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2018


Gait learning for soft microrobots controlled by light fields
Gait learning for soft microrobots controlled by light fields

Rohr, A. V., Trimpe, S., Marco, A., Fischer, P., Palagi, S.

In International Conference on Intelligent Robots and Systems (IROS) 2018, pages: 6199-6206, International Conference on Intelligent Robots and Systems 2018, October 2018 (inproceedings)

Abstract
Soft microrobots based on photoresponsive materials and controlled by light fields can generate a variety of different gaits. This inherent flexibility can be exploited to maximize their locomotion performance in a given environment and used to adapt them to changing environments. However, because of the lack of accurate locomotion models, and given the intrinsic variability among microrobots, analytical control design is not possible. Common data-driven approaches, on the other hand, require running prohibitive numbers of experiments and lead to very sample-specific results. Here we propose a probabilistic learning approach for light-controlled soft microrobots based on Bayesian Optimization (BO) and Gaussian Processes (GPs). The proposed approach results in a learning scheme that is highly data-efficient, enabling gait optimization with a limited experimental budget, and robust against differences among microrobot samples. These features are obtained by designing the learning scheme through the comparison of different GP priors and BO settings on a semisynthetic data set. The developed learning scheme is validated in microrobot experiments, resulting in a 115% improvement in a microrobot’s locomotion performance with an experimental budget of only 20 tests. These encouraging results lead the way toward self-adaptive microrobotic systems based on lightcontrolled soft microrobots and probabilistic learning control.

ics pf

arXiv IEEE Xplore DOI Project Page [BibTex]

2018


arXiv IEEE Xplore DOI Project Page [BibTex]


A machine from machines
A machine from machines

Fischer, P.

Nature Physics, 14, pages: 1072–1073, July 2018 (misc)

Abstract
Building spinning microrotors that self-assemble and synchronize to form a gear sounds like an impossible feat. However, it has now been achieved using only a single type of building block -- a colloid that self-propels.

pf

link (url) DOI [BibTex]

link (url) DOI [BibTex]


Colloidal Chemical Nanomotors
Colloidal Chemical Nanomotors

Alarcon-Correa, M.

Colloidal Chemical Nanomotors, pages: 150, Cuvillier Verlag, MPI-IS , June 2018 (phdthesis)

Abstract
Synthetic sophisticated nanostructures represent a fundamental building block for the development of nanotechnology. The fabrication of nanoparticles complex in structure and material composition is key to build nanomachines that can operate as man-made nanoscale motors, which autonomously convert external energy into motion. To achieve this, asymmetric nanoparticles were fabricated combining a physical vapor deposition technique known as NanoGLAD and wet chemical synthesis. This thesis primarily concerns three complex colloidal systems that have been developed: i)Hollow nanocup inclusion complexes that have a single Au nanoparticle in their pocket. The Au particle can be released with an external trigger. ii)The smallest self-propelling nanocolloids that have been made to date, which give rise to a local concentration gradient that causes enhanced diffusion of the particles. iii)Enzyme-powered pumps that have been assembled using bacteriophages as biological nanoscaffolds. This construct also can be used for enzyme recovery after heterogeneous catalysis.

pf

[BibTex]

[BibTex]


Soft Miniaturized Linear Actuators Wirelessly Powered by Rotating Permanent Magnets
Soft Miniaturized Linear Actuators Wirelessly Powered by Rotating Permanent Magnets

Qiu, T., Palagi, S., Sachs, J., Fischer, P.

In 2018 IEEE International Conference on Robotics and Automation (ICRA), pages: 3595-3600, May 2018 (inproceedings)

Abstract
Wireless actuation by magnetic fields allows for the operation of untethered miniaturized devices, e.g. in biomedical applications. Nevertheless, generating large controlled forces over relatively large distances is challenging. Magnetic torques are easier to generate and control, but they are not always suitable for the tasks at hand. Moreover, strong magnetic fields are required to generate a sufficient torque, which are difficult to achieve with electromagnets. Here, we demonstrate a soft miniaturized actuator that transforms an externally applied magnetic torque into a controlled linear force. We report the design, fabrication and characterization of both the actuator and the magnetic field generator. We show that the magnet assembly, which is based on a set of rotating permanent magnets, can generate strong controlled oscillating fields over a relatively large workspace. The actuator, which is 3D-printed, can lift a load of more than 40 times its weight. Finally, we show that the actuator can be further miniaturized, paving the way towards strong, wirelessly powered microactuators.

pf

link (url) DOI [BibTex]

link (url) DOI [BibTex]


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Pattern forming systems under confinement

Maihöfer, Michael

Universität Stuttgart, Stuttgart, 2018 (mastersthesis)

icm

[BibTex]

[BibTex]


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Effective interactions between colloidal particles in critical solvents

Labbe-Laurent, M.

Universität Stuttgart, Stuttgart, 2018 (phdthesis)

icm

link (url) DOI [BibTex]

link (url) DOI [BibTex]


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Non-equilibrium dynamics of a binary solvent around heated colloidal particles

Wilke, Moritz

Universität Stuttgart, Stuttgart, 2018 (mastersthesis)

icm

[BibTex]

[BibTex]


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Monte Carlo study of colloidal structure formation at fluid interfaces

Meiler, Tim

Universität Stuttgart, Stuttgart, 2018 (mastersthesis)

icm

[BibTex]

[BibTex]


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Electrolyte solutions and simple fluids at curved walls

Reindl, A.

Universität Stuttgart, Stuttgart, 2018 (phdthesis)

icm

link (url) DOI [BibTex]

link (url) DOI [BibTex]


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Surface structure of liquid crystals

Sattler, Alexander

Universität Stuttgart, Stuttgart, 2018 (mastersthesis)

icm

[BibTex]

[BibTex]


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Dynamics of an active particle in confined viscous flows

Pöhnl, Ruben

Universität Stuttgart, Stuttgart, 2018 (mastersthesis)

icm

[BibTex]

[BibTex]


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Electrostatic interaction between colloids with constant surface potentials at fluid interfaces

Bebon, Rick

Universität Stuttgart, Stuttgart, 2018 (mastersthesis)

icm

[BibTex]

[BibTex]

2008


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Entropic Forces on Bio-Molecules

Hansen-Goos, H.

Universität Stuttgart, Stuttgart, 2008 (phdthesis)

icm

link (url) [BibTex]

2008


link (url) [BibTex]


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Wetting of geometrically structured substrates

Marinescu, M.

Universität Stuttgart, Stuttgart, Germany, 2008 (mastersthesis)

icm

[BibTex]

[BibTex]


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Fluktuations- und Kapillarkräfte zwischen Kolloiden an fluiden Grenzflächen

Lehle, H.

Universität Stuttgart, Stuttgart, 2008 (phdthesis)

icm

link (url) [BibTex]

link (url) [BibTex]


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Microscopic calculation of line tensions

Merath, R.-J.

Universität Stuttgart, Stuttgart, 2008 (phdthesis)

icm

link (url) [BibTex]

link (url) [BibTex]


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Lattice model for fluid flow in narrow channels

Dotti, C.

Universität Stuttgart, Stuttgart, 2008 (phdthesis)

icm

[BibTex]

[BibTex]


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Critical Casimir forces

Mohry, T. F.

Universität Stuttgart, Stuttgart, 2008 (mastersthesis)

icm

[BibTex]

[BibTex]

2007


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Phase behavior and effective interactions in colloidal suspensions

Grodon, C.

Universität Stuttgart, Stuttgart, 2007 (phdthesis)

icm

link (url) [BibTex]

2007


link (url) [BibTex]


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The effect of capillary forces on adhesion of biological and artificial attachment devices

De Souza, E. J.

Universität Stuttgart, Stuttgart, 2007 (phdthesis)

icm

link (url) [BibTex]

link (url) [BibTex]


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Brownian dynamics in near surface flows

Almenar Egea, L.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

icm

[BibTex]

[BibTex]


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Single lamella crystals of polyethylene accessible by catalytic emulsion-polymerization

Weber, C. H. M., Chiche, A., Krausch, G., Rosenfeldt, S., Ballauff, M., Goettker-Schnetmann, I., Tong, Q., Mecking, S., Harnau, L.

In Polymeric Materials: Science \& Engineering, 97, pages: 133-134, 2007 (inproceedings)

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[BibTex]

[BibTex]

2005


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Interplay between geometry and fluid properties

König, P.-M.

Universität Stuttgart, Stuttgart, 2005 (phdthesis)

icm

link (url) [BibTex]

2005


link (url) [BibTex]


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Molecular dynamics of wet granular media

Goll, C.

Universität Stuttgart, Stuttgart, 2005 (mastersthesis)

icm

[BibTex]

[BibTex]


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Grenzflächenfluktuationen binärer Flüssigkeiten

Hiester, T.

Universität Stuttgart, Stuttgart, 2005 (phdthesis)

icm

link (url) [BibTex]

link (url) [BibTex]

2000


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Selbst- und Fremddiffusion in amorphem Si28C36N36 und Si3N4

Matics, S.

Universität Stuttgart, Stuttgart, 2000 (phdthesis)

icm

link (url) [BibTex]

2000


link (url) [BibTex]