Magnetic microrobots with addressable shape control Hen-Wei Huang; Sakar, Mahmut Selman; Riederer, Katharina ...
2016 IEEE International Conference on Robotics and Automation (ICRA),
05/2016
Conference Proceeding
Shape shifting soft microrobots are generated from self-folding hydrogel bilayer structures. The folding conditions are analyzed to develop an optimal strategy for producing desired three-dimensional ...shapes. We present two different methods for programming magnetization in these microrobots that are variant and invariant to folding. The microrobots can be navigated through user-defined trajectories using rotating magnetic fields, and the morphing in response to temperature changes can be tuned for adaptive behavior. On-demand modulation of the mobility of individual microrobots is demonstrated by morphing their shape using selective near infrared light (NIR) exposure.
"Heavy Metal Music and the Communal Experience critically examines the issue of community formation in metal music. Through theoretical reflections on communal formation and empirical research in the ...field, the authors focus on how metal communities are conceptualized, created, shaped, maintained, interact with their context, and address internal tensions. Scholars interested in extreme music and community formation will become familiar with this particular collective experience, now prevalent throughout the world". The book critically examines the issue of community formation in metal music. Via theoretical reflections on communal formation and empirical research in the field, scholars interested in extreme music and community formation will become familiar with this particular collective experience, now prevalent throughout the world.
E-selectin and intercellular adhesion molecule (ICAM)-1 are crucial to the inflammatory response in chronic inflammatory arthritis. Soluble (s) levels of these molecules in sera and synovial fluid ...(SF) correlate with some clinical parameters and synovial tissue expression of the same molecules in rheumatoid arthritis. Studies of sera from children with chronic inflammatory arthritis corroborate this information; corresponding SF data are relatively lacking. We thus studied SF sE-selectin and sICAM-1 in 28 children with active juvenile rheumatoid arthritis or a spondyloarthropathy. Levels were correlated with erythrocyte sedimentation rate (ESR), SF leukocyte counts, duration of disease, and duration of response to concomitant intra-articular corticosteroid injection. Levels were compared according to use of methotrexate and/or sulfasalazine. Synovial fluid sE-selectin correlated with ESR and SF leukocyte counts. There was a trend toward lower sICAM-1 in patients treated with sulfasalazine and/or methotrexate. We conclude that SF levels of sE-selectin accurately reflect intra-synovial inflammation. Soluble ICAM-1 levels may reflect the effects of disease-modifying agents.
Dimensionality reduction techniques are powerful tools for data preprocessing and visualization which typically come with few guarantees concerning the topological correctness of an embedding. The ...interleaving distance between the persistent homology of Vietoris-Rips filtrations can be used to identify a scale at which topological features such as clusters or holes in an embedding and original data set are in correspondence. We show how optimization seeking to minimize the interleaving distance can be incorporated into dimensionality reduction algorithms, and explicitly demonstrate its use in finding an optimal linear projection. We demonstrate the utility of this framework to data visualization.
Towards nanotube linear servomotors Lixin Dong; Nelson, B.J.; Fukuda, T. ...
IEEE transactions on automation science and engineering,
07/2006, Letnik:
3, Številka:
3
Journal Article
Odprti dostop
Nanoscale linear servomotors with integrated position sensing are investigated from experimental, theoretical, and design perspectives. Prismatic motion is realized using the interlayer motion of ...telescoping multiwalled carbon nanotubes (MWNTs). Position sensing can be achieved by monitoring field emission or by measuring resistance change between an MWNT and a gold substrate during sliding movement. Experimental results demonstrate resolution in the nanometer range. Actuation experiments demonstrate the feasibility of a linear nanoservomotor with integrated position sensing based on field emission. A local "kink"-like fluctuation of emission current is observed, which is caused by the change of the protruding length of the nanotube core, thus demonstrating the potential of using emission as a "linear encoder." The complete extension of the inner core is observed and the electrostatic force is calibrated to be tens of nano-Newtons for individual nanotubes-16.5 nN under a 30-V bias. These results demonstrate the possibility of fabricating linear servomotors at the nanometer scale with integrated position sensing. Note to Practitioners-Nanometer scale actuators and sensors that can provide motion and measurement with nanometer-order resolution will enable new industrial applications in which only a few atoms or molecules are measured, transported, or processed. Linear servomotors will play a significant role in such applications because they provide precision prismatic motion directly without requiring a conversion from rotary to linear motion. Nano linear servomotors are experimentally and theoretically investigated in this paper. The devices take advantage of the ultra-low interlayer friction of a multiwalled carbon nanotube (MWNT). Position sensing feedback is achieved by monitoring field emission, which depends on interelectrode distance, or by measuring resistance change between an MWNT and a gold substrate during sliding movement. Whereas this paper targets long-term nanotechnology contributions, some intermediate results are ready for applications in the near future. The interlayer sliding motion demonstrated would enable the building of devices, such as Gigahertz oscillators and attolitter nanosyringes, and the sensors used for position feedback could find applications independently in a macro or microscale machine for detecting proximity, touch, displacement, or orientation.
Solution-processed Bii3 solar cells Hamdeh, Umar H.; Nelson, Rainie D.; Ryan, Bradley J. ...
2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC),
2016-June
Conference Proceeding
We present a proof-of-concept solid state solar cell with an efficiency of 1.0 % using solution-processed BÍI3 absorber layer. Spin-coated BiI3 thin films show stability in air for over one month. ...The films were integrated into an all-inorganic photovoltaic device with a transition-metal oxide hole transport layer. Thermal annealing BiL· films at 100 °C in a solvent vapor led to the highest short circuit current value of 6.9 ± 0.5 mA/cm 2 . In general, these devices have a large open circuit voltage deficit. EQE measurements show low collection efficiency at the BiI 3 -TiO 2 interface, indicating a potential pathway toward improved power conversion efficiencies.
Abstract
Phylogeographic inference has typically relied on analyses of data from one or a few genes to provide estimates of demography and population histories. While much has been learned from these ...studies, all phylogeographic analysis is conditioned on the data, and thus, inferences derived from data that represent a small sample of the genome are unavoidably tenuous. Here, we demonstrate one approach for moving beyond classic phylogeographic research. We use sequence capture probes and Illumina sequencing to generate data from >400 loci in order to infer the phylogeographic history of
Salix melanopsis
, a riparian willow with a disjunct distribution in coastal and the inland Pacific Northwest. We evaluate a priori phylogeographic hypotheses using coalescent models for parameter estimation, and the results support earlier findings that identified post‐Pleistocene dispersal as the cause of the disjunction in
S. melanopsis
. We also conduct a series of model selection exercises using
IM
a2, Migrate‐n and ∂a∂i. The resulting ranking of models indicates that refugial dynamics were complex, with multiple regions in the inland regions serving as the source for postglacial colonization. Our results demonstrate that new sources of data and new approaches to data analysis can rejuvenate phylogeographic research by allowing for the identification of complex models that enable researchers to both identify and estimate the most relevant parameters for a given system.
We report Au/Ru core–shell nanowire motors. These nanowires are fabricated using our previously developed electrodeposition-based technique, and their catalytic locomotion in the presence of H2O2 is ...investigated. Unlike conventional bimetallic nanowires that are self-electroosmotically propelled, our open-ended Au/Ru core–shell nanowires show both a noticeable decrease in rotational diffusivity and increase in motor speed with increasing nanowire length. Numerical modeling based on self-electroosmosis attributes decreases in rotational diffusivity to the formation of toroidal vortices at the nanowire tail, but fails to explain the speed increase with length. To reconcile this inconsistency, we propose a combined mechanism of self-diffusiophoresis and electroosmosis based on the oxygen gradient produced by catalytic shells. This mechanism successfully explains not only the speed increase of Au/Ru core–shell nanomotors with increasing length, but also the large variation in speed among Au/Ru, Au/Rh, and Rh/Au core–shell nanomotors. The possible contribution of diffusiophoresis to an otherwise well-established electroosmotic mechanism sheds light on future designs of nanomotors, at the same time highlighting the complex nature of nanoscale propulsion.
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