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2015


Methods of forming dry adhesive structures
Methods of forming dry adhesive structures

Sitti, M., Murphy, M., Aksak, B.

September 2015, US Patent 9,120,953 (patent)

Abstract
Methods of forming dry adhesives including a method of making a dry adhesive including applying a liquid polymer to the second end of the stem, molding the liquid polymer on the stem in a mold, wherein the mold includes a recess having a cross-sectional area that is less than a cross-sectional area of the second end of the stem, curing the liquid polymer in the mold to form a tip at the second end of the stem, wherein the tip includes a second layer stem; corresponding to the recess in the mold, and removing the tip from the mold after the liquid polymer cures.

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[BibTex]

2015


[BibTex]


Experimental investigation of optimal adhesion of mushroomlike elastomer microfibrillar adhesives
Experimental investigation of optimal adhesion of mushroomlike elastomer microfibrillar adhesives

Marvi, H., Song, S., Sitti, M.

Langmuir, 31(37):10119-10124, American Chemical Society, August 2015 (article)

Abstract
Optimal fiber designs for the maximal pull-off force have been indispensable for increasing the attachment performance of recently introduced gecko-inspired reversible micro/nanofibrillar adhesives. There are several theoretical studies on such optimal designs; however, due to the lack of three-dimensional (3D) fabrication techniques that can fabricate such optimal designs in 3D, there have not been many experimental investigations on this challenge. In this study, we benefitted from recent advances in two-photon lithography techniques to fabricate mushroomlike polyurethane elastomer fibers with different aspect ratios of tip to stalk diameter (β) and tip wedge angles (θ) to investigate the effect of these two parameters on the pull-off force. We found similar trends to those predicted theoretically. We found that β has an impact on the slope of the force-displacement curve while both β and θ play a role in the stress distribution and crack propagation. We found that these effects are coupled and the optimal set of parameters also depends on the fiber material. This is the first experimental verification of such optimal designs proposed for mushroomlike microfibers. This experimental approach could be used to evaluate a wide range of complex microstructured adhesive designs suggested in the literature and optimize them.

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DOI [BibTex]

DOI [BibTex]


Micro-fiber arrays with tip coating and transfer method for preparing same
Micro-fiber arrays with tip coating and transfer method for preparing same

Sitti, M., Washburn, N. R., Glass, P. S., Chung, H.

July 2015, US Patent 9,079,215 (patent)

Abstract
Present invention describes a patterned and coated micro- and nano-scale fibers elastomeric material for enhanced adhesion in wet or dry environments. A multi-step fabrication process including optical lithography, micromolding, polymer synthesis, dipping, stamping, and photopolymerization is described to produce uniform arrays of micron-scale fibers with mushroom-shaped tips coated with a thin layer of an intrinsically adhesive synthetic polymer, such as lightly crosslinked p(DMA-co-MEA).

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[BibTex]

[BibTex]


pH-taxis of biohybrid microsystems
pH-taxis of biohybrid microsystems

Zhuang, J., Carlsen, R. W., Sitti, M.

Scientific reports, 5, Nature Publishing Group, June 2015 (article)

Abstract
The last decade has seen an increasing number of studies developing bacteria and other cell-integrated biohybrid microsystems. However, the highly stochastic motion of these microsystems severely limits their potential use. Here, we present a method that exploits the pH sensing of flagellated bacteria to realize robust drift control of multi-bacteria propelled microrobots. Under three specifically configured pH gradients, we demonstrate that the microrobots exhibit both unidirectional and bidirectional pH-tactic behaviors, which are also observed in free-swimming bacteria. From trajectory analysis, we find that the swimming direction and speed biases are two major factors that contribute to their tactic drift motion. The motion analysis of microrobots also sheds light on the propulsion dynamics of the flagellated bacteria as bioactuators. It is expected that similar driving mechanisms are shared among pH-taxis, chemotaxis, and thermotaxis. By identifying the mechanism that drives the tactic behavior of bacteria-propelled microsystems, this study opens up an avenue towards improving the control of biohybrid microsystems. Furthermore, assuming that it is possible to tune the preferred pH of bioactuators by genetic engineering, these biohybrid microsystems could potentially be applied to sense the pH gradient induced by cancerous cells in stagnant fluids inside human body and realize targeted drug delivery.

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DOI Project Page [BibTex]

DOI Project Page [BibTex]


Structural optimization for flexure-based parallel mechanisms--Towards achieving optimal dynamic and stiffness properties
Structural optimization for flexure-based parallel mechanisms–Towards achieving optimal dynamic and stiffness properties

Lum, G. Z., Teo, T. J., Yeo, S. H., Yang, G., Sitti, M.

Precision Engineering, 42, pages: 195-207, Elsevier, May 2015 (article)

Abstract
Flexure-based parallel mechanisms (FPMs) are a type of compliant mechanisms that consist of a rigid end-effector that is articulated by several parallel, flexible limbs (a.k.a. sub-chains). Existing design methods can enhance the FPMs’ dynamic and stiffness properties by conducting a size optimization on their sub-chains. A similar optimization process, however, was not performed for their sub-chains’ topology, and this may severely limit the benefits of a size optimization. Thus, this paper proposes to use a structural optimization approach to synthesize and optimize the topology, shape and size of the FPMs’ sub-chains. The benefits of this approach are demonstrated via the design and development of a planar X − Y − θz FPM. A prototype of this FPM was evaluated experimentally to have a large workspace of 1.2 mm × 1.2 mm × 6°, a fundamental natural frequency of 102 Hz, and stiffness ratios that are greater than 120. The achieved properties show significant improvement over existing 3-degrees-of-freedom compliant mechanisms that can deflect more than 0.5 mm and 0.5°. These compliant mechanisms typically have stiffness ratios that are less than 60 and a fundamental natural frequency that is less than 45 Hz.

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DOI [BibTex]

DOI [BibTex]


Controlled surface topography regulates collective 3D migration by epithelial--mesenchymal composite embryonic tissues
Controlled surface topography regulates collective 3D migration by epithelial–mesenchymal composite embryonic tissues

Song, J., Shawky, J. H., Kim, Y., Hazar, M., LeDuc, P. R., Sitti, M., Davidson, L. A.

Biomaterials, 58, pages: 1-9, Elsevier, April 2015 (article)

Abstract
Cells in tissues encounter a range of physical cues as they migrate. Probing single cell and collective migratory responses to physically defined three-dimensional (3D) microenvironments and the factors that modulate those responses are critical to understanding how tissue migration is regulated during development, regeneration, and cancer. One key physical factor that regulates cell migration is topography. Most studies on surface topography and cell mechanics have been carried out with single migratory cells, yet little is known about the spreading and motility response of 3D complex multi-cellular tissues to topographical cues. Here, we examine the response to complex topographical cues of microsurgically isolated tissue explants composed of epithelial and mesenchymal cell layers from naturally 3D organized embryos of the aquatic frog Xenopus laevis. We control topography using fabricated micropost arrays (MPAs) and investigate the collective 3D migration of these multi-cellular systems in these MPAs. We find that the topography regulates both collective and individual cell migration and that dense MPAs reduce but do not eliminate tissue spreading. By modulating cell size through the cell cycle inhibitor Mitomycin C or the spacing of the MPAs we uncover how 3D topographical cues disrupt collective cell migration. We find surface topography can direct both single cell motility and tissue spreading, altering tissue-scale processes that enable efficient conversion of single cell motility into collective movement.

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DOI [BibTex]

DOI [BibTex]


Transfer Printing of Metallic Microstructures on Adhesion-Promoting Hydrogel Substrates
Transfer Printing of Metallic Microstructures on Adhesion-Promoting Hydrogel Substrates

Wu, H., Sariola, V., Zhu, C., Zhao, J., Sitti, M., Bettinger, C. J.

Advanced Materials, 27(22):3398-3404, April 2015 (article)

Abstract
Fabrication schemes that integrate inorganic microstructures with hydrogel substrates are essential for advancing flexible electronics. A transfer printing process that is made possible through the design and synthesis of adhesion-promoting hydrogels as target substrates is reported. This fabrication technique may advance ultracompliant electronics by melding microfabricated structures with swollen hydrogel substrates.

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DOI [BibTex]

DOI [BibTex]


Dry adhesives and methods for making dry adhesives
Dry adhesives and methods for making dry adhesives

Sitti, M., Murphy, M., Aksak, B.

March 2015, US Patent App. 14/625,162 (patent)

Abstract
Dry adhesives and methods for forming dry adhesives. A method of forming a dry adhesive structure on a substrate, comprises: forming a template backing layer of energy sensitive material on the substrate; forming a template layer of energy sensitive material on the template backing layer; exposing the template layer to a predetermined pattern of energy; removing a portion of the template layer related to the predetermined pattern of energy, and leaving a template structure formed from energy sensitive material and connected to the substrate via the template backing layer.

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[BibTex]

[BibTex]


Biomedical applications of untethered mobile milli/microrobots
Biomedical applications of untethered mobile milli/microrobots

Sitti, M., Ceylan, H., Hu, W., Giltinan, J., Turan, M., Yim, S., Diller, E.

Proceedings of the IEEE, 103(2):205-224, IEEE, March 2015 (article)

Abstract
Untethered robots miniaturized to the length scale of millimeter and below attract growing attention for the prospect of transforming many aspects of health care and bioengineering. As the robot size goes down to the order of a single cell, previously inaccessible body sites would become available for high-resolution in situ and in vivo manipulations. This unprecedented direct access would enable an extensive range of minimally invasive medical operations. Here, we provide a comprehensive review of the current advances in biomedical untethered mobile milli/microrobots. We put a special emphasis on the potential impacts of biomedical microrobots in the near future. Finally, we discuss the existing challenges and emerging concepts associated with designing such a miniaturized robot for operation inside a biological environment for biomedical applications.

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DOI [BibTex]

DOI [BibTex]


Collective 3D Migration of Embryonic Epithelial Mesenchymal Composite Tissues are Regulated by Surface Topology
Collective 3D Migration of Embryonic Epithelial Mesenchymal Composite Tissues are Regulated by Surface Topology

Song, J., Shawky, J., Kim, Y. T., Hazar, M., Sitti, M., LeDuc, P. R., Davidson, L. A.

Biophysical Journal, 108(2):455a, Elsevier, January 2015 (article)

Abstract
Cells in tissues encounter a range of physical cues as they migrate. Probing single cell and collective migratory responses to physically defined three-dimensional (3D) microenvironments and the factors that modulate those responses are critical to understanding how tissue migration is regulated during development, regeneration, and cancer. One key physical factor that regulates cell migration is topology. Most studies on surface topology and cell mechanics have been carried out with single migratory cells, yet little is known about the spreading and motility response of 3D complex multicellular tissues to topological cues. Here, we examine the behaviors of microsurgically isolated tissue explants composed of epithelial and mesenchymal cell layers from naturally 3D organized embryos of the aquatic frog Xenopus laevis to complex topological cues. We control topology using fabricated micropost arrays (MPAs) with different diameters (e.g., different spacing gaps) and investigate the collective 3D migration of these multicellular systems in these MPAs. Our topographical controlled approach for cellular application enables us to achieve a high degree of control over micropost positioning and geometry via simple, accurate, and repeatable microfabrication processes. We find that the topology regulates both collective and individual cell migration and that dense MPAs reduce but do not eliminate tissue spreading. By modulating cell size through the cell cycle inhibitor Mitomycin C or the spacing within MPAs we discover a role for topology in disrupting collective enhancement of cell migration. We find 3D topological cues can direct both single cell motility and tissue spreading, altering tissue-scale processes that enable efficient conversion of single cell motility into collective movement.

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DOI [BibTex]

DOI [BibTex]


Three-dimensional heterogeneous assembly of coded microgels using an untethered mobile microgripper
Three-dimensional heterogeneous assembly of coded microgels using an untethered mobile microgripper

Chung, S. E., Dong, X., Sitti, M.

Lab on a Chip, 15(7):1667-1676, Royal Society of Chemistry, January 2015 (article)

Abstract
Three-dimensional (3D) heterogeneous assembly of coded microgels in enclosed aquatic environments is demonstrated using a remotely actuated and controlled magnetic microgripper by a customized electromagnetic coil system. The microgripper uses different ‘stick–slip’ and ‘rolling’ locomotion in 2D and also levitation in 3D by magnetic gradient-based pulling force. This enables the microrobot to precisely manipulate each microgel by controlling its position and orientation in all x–y–z directions. Our microrobotic assembly method broke the barrier of limitation on the number of assembled microgel layers, because it enabled precise 3D levitation of the microgripper. We used the gripper to assemble microgels that had been coded with different colours and shapes onto prefabricated polymeric microposts. This eliminates the need for extra secondary cross-linking to fix the final construct. We demonstrated assembly of microgels on a single micropost up to ten layers. By increasing the number and changing the distribution of the posts, complex heterogeneous microsystems were possible to construct in 3D.

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DOI Project Page [BibTex]

DOI Project Page [BibTex]


Integrating mechanism synthesis and topological optimization technique for stiffness-oriented design of a three degrees-of-freedom flexure-based parallel mechanism
Integrating mechanism synthesis and topological optimization technique for stiffness-oriented design of a three degrees-of-freedom flexure-based parallel mechanism

Lum, G. Z., Teo, T. J., Yang, G., Yeo, S. H., Sitti, M.

Precision Engineering, 39, pages: 125-133, Elsevier, January 2015 (article)

Abstract
This paper introduces a new design approach to synthesize multiple degrees-of-freedom (DOF) flexure-based parallel mechanism (FPM). Termed as an integrated design approach, it is a systematic design methodology, which integrates both classical mechanism synthesis and modern topology optimization technique, to deliver an optimized multi-DOF FPM. This design approach is separated into two levels. At sub-chain level, a novel topology optimization technique, which uses the classical linkage mechanisms as DNA seeds, is used to synthesize the compliant joints or limbs. At configuration level, the optimal compliant joints are used to form the parallel limbs of the multi-DOF FPM and another stage of optimization was conducted to determine the optimal space distribution between these compliant joints so as to generate a multi-DOF FPM with optimized stiffness characteristic. In this paper, the design of a 3-DOF planar motion FPM was used to demonstrate the effectiveness and accuracy of this proposed design approach.

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DOI [BibTex]


Actively controlled fibrillar friction surfaces
Actively controlled fibrillar friction surfaces

Marvi, H, Han, Y, Sitti, M

Applied Physics Letters, 106(5):051602, AIP Publishing, January 2015 (article)

Abstract
In this letter, we propose a technique by which we can actively adjust frictional properties of elastic fibrillar structures in different directions. Using a mesh attached to a two degree-of-freedom linear stage, we controlled the active length and the tilt angle of fibers, independently. Thus, we were able to achieve desired levels of friction forces in different directions and significantly improve passive friction anisotropies observed in the same fiber arrays. The proposed technique would allow us to readily control the friction anisotropy and the friction magnitude of fibrillar structures in any planar direction.

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DOI [BibTex]

DOI [BibTex]


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Structures of simple liquids in contact with nanosculptured surfaces

Singh, S. L., Schimmele, L., Dietrich, S.

Physical Review E, 91(3), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Line contribution to the critical Casimir force between a homogeneous and a chemically stepped surface

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

Journal of Physics: Condensed Matter, 27(21), IOP Publishing, Bristol, UK, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Self-propulsion of a catalytically active particle near a planar wall: from reflection to sliding and hovering

Uspal, W. E., Popescu, M. N., Dietrich, S., Tasinkevych, M.

Soft Matter, 11(3):434-438, Royal Society of Chemistry, Cambridge, UK, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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A size dependent evaluation of the cytotoxicity and uptake of nanographene oxide

Mendes, R. G., Koch, B., Bachmatiuk, A., Ma, X., Sanchez, S., Damm, C., Schmidt, O. G., Gemming, T., Eckert, J., Rümmeli, M. H.

Journal of Materials Chemistry B, 3(12):2522-2529, Royal Society of Chemistry, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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A bio-catalytically driven Janus mesoporous silica cluster motor with magnetic guidance

Ma, X., Sanchez, S.

Chemical Communications, 51(25):5467-5470, Royal Society of Chemistry, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Sperm Dynamics in Tubular Confinement

Magdanz, V., Koch, B., Sanchez, S., Schmidt, O. G.

Small, 11(7):781-785, Wiley Online Library, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Chromatic patchy particles: Effects of specific interactions on liquid structure

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

Physical Review E, 92(1), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Monte Carlo study of anisotropic scaling generated by disorder

Vasilyev, O., Berche, B., Dudka, M., Holovatch, Y.

Physical Review E, 92(4), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Fluctuations and diffusion in sheared athermal suspensions of deformable particles

Gross, M., Krüger, T., Varnik, F.

EPL, 108(6), IoPP, Bristol, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Enzyme-Powered Hollow Mesoporous Janus Nanomotors

Ma, Xing, Jannasch, Anita, Albrecht, Urban-Raphael, Hahn, Kersten, Miguel-Lopéz, Albert, Schäfer, Erik, Sanchez, Samuel

Nano Letters, 15(10):7043-7050, American Chemical Society, Washington, DC, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Interaction between colloidal particles on an oil\textendashwater interface in dilute and dense phases

Parolini, L., Cicuta, A. D. P., Law, A. D., Maestro, A., Buzza, M. A.

Journal of Physics: Condensed Matter, 27(19), IOP Publishing, Bristol, UK, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Anomalous Magnetotransport in Disordered Structures: Classical Edge-State Percolation

Schirmacher, Walter, Fuchs, Benedikt, Höfling, Felix, Franosch, Thomas

Physical Review Letters, 115, American Physical Society, Woodbury, N.Y., 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Precise Localization and Control of Catalytic Janus Micromotors using Weak Magnetic Fields

Khalil, I. S., Magdanz, V., Sanchez, S., Schmidt, O. G., Misra, S.

International Journal of Advanced Robotic Systems, 12, InTech, Rijeka, Croatia, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Nano-photocatalysts in microfluidics, energy conversion and environmental applications

Parmar, J., Jang, S., Soler, L., Kim, D., Sánchez, S.

Lab on a Chip, 15(11):2352-2356, Royal Society of Chemistry, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Static dielectric properties of dense ionic fluids

Zarubin, G., Bier, M.

The Journal of Chemical Physics, 142(18), American Institute of Physics, Woodbury, N.Y., 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Chemically Powered Micro-and Nanomotors

Sánchez, S., Soler, L., Katuri, J.

Angewandte Chemie, International Edition, 54(5):1414-1444, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, 2015 (article)

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[BibTex]

[BibTex]


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Convergence of large-deviation estimators

Rohwer, C. M., Angeletti, F., Touchette, H.

Physical Review E, 92(5), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Geometrically Tuned Channel Permeability

Malgaretti, P., Pagonabarraga, I., Rubi, J. M.

Macromolecular Symposia, 357(1):178-188, WILEY-VCH Verlag GmbH, Weinheim, Fed. Rep. of Germany, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Critical Casimir forces between planar and crenellated surfaces

Troendle, M., Harnau, L., Dietrich, S.

Journal of Physics: Condensed Matter, 27(21), IOP Publishing, Bristol, UK, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Theory of rheology in confinement

Aerov, A. A., Krüger, M.

Physical Review E, 92(4), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Implications of interface conventions for morphometric thermodynamics

Reindl, A., Bier, M., Dietrich, S.

Physical Review E, 91(2), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Linked topological colloids in a nematic host

Martinez, A., Hermosillo, L., Tasinkevych, M., Smalyukh, I. I.

Proceedings of the National Academy of Sciences of the United States of America, 112(15):4546-4551, National Academy of Sciences, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Colloidal spirals in nematic liquid crystals

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

Soft Matter, 11, pages: 8758-8767, Royal Society of Chemistry, Cambridge, UK, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Rheotaxis of spherical active particles near a planar wall

Uspal, W. E., Popescu, M. N., Dietrich, S., Tasinkevych, M.

Soft Matter, 11(33):6613-6632, Royal Society of Chemistry, Cambridge, UK, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Applications of three-dimensional (3D) printing for microswimmers and bio-hybrid robotics

Stanton, M. M., Trichet-Paredes, C., Sanchez, S.

Lab on a Chip, 15(7):1634-1637, Royal Society of Chemistry, Cambridge, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Linear and nonlinear magnetic properties of ferrofluids

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

Physical Review E, 92(4), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Microfluidic-Assisted Fabrication of Flexible and Location Traceable Organo-Motor

Seo, K. D., Kwak, B. K., Sanchez, S., Kim, D. S.

IEEE Transactions on Nanobioscience, 14(3):298-304, IEEE, New York, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Tracer diffusion of hard-sphere binary mixtures under nano-confinement

Marconi, U., Malgaretti, P., Pagonabarraga, I.

The Journal of Chemical Physics, 143(18), American Institute of Physics, Woodbury, N.Y., 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Fluctuating multicomponent lattice Boltzmann model

Belardinelli, D., Sbragaglia, M., Biferale, L., Gross, M., Varnik, F.

Physical Review E, 91(2), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Phase diagram of fluid phases in He3\textminusHe4 mixtures

Farahmand Bafi, N., Maciolek, A., Dietrich, S.

Physical Review E, 91(2), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Three-body critical Casimir forces

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

Physical Review E, 91(4), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Thermal and structural properties of ionic fluids

Bartsch, H., Dannenmann, O., Bier, M.

Physical Review E, 91(4), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


Exciting Engineered Passive Dynamics in a Bipedal Robot
Exciting Engineered Passive Dynamics in a Bipedal Robot

Renjewski, D., Spröwitz, A., Peekema, A., Jones, M., Hurst, J.

{IEEE Transactions on Robotics and Automation}, 31(5):1244-1251, IEEE, New York, NY, 2015 (article)

Abstract
A common approach in designing legged robots is to build fully actuated machines and control the machine dynamics entirely in soft- ware, carefully avoiding impacts and expending a lot of energy. However, these machines are outperformed by their human and animal counterparts. Animals achieve their impressive agility, efficiency, and robustness through a close integration of passive dynamics, implemented through mechanical components, and neural control. Robots can benefit from this same integrated approach, but a strong theoretical framework is required to design the passive dynamics of a machine and exploit them for control. For this framework, we use a bipedal spring–mass model, which has been shown to approximate the dynamics of human locomotion. This paper reports the first implementation of spring–mass walking on a bipedal robot. We present the use of template dynamics as a control objective exploiting the engineered passive spring–mass dynamics of the ATRIAS robot. The results highlight the benefits of combining passive dynamics with dynamics-based control and open up a library of spring–mass model-based control strategies for dynamic gait control of robots.

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link (url) DOI Project Page [BibTex]

link (url) DOI Project Page [BibTex]


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Frenetic aspects of second order response

Basu, U., Krüger, M., Lazarescu, A., Maes, C.

Physical Chemistry Chemical Physics, 17(9):6653-6666, Royal Society of Chemistry, Cambridge, England, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Critical Casimir forces in the presence of random surface fields

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

Physical Review E, 91(3), American Physical Society, Melville, NY, 2015 (article)

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DOI [BibTex]

DOI [BibTex]


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Lab-in-a-tube systems as ultra-compact devices

Sanchez, S.

Lab chip, (3):610-613, 2015 (article)

Abstract
{In this Focus article, I will give an overview on the current and future interests of our multidisciplinary research group. One of our main interests is to develop highly integrated on-chip components towards ultra-compact devices for biosensing technologies (lab-in-a-tube). Our other activities are focused in developing self-powered devices that can generate either motion of a fluid or autonomous propulsion. We are particularly interested in three-dimensional (3D) nanofabrication technologies and stimuli responsive soft materials.}

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DOI [BibTex]

DOI [BibTex]


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Catalytic Mesoporous Janus Nanomotors for Active Cargo Delivery

Ma, X., Hahn, K., Sanchez, S.

Journal of the American Chemical Society, 137(15):4976-4979, ACS Publications, 2015 (article)

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DOI [BibTex]

DOI [BibTex]