S. G., Stakhanova, S. V., Straumal, P. B., Bulatov, M. F., Schütz, G., Tietze, T., Goering, E., Baretzky, B.

{Reviews on Advanced Materials Science}, 41, pages: 61-71, 2015 (article)

mms

[BibTex]

[BibTex]


no image
Gyrational modes of benzenelike magnetic vortex molecules

Adolff, C. F., Hänze, M., Pues, M., Weigand, M., Meier, G.

{Physical Review B}, 92(2), American Physical Society, Woodbury, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
"Job-Sharing" storage of hydrogen in Ru/Li2O nanocomposites

Fu, L., Tang, K., Oh, H., Kandavel, M., Bräuniger, T., Vinod Chandran, C., Menzel, A., Hirscher, M., Samuelis, D., Maier, J.

{Nano Letters}, 15(6):4170-4175, American Chemical Society, Washington, DC, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Overview of the multilayer-Fresnel zone plate and the kinoform lens development at MPI for Intelligent Systems

Sanli, U., Keskinbora, K., Grévent, C., Schütz, G.

{Proceedings of SPIE}, 9510, SPIE, Bellingham, Washington, 2015 (article)

mms

DOI [BibTex]


no image
Transition matrix elements for electron-phonon scattering: Phenomenological theory and ab initio electron theory

Illg, C., Haag, M., Müller, B. Y., Czycholl, G., Fähnle, M.

{Physical Review B}, 92(19), American Physical Society, Woodbury, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Phase evolution in single-crystalline LiFePO4 followed by in situ scanning X-ray microscopy of a micrometre-sized battery

Ohmer, N., Fenk, B., Samuelis, D., Chen, C., Maier, J., Weigand, M., Goering, E., Schütz, G.

{Nature Communications}, 6, Nature Publishing Group, London, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Nitrogen-rich covalent triazine frameworks as high-performance platforms for selective carbon capture and storage

Hug, S., Stegbauer, L., Oh, H., Hirscher, M., Lotsch, B. V.

{Chemistry of Materials}, 27(23):8001-8010, American Chemical Society, Washington, D.C., 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Multilayer Fresnel zone plates for X-ray microscopy

Sanli, U. T., Keskinbora, K., Grévent, C., Szeghalmi, A., Knez, M., Schütz, G.

{Microscopy and Microanalysis}, 21(Suppl 3):1987-1988, Springer-Verlag New York, New York, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Interfacial dominated ferromagnetism in nanograined ZnO: a \muSR and DFT study

Tietze, T., Audehm, P., Chen, Y., Schütz, G., Straumal, B. B., Protasova, S. G., Mazilkin, A. A., Straumal, P. B., Prokscha, T., Luetkens, H., Salman, Z., Suter, A., Baretzky, B., Fink, K., Wenzel, W., Danilov, D., Goering, E.

{Scientific Reports}, 5, pages: 8871-8876, Nature Publishing Group, London, UK, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Preparation of a ferromagnetic barrier in YBa2Cu3O7-delta thinner than the coherence length

Soltan, S., Albrecht, J., Goering, E., Schütz, G., Mustafa, L., Keimer, B., Habermeier, H.

{Journal of Applied Physics}, 118(22), AIP Publishing, New York, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Microanalytical methods for in-situ high-resolution analysis of rock varnish at the micrometer to nanometer scale

Macholdt, D. S., Jochum, K. P., Pöhlker, C., Stoll, B., Weis, U., Weber, B., Müller, M., Kapl, M., Buhre, S., Kilcoyne, A. L. D., Weigand, M., Scholz, D., Al-Amri, A. M., Andreae, M. O.

{Chemical Geology}, 411, pages: 57-68, Elsevier, Amsterdam, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Chemical composition, microstructure, and hygroscopic properties of aerosol particles at the Zotino Tall Tower Observatory (ZOTTO), Siberia, during a summer campaign

Mikhailov, E. F., Mironov, G. N., Pöhlker, C., Chi, X., Krüger, M., Shiraiwa, M., Förster, J., Pöschl, U., Vlasenko, S. S., Ryshkevich, T. I., Weigand, M., Kilcoyne, A. L. D., Andreae, M.

{Atmospheric Chemistry and Physics}, 15(15):8847-8869, European Geosciences Union, Katlenburg-Lindau, Germany, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Orbital reflectometry of PrNiO3/PrAlO3 superlattices

Wu, M., Benckiser, E., Audehm, P., Goering, E., Wochner, P., Christiani, G., Logvenov, G., Habermeier, H., Keimer, B.

{Physical Review B}, 91(19), American Physical Society, Woodbury, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Dynamic domain wall chirality rectification by rotating magnetic fields

Bisig, A., Mawass, M., Stärk, M., Moutafis, C., Rhensius, J., Heidler, J., Gliga, S., Weigand, M., Tyliszczak, T., Van Waeyenberge, B., Stoll, H., Schütz, G., Kläui, M.

{Applied Physics Letters}, 106(12), American Institute of Physics, Melville, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Imaging spin dynamics on the nanoscale using X-ray microscopy

Stoll, H., Noske, M., Weigand, M., Richter, K., Krüger, B., Reeve, R. M., Hänze, M., Adolff, C. F., Stein, F., Meier, G., Kläui, M., Schütz, G.

{Frontiers in Physics}, 3, Frontiers Media, Lausanne, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Unique high-temperature performance of highly consensed MnBi permanent magnets

Chen, Y., Gregori, G., Leineweber, A., Qu, F., Chen, C., Tietze, T., Kronmüller, H., Schütz, G., Goering, E.

{Scripta Materialia}, 107, pages: 131-135, Pergamon, Tarrytown, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Electrical determination of vortex state in submicron magnetic elements

Gangwar, A., Bauer, H. G., Chauleau, J., Noske, M., Weigand, M., Stoll, H., Schütz, G., Back, C. H.

{Physical Review B}, 91(9), American Physical Society, Woodbury, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Mechanisms for the symmetric and antisymmetric switching of a magnetic vortex core: Differences and common aspects

Noske, M., Stoll, H., Fähnle, M., Hertel, R., Schütz, G.

{Physical Review B}, 91(1), American Physical Society, Woodbury, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
High resolution, high efficiency mulitlayer Fresnel zone plates for soft and hard X-rays

Sanli, U., Keskinbora, K., Gregorczyk, K., Leister, J., Teeny, N., Grévent, C., Knez, M., Schütz, G.

{Proceedings of SPIE}, 9592, SPIE, Bellingham, Washington, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Macroscopic drift current in the inverse Faraday effect

Hertel, R., Fähnle, M.

{Physical Review B}, 91(2), American Physical Society, Woodbury, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Single-step 3D nanofabrication of kinoform optics via gray-scale focused ion beam lithography for efficient X-ray focusing

Keskinbora, K., Grévent, C., Hirscher, M., Weigand, M., Schütz, G.

{Advanced Optical Materials}, 3, pages: 792-800, WILEY-VCH Verlag GmbH Co. KGaA, Weinheim, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Band structure engineering of two-dimensional magnonic vortex crystals

Behncke, C., Hänze, M., Adolff, C. F., Weigand, M., Meier, G.

{Physical Review B}, 91(22), American Physical Society, Woodbury, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Towards denoising XMCD movies of fast magnetization dynamics using extended Kalman filter

Kopp, M., Harmeling, S., Schütz, G., Schölkopf, B., Fähnle, M.

{Ultramicroscopy}, 148, pages: 115-122, North-Holland, Amsterdam, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Magnetic moments induce strong phonon renormalization in FeSi

Krannich, S., Sidis, Y., Lamago, D., Heid, R., Mignot, J., von Löhneysen, H., Ivanov, A., Steffens, P., Keller, T., Wang, L., Goering, E., Weber, F.

{Nature Communications}, 6, Nature Publishing Group, London, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Perpendicular magnetisation from in-plane fields in nano-scaled antidot lattices

Gräfe, J., Haering, F., Tietze, T., Audehm, P., Weigand, M., Wiedwald, U., Ziemann, P., Gawronski, P., Schütz, G., Goering, E. J.

{Nanotechnology}, 26(22), IOP Pub., Bristol, UK, 2015 (article)

mms

DOI Project Page [BibTex]

DOI Project Page [BibTex]


no image
Theory of ultrafast demagnetization after femtosecond laser pulses

Fähnle, M., Illg, C., Haag, M., Teeny, N.

{Acta Physica Polonica A}, 127(2):170-175, Państwowe Wydawnictwo Naukowe, Warszawa, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Non-linear radial spinwave modes in thin magnetic disks

Helsen, M., Gangwar, Ajay, De Clercq, J., Vansteenkiste, A., Weigand, M., Back, C. H., Van Waeyenberge, B.

{Applied Physics Letters}, 106(3), American Institute of Physics, Melville, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Hydrogen isotope separation in metal-organic frameworks: Kinetic or chemical affinity quantum-sieving?

Savchenko, I., Mavrandonakis, A., Heine, T., Oh, H., Teufel, J., Hirscher, M.

{Microporous and Mesoporous Materials}, 216, pages: 133-137, Elsevier, Amsterdam, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
High-resolution dichroic imaging of magnetic flux distributions in superconductors with scanning x-ray microscopy

Ruoß, S., Stahl, C., Weigand, M., Schütz, G., Albrecht, J.

{Applied Physics Letters}, 106, American Institute of Physics, Melville, NY, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Preparation and characterisation of epitaxial Pt/Cu/FeMn/Co thin films on (100)-oriented MgO single crystals

Schmidt, M., Gräfe, J., Audehm, P., Phillipp, F., Schütz, G., Goering, E.

{Physica Status Solidi A}, 212(10):2114-2123, Wiley-VCH, Weinheim, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]


no image
Probing the magnetic moments of [MnIII6CrIII]3+ single-molecule magnets - A cross comparison of XMCD and spin-resolved electron spectroscopy

Helmstedt, A., Dohmeier, N., Müller, N., Gryzia, A., Brechling, A., Heinzmann, U., Hoeke, V., Krickemeyer, E., Glaser, T., Leicht, P., Fonin, M., Tietze, T., Joly, L., Kuepper, K.

{Journal of Electron Spectroscopy and Related Phenomena}, 198, pages: 12-19, Elsevier B.V., Amsterdam, 2015 (article)

mms

DOI [BibTex]

DOI [BibTex]

2014


no image
Wenn es was zu sagen gibt

(Klaus Tschira Award 2014 in Computer Science)

Trimpe, S.

Bild der Wissenschaft, pages: 20-23, November 2014, (popular science article in German) (article)

am ics

PDF Project Page [BibTex]

2014


PDF Project Page [BibTex]


Thumb xl cover acs ancac3 v008i009
Nanopropellers and Their Actuation in Complex Viscoelastic Media

Schamel, D., Mark, A. G., Gibbs, J. G., Miksch, C., Morozov, K. I., Leshansky, A. M., Fischer, P.

ACS Nano, 8(9):8794-8801, June 2014, Featured cover article. (article)

Abstract
Tissue and biological fluids are complex viscoelastic media with a nanoporous macromolecular structure. Here, we demonstrate that helical nanopropellers can be controllably steered through such a biological gel. The screw-propellers have a filament diameter of about 70 nm and are smaller than previously reported nanopropellers as well as any swimming microorganism. We show that the nanoscrews will move through high-viscosity solutions with comparable velocities to that of larger micropropellers, even though they are so small that Brownian forces suppress their actuation in pure water. When actuated in viscoelastic hyaluronan gels, the nanopropellers appear to have a significant advantage, as they are of the same size range as the gel’s mesh size. Whereas larger helices will show very low or negligible propulsion in hyaluronan solutions, the nanoscrews actually display significantly enhanced propulsion velocities that exceed the highest measured speeds in Newtonian fluids. The nanopropellers are not only promising for applications in the extracellular environment but small enough to be taken up by cells.

Featured cover article.

pf

Video - Helical Micro and Nanopropellers for Applications in Biological Fluidic Environments link (url) DOI [BibTex]


Thumb xl toc image
Circular polarization interferometry: circularly polarized modes of cholesteric liquid crystals

Sanchez-Castillo, A., Eslami, S., Giesselmann, F., Fischer, P.

OPTICS EXPRESS, 22(25):31227-31236, 2014 (article)

Abstract
We describe a novel polarization interferometer which permits the determination of the refractive indices for circularly-polarized light. It is based on a Jamin-Lebedeff interferometer, modified with waveplates, and permits us to experimentally determine the refractive indices n(L) and n(R) of the respectively left- and right-circularly polarized modes in a cholesteric liquid crystal. Whereas optical rotation measurements only determine the circular birefringence, i.e. the difference (n(L) - n(R)), the interferometer also permits the determination of their absolute values. We report refractive indices of a cholesteric liquid crystal in the region of selective (Bragg) reflection as a function of temperature. (C) 2014 Optical Society of America

pf

DOI [BibTex]

DOI [BibTex]


Thumb xl toc image
Self-Propelling Nanomotors in the Presence of Strong Brownian Forces

Lee, T., Alarcon-Correa, M., Miksch, C., Hahn, K., Gibbs, J. G., Fischer, P.

NANO LETTERS, 14(5):2407-2412, 2014 (article)

Abstract
Motility in living systems is due to an array of complex molecular nanomotors that are essential for the function and survival of cells. These protein nanomotors operate not only despite of but also because of stochastic forces. Artificial means of realizing motility rely on local concentration or temperature gradients that are established across a particle, resulting in slip velocities at the particle surface and thus motion of the particle relative to the fluid. However, it remains unclear if these artificial motors can function at the smallest of scales, where Brownian motion dominates and no actively propelled living organisms can be found. Recently, the first reports have appeared suggesting that the swimming mechanisms of artificial structures may also apply to enzymes that are catalytically active. Here we report a scheme to realize artificial Janus nanoparticles (JNPs) with an overall size that is comparable to that of some enzymes similar to 30 nm. Our JNPs can catalyze the decomposition of hydrogen peroxide to water and oxygen and thus actively move by self-electrophoresis. Geometric anisotropy of the Pt-Au Janus nanoparticles permits the simultaneous observation of their translational and rotational motion by dynamic light scattering. While their dynamics is strongly influenced by Brownian rotation, the artificial Janus nanomotors show bursts of linear ballistic motion resulting in enhanced diffusion.

pf

DOI [BibTex]


Thumb xl toc image
Shape control in wafer-based aperiodic 3D nanostructures

Hyeon-Ho, J., Mark, A. G., Gibbs, J. G., Reindl, T., Waizmann, U., Weis, J., Fischer, P.

NANOTECHNOLOGY, 25(23), 2014, Cover article. (article)

Abstract
Controlled local fabrication of three-dimensional (3D) nanostructures is important to explore and enhance the function of single nanodevices, but is experimentally challenging. We present a scheme based on e-beam lithography (EBL) written seeds, and glancing angle deposition (GLAD) grown structures to create nanoscale objects with defined shapes but in aperiodic arrangements. By using a continuous sacrificial corral surrounding the features of interest we grow isolated 3D nanostructures that have complex cross-sections and sidewall morphology that are surrounded by zones of clean substrate.

Cover article.

pf

DOI [BibTex]

DOI [BibTex]


no image
A Limiting Property of the Matrix Exponential

Trimpe, S., D’Andrea, R.

IEEE Transactions on Automatic Control, 59(4):1105-1110, 2014 (article)

am ics

PDF DOI [BibTex]

PDF DOI [BibTex]


no image
Event-Based State Estimation With Variance-Based Triggering

Trimpe, S., D’Andrea, R.

IEEE Transactions on Automatic Control, 59(12):3266-3281, 2014 (article)

am ics

PDF Supplementary material DOI Project Page [BibTex]

PDF Supplementary material DOI Project Page [BibTex]


Thumb xl pictire scallop
Swimming by reciprocal motion at low Reynolds number

Qiu, T., Lee, T., Mark, A. G., Morozov, K. I., Muenster, R., Mierka, O., Turek, S., Leshansky, A. M., Fischer, P.

NATURE COMMUNICATIONS, 5, 2014, Max Planck Press Release. (article)

Abstract
Biological microorganisms swim with flagella and cilia that execute nonreciprocal motions for low Reynolds number (Re) propulsion in viscous fluids. This symmetry requirement is a consequence of Purcell's scallop theorem, which complicates the actuation scheme needed by microswimmers. However, most biomedically important fluids are non-Newtonian where the scallop theorem no longer holds. It should therefore be possible to realize a microswimmer that moves with reciprocal periodic body-shape changes in non-Newtonian fluids. Here we report a symmetric `micro-scallop', a single-hinge microswimmer that can propel in shear thickening and shear thinning (non-Newtonian) fluids by reciprocal motion at low Re. Excellent agreement between our measurements and both numerical and analytical theoretical predictions indicates that the net propulsion is caused by modulation of the fluid viscosity upon varying the shear rate. This reciprocal swimming mechanism opens new possibilities in designing biomedical microdevices that can propel by a simple actuation scheme in non-Newtonian biological fluids.

Max Planck Press Release.

pf

Video - A Swimming Micro-Scallop Video - Winner of the Micro-robotic Design Challenge in Hamlyn Symposium on Medical Robotics DOI [BibTex]

Video - A Swimming Micro-Scallop Video - Winner of the Micro-robotic Design Challenge in Hamlyn Symposium on Medical Robotics DOI [BibTex]


Thumb xl toc image
Nanohelices by shadow growth

Gibbs, J. G., Mark, A. G., Lee, T., Eslami, S., Schamel, D., Fischer, P.

NANOSCALE, 6(16):9457-9466, 2014 (article)

Abstract
The helix has remarkable qualities and is prevalent in many fields including mathematics, physics, chemistry, and biology. This shape, which is chiral by nature, is ubiquitous in biology with perhaps the most famous example being DNA. Other naturally occurring helices are common at the nanoscale in the form of protein secondary structures and in various macromolecules. Nanoscale helices exhibit a wide range of interesting mechanical, optical, and electrical properties which can be intentionally engineered into the structure by choosing the correct morphology and material. As technology advances, these fabrication parameters can be fine-tuned and matched to the application of interest. Herein, we focus on the fabrication and properties of nanohelices grown by a dynamic shadowing growth method combined with fast wafer-scale substrate patterning which has a number of distinct advantages. We review the fabrication methodology and provide several examples that illustrate the generality and utility of nanohelices shadow-grown on nanopatterns.

pf

Video - Fabrication of Designer Nanostructures DOI [BibTex]


Thumb xl toc image
Chiral Nanomagnets

Eslami, S., Gibbs, J. G., Rechkemmer, Y., van Slageren, J., Alarcon-Correa, M., Lee, T., Mark, A. G., Rikken, G. L. J. A., Fischer, P.

ACS PHOTONICS, 1(11):1231-1236, 2014 (article)

Abstract
We report on the enhanced optical properties of chiral magnetic nanohelices with critical dimensions comparable to the ferromagnetic domain size. They are shown to be ferromagnetic at room temperature, have defined chirality, and exhibit large optical activity in the visible as verified by electron microscopy, superconducting quantum interference device (SQUID) magnetometry, natural circular dichroism (NCD), and magnetic circular dichroism (MCD) measurements. The structures exhibit magneto-chiral dichroism (MChD), which directly demonstrates coupling between their structural chirality and magnetism. A chiral nickel (Ni) film consisting of an array of nanohelices similar to 100 nm in length exhibits an MChD anisotropy factor g(MChD) approximate to 10(-4) T-1 at room temperature in a saturation field of similar to 0.2 T, permitting polarization-independent control of the film's absorption properties through magnetic field modulation. This is also the first report of MChD in a material with structural chirality on the order of the wavelength of light, and therefore the Ni nanohelix array is a metamaterial with magnetochiral properties that can be tailored through a dynamic deposition process.

pf

DOI [BibTex]

DOI [BibTex]


Thumb xl toc image
Wireless powering of e-swimmers

Roche, J., Carrara, S., Sanchez, J., Lannelongue, J., Loget, G., Bouffier, L., Fischer, P., Kuhn, A.

SCIENTIFIC REPORTS, 4, 2014 (article)

Abstract
Miniaturized structures that can move in a controlled way in solution and integrate various functionalities are attracting considerable attention due to the potential applications in fields ranging from autonomous micromotors to roving sensors. Here we introduce a concept which allows, depending on their specific design, the controlled directional motion of objects in water, combined with electronic functionalities such as the emission of light, sensing, signal conversion, treatment and transmission. The approach is based on electric field-induced polarization, which triggers different chemical reactions at the surface of the object and thereby its propulsion. This results in a localized electric current that can power in a wireless way electronic devices in water, leading to a new class of electronic swimmers (e-swimmers).

pf

DOI [BibTex]

DOI [BibTex]


Thumb xl toc image
Swelling and shrinking behaviour of photoresponsive phosphonium-based ionogel microstructures

Czugala, M., O’Connell, C., Blin, C., Fischer, P., Fraser, K. J., Benito-Lopez, F., Diamond, D.

SENSORS AND ACTUATORS B-CHEMICAL, 194, pages: 105-113, 2014 (article)

Abstract
Photoresponsive N-isopropylacrylamide ionogel microstructures are presented in this study. These ionogels are synthesised using phosphonium based room temperature ionic liquids, together with the photochromic compound benzospiropyran. The microstructures can be actuated using light irradiation, facilitating non-contact and non-invasive operation. For the first time, the characterisation of the swelling and shrinking behaviour of several photopatterned ionogel microstructures is presented and the influence of surface-area-to-volume ratio on the swelling kinetics is evaluated. It was found that the swelling and shrinking behaviour of the ionogels is strongly dependent on the nature of the ionic liquid. In particular, the {[}P-6,P-6,P-6,P-14]{[}NTf2] ionogel exhibits the greatest degree of swelling, reaching up to 180\% of its initial size, and the fastest shrinkage rate (k(sh) = 29 +/- 4 x 10(-2) s(-1)). (C) 2014 Elsevier B. V. All rights reserved.

pf

DOI [BibTex]

DOI [BibTex]