Smooth enucleation of bovine oocyte by microrobot with local flow speed control in microchannel

SUMMARY Scombrid fishes are known for high-performance locomotion; however, few data are available on scombrid locomotor hydrodynamics. In this paper, we present flow visualization data on patterns of water movement over the caudal peduncle and finlets (small fins on the dorsal and ventral body margin anterior to the caudal fin). Chub mackerel, Scomber japonicus, ranging in fork length from 20 to 26 cm, swam steadily at 1.2forklengthss−1 in a recirculating flow tank. Small, reflective particles in the flow tank were illuminated by a vertical (xy) or horizontal (xz) laser light sheet. Patterns of flow in the region near the caudal peduncle were measured using digital particle image velocimetry. Patterns of flow along the peduncle and finlets were quantified using manual particle tracking; more than 800 particles were tracked for at least 12ms over a series of tailbeats from each of four fish. In the vertical plane, flow trajectory and flow speed were independent of the position of the finlets, indicating that the finlets did not redirect flow or affect flow speed. Along, above and below the trailing surface of the peduncle, where the finlets were oriented along the peduncular surface, flow was convergent. Along, above and below the leading surface of the peduncle, where the finlets were absent, the flow trajectory was effectively horizontal. The lack of divergent flow on the leading surface of the peduncle is consistent with cross-peduncular flow formed by the lateral motion of the peduncle interacting with convergent flow resulting from forward movement of the body. In the horizontal plane, particles illuminated by the xz light sheet situated approximately 3 mm below the ventral body surface were tracked within the laser light sheet for up to 40ms, indicating strong planar flow. As the peduncle decelerates, the most posterior finlet is frequently at an angle of attack of at least 20° to the incident flow, but this orientation does not result in thrust production from lift generation. Finlet 5 does redirect cross-peduncular flow and probably generates small vortices undetectable in this study. These data are the first direct demonstration that the finlets have a hydrodynamic effect on local flow during steady swimming.

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Local flow sensing on helical microrobots for semi-automatic motion adaptation

The International Journal of Robotics Research ◽

10.1177/0278364919894374 ◽

2019 ◽

Vol 39 (4) ◽

pp. 476-489 ◽

Cited By ~ 4

Author(s):

Antoine Barbot ◽

Dominique Decanini ◽

Gilgueng Hwang

Keyword(s):

Closed Loop ◽

Flow Speed ◽

Closed Loop Control ◽

Flow Profile ◽

Microfluidic Chips ◽

Level Control ◽

Local Flow ◽

Loop Control ◽

Flow Sensing ◽

Swimming Motion

Helical microrobots with dimensions below 100 µm could serve many applications for manipulation and sensing in small, closed environments such as blood vessels or inside microfluidic chips. However, environmental conditions such as surface stiction from the channel wall or local flow can quickly result in the loss of control of the microrobot, especially for untrained users. Therefore, to automatically adapt to changing conditions, we propose an algorithm that switches between a surface-based motion of the microrobot and a 3D swimming motion depending on the local flow value. Indeed swimming is better for avoiding obstacles and difficult surface stiction areas but it is more sensitive to the flow than surface motion such as rolling or spintop motion. First, we prove the flow sensing ability of helical microrobots based on the difference between the tracked and theoretical speed. For this, a 50 µm long and 5 µm diameter helical microrobot measures the flow profile shape in two different microchannels. These measurements are then compared with simulation results. Then, we demonstrate both swimming and surface-based motion using closed-loop control. Finally, we test our algorithm by following a 2D path using closed-loop control, and adapting the type of motion depending on the flow speed measured by the microrobot. Such results could enable simple high-level control that could expand the development of microrobots toward applications in complex microfluidic environments.

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Continuous enucleation of bovine oocyte by microrobot with local flow distribution control

2012 International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO) ◽

10.1109/3m-nano.2012.6472969 ◽

2012 ◽

Author(s):

Lin Feng ◽

Akihiko Ichikawa ◽

Fumihito Arai ◽

Masaya Hagiwara

Keyword(s):

Flow Distribution ◽

Bovine Oocyte ◽

Local Flow

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Re-Assessment Survey of Large Diameter Pipelines Using Compact Multi-Purpose Inline Inspection Tools

2004 International Pipeline Conference, Volumes 1, 2, and 3 ◽

10.1115/ipc2004-0698 ◽

2004 ◽

Author(s):

Mikhail Viktorovich Bekker ◽

Thomas Beuker ◽

Uwe Thuenemann ◽

Steffen Paeper

Keyword(s):

Economic Impact ◽

Large Diameter ◽

Small Diameter ◽

Speed Control ◽

Flow Speed ◽

Operating Conditions ◽

Internal Space ◽

Pipeline Systems ◽

Elevation Changes ◽

Assessment Survey

Large diameter pipelines of 48” and 56” traverse the Ukraine. These pipelines are the life-line for the Russian gas transit to high demand European Union (EU) markets. The high economic impact to several European regions and the complicated legislation of these pipeline systems reduces the operators’ ability to change operating conditions to better suit in-line inspection. Ukrtransgaz requested a reliable and compact inspection tool able to negotiate 1.5D bends. Thirty degree (30°) mitre bends and demanding elevation changes in the range of 1500m (4921ft) also had to be considered. The high economic impact of the pipeline systems did not allow Ukrtransgaz to reduce the high flow speed of the gas, which is more than 10 m/s (22.2mph), during the inspection. In combination with the before-mentioned elevation profile, an inspection tool with active speed control was required. As part of the planned re-assessment survey, an XYZ mapping inspection relying on an inertial navigation system was also required. The inspection solutions provided by ROSEN were multipurpose tools providing MFL technology, an XYZ mapping module and active speed control in a single body. It will be discussed in this paper how the miniaturization of electronics and computer technology is not only a key point for small diameter tools, but also essential to meet the demanding targets of inspecting large diameter gas lines. Breaking with the paradigm, that large pipe provides enough internal space, was the basis in accomplishing the demands of the operator.

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Measurement of Intake Valve/Cylinder Boundary Flows Using a Multiple Orientation Hot-Wire Technique

Journal of Fluids Engineering ◽

10.1115/1.3243564 ◽

1988 ◽

Vol 110 (4) ◽

pp. 361-366 ◽

Cited By ~ 4

Author(s):

T. C. Wagner ◽

J. C. Kent

Keyword(s):

Flow Direction ◽

Sequential Sampling ◽

Effective Area ◽

Flow Speed ◽

Intake Valve ◽

Hot Wire ◽

Mean Velocity ◽

Local Flow ◽

Discharge Coefficients ◽

Velocity Magnitude

A new measurement method is utilized to determine velocity distributions on the intake-valve/cylinder boundary for different induction system designs. The velocity information is being used to calculate the angular momentum flux and to define local discharge coefficients around the valve periphery. The contribution of local flow direction (effective area) and local flow speed (velocity losses) to the global discharge coefficients is examined. The dependence of the discharge coefficient on the flow direction and mean velocity magnitude provides useful diagnostic data to relate intake port geometry and flow performance. The measurement technique is also described in detail. The directional response of a single hot-wire anemometer is utilized along with sequential sampling of the signal as the probe shaft is rotated through 360 deg. Within the range of velocity and flow direction required, the velocity magnitude and direction can be determined to within 2 percent and 2 deg, respectively.

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Transitional and Turbulent Flow Modeling in a Tesla Valve

Volume 7B: Fluids Engineering Systems and Technologies ◽

10.1115/imece2013-65526 ◽

2013 ◽

Cited By ~ 2

Author(s):

Scott M. Thompson ◽

Tausif Jamal ◽

Basil J. Paudel ◽

D. Keith Walters

Keyword(s):

Experimental Data ◽

Three Dimensional ◽

Reynolds Numbers ◽

Flow Speed ◽

Flow Modeling ◽

Ansys Fluent ◽

Local Flow ◽

Turbulent Characteristics ◽

Minor Losses ◽

Tesla Valve

A Tesla valve is a fluidic dioide that may be used in a variety of mini/micro channel applications for passive flow rectification and/or control. The valve’s effectiveness is quantified by the diodicity, which is primarily governed by the incoming flow speed, its design and direction-dependent minor losses throughout its structure during forward and reverse flows. It has been previously shown that the Reynolds number at the valve inlet is not representative of the entire flow regime throughout the Tesla structure. Therefore, pure-laminar solving methods are not necessarily accurate. Local flow instabilities exist and exhibit both transitional and turbulent characteristics. Therefore, the current investigation seeks to identify a suitable RANS-based flow modeling approach to predict Tesla valve diodicity via three-dimensional (3D) computational fluid dynamics (CFD) for inlet Reynolds numbers up to Re = 2,000. Using ANSYS FLUENT (v. 14), a variety of models were employed, including: the Realizable k-ε, k-kL-ω and SST k-ω models. All numerical simulations were validated against available experimental data obtained from an identically-shaped Tesla valve structure. It was found that the k-ε model drastically under-predicts experimental data for the entire range of Reynolds numbers investigated and cannot accurately model the Tesla valve flow. The k-kL-ω and SST k-ω models approach the experimentally-measured diodicity better than regular 2D CFD. The k-kL-ω demonstrates exceptional agreement with experimental data for Reynolds numbers up to approximately 1,500. However, both the k-kL-ω and k-ω SST models over-predict experimental data for Re = 2,000.

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Prediction of maximal expiratory flow in excised human lungs

Journal of Applied Physiology ◽

10.1152/jappl.1980.48.6.991 ◽

1980 ◽

Vol 48 (6) ◽

pp. 991-998 ◽

Cited By ~ 31

Author(s):

R. E. Hyatt ◽

T. A. Wilson ◽

E. Bar-Yishay

Keyword(s):

Pressure Drop ◽

Wave Speed ◽

Flow Speed ◽

Flow Limitation ◽

Frictional Loss ◽

Local Flow ◽

Lung Volumes ◽

Maximal Expiratory Flow ◽

Human Lungs ◽

Expiratory Flow

The predictions of the wave-speed theory of flow limitations were tested against measured values of maximal expiratory flow (Vmax) in nine normal excised human lungs. We obtained static pressure-volume curves and deflation pressure-area (PA) curves of the first three to four airway generations. The pressure drop from the alveolus to the flow-limitation site was assumed to consist of a peripheral frictional loss (estimated from a catheter upstream from the flow-limitation site) and a convective acceleration pressure drop. Predicted Vmax was determined graphically by finding the lowest flow for which the Bernoulli PA curve was tangent to one of the bronchial PA curves. At the point of tangency, local flow speed equals local wave speed. At low lung volumes a point of tangency with the PA curves of the first few generations did not exist, and the flow-limitation site was assumed to be the minimal bronchial area at zero transpulmonary pressure. There was good agreement between measured and predicted Vmax. Measured Vmax was not different from Vmax predicted from normal living man. The wave-speed theory predicted flow over much of the vital capacity, but other mechanisms may limit flow at low lung volumes.

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On-Chip Enucleation of Bovine Oocytes using Microrobot-Assisted Flow-Speed Control

Micromachines ◽

10.3390/mi4020272 ◽

2013 ◽

Vol 4 (2) ◽

pp. 272-285 ◽

Cited By ~ 22

Author(s):

Lin Feng ◽

Masaya Hagiwara ◽

Akihiko Ichikawa ◽

Fumihito Arai

Keyword(s):

Speed Control ◽

Flow Speed ◽

On Chip ◽

Bovine Oocytes

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Ertel Potential Vorticity versus Bernoulli Potential on Approximately Neutral Surfaces in the Antarctic Circumpolar Current

Journal of Physical Oceanography ◽

10.1175/jpo-d-19-0140.1 ◽

2020 ◽

Vol 50 (9) ◽

pp. 2621-2648

Author(s):

Geoffrey J. Stanley ◽

Timothy E. Dowling ◽

Mary E. Bradley ◽

David P. Marshall

Keyword(s):

Southern Ocean ◽

Potential Vorticity ◽

Antarctic Circumpolar Current ◽

Flow Speed ◽

Shear Instability ◽

Small Scale ◽

Local Flow ◽

Near Surface ◽

Circumpolar Current ◽

The Antarctic

AbstractWe investigate the relationship between Ertel potential vorticity Q and Bernoulli potential B on orthobaric density surfaces in the Antarctic Circumpolar Current (ACC), using the Southern Ocean State Estimate. Similar to the extratropical atmospheres of Earth and Mars, Q and B correlate in the ACC in a function-like manner with modest scatter. Below the near-surface, the underlying function relating Q and B appears to be nearly linear. Nondimensionalizing its slope yields “Ma,” a “Mach” number for long Rossby waves, the ratio of the local flow speed to the intrinsic long Rossby wave speed. We empirically estimate the latter using established and novel techniques that yield qualitatively consistent results. Previous work related “Ma” to the degree of homogeneity of Q and to Arnol’d’s shear stability criteria. Estimates of “Ma” for the whole ACC are notably positive, implying inhomogeneous Q, on all circumpolar buoyancy surfaces studied. Upper layers generally exhibit “Ma” slightly less than unity, suggesting that shear instability may operate within these layers. Deep layers exhibit “Ma” greater than unity, implying stability. On surfaces shallower than 1000 m just north of the ACC, the Q versus B slope varies strongly on subannual and interannual time scales, but “Ma” hovers near unity. We also study spatial variability: the ACC is speckled with hundreds of small-scale features with “Ma” near unity, whereas away from the ACC “Ma” is more commonly negative or above unity, both corresponding to stability. Maps of the time-mean “Ma” show stable regions occupy most of the Southern Ocean, except for several topographically controlled hotspots where “Ma” is always near unity.

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