Header logo is


2013


no image
Self-Propelled Micromotors for Cleaning Polluted Watter

Soler, L., Magdanz, V., Fomin, V. M., Sanchez, S., Schmidt, O. G.

ACS Nano, 11, pages: 9611-9620, American Chemical Society, Washington, DC, 2013 (article)

Abstract
We describe the use of catalytically self-propelled microjets (dubbed micromotors) for degrading organic pollutants in water via the Fenton oxidation process. The tubular micromotors are composed of rolled-up functional nanomembranes consisting of Fe/Pt bilayers. The micromotors contain double functionality within their architecture, i.e., the inner Pt for the self-propulsion and the outer Fe for the in situ generation of ferrous ions boosting the remediation of contaminated water.The degradation of organic pollutants takes place in the presence of hydrogen peroxide, which acts as a reagent for the Fenton reaction and as main fuel to propel the micromotors. Factors influencing the efficiency of the Fenton oxidation process, including thickness of the Fe layer, pH, and concentration of hydrogen peroxide, are investigated. The ability of these catalytically self-propelled micromotors to improve intermixing in liquids results in the removal of organic pollutants ca. 12 times faster than when the Fenton oxidation process is carried out without catalytically active micromotors. The enhanced reaction\textendashdiffusion provided by micromotors has been theoretically modeled. The synergy between the internal and external functionalities of the micromotors, without the need of further functionalization, results into an enhanced degradation of nonbiodegradable and dangerous organic pollutants at small-scale environments and holds considerable promise for the remediation of contaminated water.

icm

DOI [BibTex]

2013


DOI [BibTex]


no image
Stability of thin liquid films and sessile droplets under confinement

Dörfler, F., Rauscher, M., Dietrich, S.

Physical Review E, 88(1), American Physical Society, Melville, NY, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Nonequilibrium interfaces in colloidal fluids

Bier, M., Arnold, D.

Physical Review E, 88(6), American Physical Society, Melville, NY, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Colloidal particles at fluid interfaces: Effective interactions, dynamics and a gravitation\textendashlike instability

Bleibel, J., Dom\’\inguez, A., Oettel, M.

The European Physical Journal Special Topics, 222(11):3071-3087, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Anomalous transport in the crowded world of biological cells

Höfling, Felix, Franosch, Thomas

Reports on Progress in Physics, 76(4), IOP Pub., London, 2013, author: Höfling, Felix (article)

icm

link (url) DOI [BibTex]

link (url) DOI [BibTex]


no image
Flow pattern in the vicinity of self-propelling hot Janus particles

Bickel, T., Majee, A., Würger, A.

Physical Review E, 88(1), American Physical Society, Melville, NY, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Brownian motion of optically trapped ellipsoids

Dibak, Manuel

Universität Stuttgart, Stuttgart, 2013 (mastersthesis)

icm

[BibTex]

[BibTex]


no image
Nonequilibrium Critical Casimir Effect in Binary Fluids

Furukawa, A., Gambassi, A., Dietrich, S., Tanaka, H.

Physical Review Letters, 111(5), American Physical Society, Woodbury, N.Y., 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Many-body effects for critical Casimir forces

Gomes de Mattos, T., Harnau, L., Dietrich, S.

The Journal of Chemical Physics, 138(7), 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Propulsion Mechanism of Catalytic Microjet Engines

Magdanz, V., Fomin, V. M., Soler, L., Sanchez, S., Schmidt, O. G., Hippler, M.

IEEE Transactions on Robotics and Automation, pages: 40-48, IEEE, New York, NY, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Impedance spectroscopy of ions at liquid-liquid interfaces

Bier, M., Reindl, A.

Physical Review E, 88(5), American Physical Society, Melville, NY, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Precursors of order in aggregates of patchy particles

Vasilyev, O., Klumov, B. A., Tkachenko, A. V.

Physical Review E, 88(1), American Physical Society, Melville, NY, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Two-temperature Langevin dynamics in a parabolic potential

Dotsenko, V., Maciolek, Anna, Vasilyev, O., Oshanin, G.

Physical Review E, 87(6), American Physical Society, Melville, NY, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Critical Casimir forces between homogeneous and chemically striped surfaces

Parisen Toldin, F., Tröndle, M., Dietrich, S.

Physical Review E, 88, American Physical Society, Melville, NY, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Comparison between theory and simulations for the magnetization and the susceptibility of polydisperse ferrofluids

Szalai, I., Nagy, S., Dietrich, S.

Journal of Physics: Condensed Matter, 25(46), IOP Pub., Bristol, UK, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Thermal activation of catalytic microjets in blood samples using microfluidic chips.

Soler, L., Mart\’\inez-Cisneros, C., Swiersy, A., Sanchez, S., Schmidt, O. G.

Lab on a Chip, 13, pages: 4299-4303, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Phase behavior of colloidal suspensions with critical solvents

Mohry, T. F.

Universität Stuttgart, Stuttgart, 2013 (phdthesis)

icm

link (url) [BibTex]

link (url) [BibTex]


no image
Nematic liquid crystal boojums with handles on colloidal handlebodies

Liu, Q. K., Senyuk, B., Tasinkevych, M., Smalyukh, I. I.

Proceedings of the National Academy of Sciences of the United States of America, 110(23):9231-9236, National Academy of Sciences, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Critical Casimir torques and forces acting on needles in two spatial dimensions

Vasilyev, Oleg, Eisenriegler, E., Dietrich, Siegfried

Physical Review E, 88(1), American Physical Society, Melville, NY, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
AGILITY – Dynamic Full Body Locomotion and Manipulation with Autonomous Legged Robots

Hutter, M., Bloesch, M., Buchli, J., Semini, C., Bazeille, S., Righetti, L., Bohg, J.

In 2013 IEEE International Symposium on Safety, Security, and Rescue Robotics (SSRR), pages: 1-4, IEEE, Linköping, Sweden, 2013 (inproceedings)

mg

link (url) DOI [BibTex]

link (url) DOI [BibTex]


no image
Critical Casimir forces along the isofields

Zubaszewska, M., Maciolek, A., Drzewinski, A.

Physical Review E, 88(5), American Physical Society, Melville, NY, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Surface states and the Casimir interaction in the Ising model

Abraham, D. B., Maciolek, A.

Europhysics letters, 101(2), Editrice Compositori., Bologna, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Crystallization, structural diversity, and anisotropy effects in 2D arrays of icosahedral viruses

Fukuto, M., Nguyen, Q. L., Vasilyev, O., Mank, N., Washington-Huges, C. L., Kuzmenko, I., Checco, A., Mao, Y., Wang, Q., Yang, L.

Soft Matter, 9(40):9633-9642, Royal Society of Chemistry, Cambridge, UK, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Dynamics of nanodroplets on structured surfaces

Rauscher, M.

In Nanodroplets, 18, pages: 143-167, Lecture Notes in Nanoscale Science and Technology, Springer, New York, 2013 (incollection)

Abstract
Editors:Zhiming M. Wang

icm

DOI [BibTex]

DOI [BibTex]


no image
Dynamic arrest in model porous media-intermediate scattering functions

Spanner, Markus, Schnyder, Simon K., Höfling, Felix, Voigtmann, Thomas, Franosch, Thomas

Soft Matter, 9(5):1604-1611, Royal Society of Chemistry, Cambridge, UK, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Zweidimensionale Monte-Carlo-Gittersimulationen im muVT- und NpT-Ensemble

Kirn, Kai Ludwig

Universität Stuttgart, Stuttgart, 2013 (mastersthesis)

icm

[BibTex]

[BibTex]


no image
Linear response relations in fluctuational electrodynamics

Golyk, V. A., Krüger, Matthias, Kardar, M.

Physical Review B, 88(15), American Physical Society, Woodbury, NY, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Wetting Phenomena on the Nanometer Scale

Rauscher, M., Dietrich, S., Napiórkowski, M.

In Nanoscale Liquid Interfaces - Wetting, Patterning and Force Microscopy at the Molecular Scale, pages: 83-154, Pan Stanford Publishing Pte. Ltd., Singapore, 2013 (incollection)

icm

DOI [BibTex]

DOI [BibTex]


no image
Ideal Polyethylene Nanocrystals

Osichov, A., Rabe, C., Vogtt, K., Narayanan, T., Harnau, Ludger, Drechsler, M., Ballauff, M.

Journal of the American Chemical Society, 135(31):11645-11650, American Chemical Society, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Permittivity of an inhomogeneous dipolar lattice fluid

Schütz, Christian

Universität Stuttgart, Stuttgart, 2013 (mastersthesis)

icm

[BibTex]

[BibTex]


no image
Self-Assembly of Two-Dimensional Colloidal Clusters by Tuning the Hydrophobicity, Composition, and Packing Geometry

Law, A. D., Auriol, M., Smith, D., Horozov, T. S., Buzza, D. M. A.

Physical Review Letters, 110, American Physical Society., Woodbury, N.Y., etc., 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Geometry-Induced Superdiffusion in Driven Crowded Systems

Bénichou, O., Bodrova, A., Chakraborty, D., Illien, P., Law, A. D., Mej\’\ia-Monasterio, C., Oshanin, G., Voituriez, R.

Physical Review Letters, 111(26), American Physical Society, Woodbury, N.Y., 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Overshoots in stress-strain curves: Colloid experiments and schematic mode coupling theory

Amann, Christian P, Siebenbürger, Miriam, Krüger, Matthias, Weysser, Fabian, Ballauff, Matthias, Fuchs, Matthias

Journal of Rheology, 57, pages: 149-175, 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Wetting in electrolyte solutions

Ibagon, Ingrid, Bier, Markus, Dietrich, Siegfried

The Journal of Chemical Physics, 138(21), American Institute of Physics, Woodbury, N.Y., 2013 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Learning Objective Functions for Manipulation

Kalakrishnan, M., Pastor, P., Righetti, L., Schaal, S.

In 2013 IEEE International Conference on Robotics and Automation, IEEE, Karlsruhe, Germany, 2013 (inproceedings)

Abstract
We present an approach to learning objective functions for robotic manipulation based on inverse reinforcement learning. Our path integral inverse reinforcement learning algorithm can deal with high-dimensional continuous state-action spaces, and only requires local optimality of demonstrated trajectories. We use L 1 regularization in order to achieve feature selection, and propose an efficient algorithm to minimize the resulting convex objective function. We demonstrate our approach by applying it to two core problems in robotic manipulation. First, we learn a cost function for redundancy resolution in inverse kinematics. Second, we use our method to learn a cost function over trajectories, which is then used in optimization-based motion planning for grasping and manipulation tasks. Experimental results show that our method outperforms previous algorithms in high-dimensional settings.

am mg

link (url) DOI [BibTex]

link (url) DOI [BibTex]


no image
Using Torque Redundancy to Optimize Contact Forces in Legged Robots

Righetti, L., Buchli, J., Mistry, M., Kalakrishnan, M., Schaal, S.

In Redundancy in Robot Manipulators and Multi-Robot Systems, 57, pages: 35-51, Lecture Notes in Electrical Engineering, Springer Berlin Heidelberg, 2013 (incollection)

Abstract
The development of legged robots for complex environments requires controllers that guarantee both high tracking performance and compliance with the environment. More specifically the control of contact interaction with the environment is of crucial importance to ensure stable, robust and safe motions. In the following, we present an inverse dynamics controller that exploits torque redundancy to directly and explicitly minimize any combination of linear and quadratic costs in the contact constraints and in the commands. Such a result is particularly relevant for legged robots as it allows to use torque redundancy to directly optimize contact interactions. For example, given a desired locomotion behavior, it can guarantee the minimization of contact forces to reduce slipping on difficult terrains while ensuring high tracking performance of the desired motion. The proposed controller is very simple and computationally efficient, and most importantly it can greatly improve the performance of legged locomotion on difficult terrains as can be seen in the experimental results.

am mg

link (url) [BibTex]

link (url) [BibTex]


no image
Optimal distribution of contact forces with inverse-dynamics control

Righetti, L., Buchli, J., Mistry, M., Kalakrishnan, M., Schaal, S.

The International Journal of Robotics Research, 32(3):280-298, March 2013 (article)

Abstract
The development of legged robots for complex environments requires controllers that guarantee both high tracking performance and compliance with the environment. More specifically the control of the contact interaction with the environment is of crucial importance to ensure stable, robust and safe motions. In this contribution we develop an inverse-dynamics controller for floating-base robots under contact constraints that can minimize any combination of linear and quadratic costs in the contact constraints and the commands. Our main result is the exact analytical derivation of the controller. Such a result is particularly relevant for legged robots as it allows us to use torque redundancy to directly optimize contact interactions. For example, given a desired locomotion behavior, we can guarantee the minimization of contact forces to reduce slipping on difficult terrains while ensuring high tracking performance of the desired motion. The main advantages of the controller are its simplicity, computational efficiency and robustness to model inaccuracies. We present detailed experimental results on simulated humanoid and quadruped robots as well as a real quadruped robot. The experiments demonstrate that the controller can greatly improve the robustness of locomotion of the robots.1

am mg

link (url) DOI [BibTex]

link (url) DOI [BibTex]


no image
Controlled Reduction with Unactuated Cyclic Variables: Application to 3D Bipedal Walking with Passive Yaw Rotation

Gregg, R., Righetti, L.

IEEE Transactions on Automatic Control, 58(10):2679-2685, October 2013 (article)

Abstract
This technical note shows that viscous damping can shape momentum conservation laws in a manner that stabilizes yaw rotation and enables steering for underactuated 3D walking. We first show that unactuated cyclic variables can be controlled by passively shaped conservation laws given a stabilizing controller in the actuated coordinates. We then exploit this result to realize controlled geometric reduction with multiple unactuated cyclic variables. We apply this underactuated control strategy to a five-link 3D biped to produce exponentially stable straight-ahead walking and steering in the presence of passive yawing.

mg

link (url) DOI [BibTex]

link (url) DOI [BibTex]


no image
Learning Task Error Models for Manipulation

Pastor, P., Kalakrishnan, M., Binney, J., Kelly, J., Righetti, L., Sukhatme, G. S., Schaal, S.

In 2013 IEEE Conference on Robotics and Automation, IEEE, Karlsruhe, Germany, 2013 (inproceedings)

Abstract
Precise kinematic forward models are important for robots to successfully perform dexterous grasping and manipulation tasks, especially when visual servoing is rendered infeasible due to occlusions. A lot of research has been conducted to estimate geometric and non-geometric parameters of kinematic chains to minimize reconstruction errors. However, kinematic chains can include non-linearities, e.g. due to cable stretch and motor-side encoders, that result in significantly different errors for different parts of the state space. Previous work either does not consider such non-linearities or proposes to estimate non-geometric parameters of carefully engineered models that are robot specific. We propose a data-driven approach that learns task error models that account for such unmodeled non-linearities. We argue that in the context of grasping and manipulation, it is sufficient to achieve high accuracy in the task relevant state space. We identify this relevant state space using previously executed joint configurations and learn error corrections for those. Therefore, our system is developed to generate subsequent executions that are similar to previous ones. The experiments show that our method successfully captures the non-linearities in the head kinematic chain (due to a counterbalancing spring) and the arm kinematic chains (due to cable stretch) of the considered experimental platform, see Fig. 1. The feasibility of the presented error learning approach has also been evaluated in independent DARPA ARM-S testing contributing to successfully complete 67 out of 72 grasping and manipulation tasks.

am mg

link (url) DOI [BibTex]

link (url) DOI [BibTex]

2011


no image
Collective dynamics of colloids at fluid interfaces

Bleibel, J., Dominguez, A., Oettel, M., Dietrich, S.

European Physical Journal E, 34(11), 2011 (article)

icm

DOI [BibTex]

2011


DOI [BibTex]


no image
Anomalous transport of a tracer on percolating clusters

Spanner, M., Höfling, F., Schröder-Turk, G. E., Mecke, K., Franosch, T.

Journal of Physics: Condensed Matter, 23(23), 2011 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Dynamics of colloids in confined geometries

Almenar, L., Rauscher, M.

Journal of Physics: Condensed Matter, 23(18), 2011 (article)

icm

link (url) DOI [BibTex]

link (url) DOI [BibTex]


no image
The structure and melting transition of two-dimensional colloidal alloys

Law, A. D., Horozov, T. S., Buzza, D. M. A.

Soft Matter, 7(19):8923-8931, 2011 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Second harmonic light scattering from spherical polyelectrolyte brushes

Schürer, B., Hoffmann, M., Wunderlich, S., Harnau, L., Peschel, U., Ballauff, M., Peukert, W.

Journal of Physical Chemistry C, 115, pages: 18302-18309, 2011 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Simulation einer fast kritischen binären Flüssigkeit in einem Temperaturgradienten

Single, F.

Universität Stuttgart, Stuttgart, 2011 (mastersthesis)

icm

[BibTex]

[BibTex]


no image
Solvation forces in Ising films with long-range boundary fields: density-matrix renormalization-group study

Drzewinski, A., Maciolek, A., Barasinski, A.

Molecular Physics, 109(7-10):1133-1141, 2011 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Pulling and pushing a cargo with a catalytically active carrier

Popescu, M. N., Tasinkevych, M., Dietrich, S.

Europhysics Letters, 95(2), 2011 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Critical Casimir forces for Ising films with variable boundary fields

Vasilyev, O., Maciolek, A., Dietrich, S.

Physical Review E, 84(4), 2011 (article)

icm

DOI [BibTex]


no image
Study of \pi\pi correlations at LHC and RHIC energies in pp collisions within the quark-gluon string model

Nilsson, M. S., Bravina, L. V., Zabrodin, E. E., Malinina, L. V., Bleibel, J.

Physical Review D, 84(5), 2011 (article)

icm

DOI [BibTex]

DOI [BibTex]


no image
Micro-rheology on (polymer-grafted) colloids using optical tweezers

Gutsche, C., Elmahdy, M. M., Kegler, K., Semenov, I., Stangner, T., Otto, O., Ueberschär, O., Keyser, U. F., Krüger, M., Rauscher, M., Weeber, R., Harting, J., Kim, Y. W., Lobaskin, V., Netz, R., Kremer, F.

Journal of Physics: Condensed Matter, 23(18), IOP Publishing, Bristol, 2011 (article)

icm

DOI [BibTex]

DOI [BibTex]