Untethered MicroRobot Motion Mechanism with Increased Longitudinal Force

2021 ◽  
pp. 1-12
Author(s):  
Ali Anil Demircali ◽  
Rahmetullah Varol ◽  
Kadir Erkan ◽  
Huseyin Uvet
Keyword(s):  
Flow Rate ◽  
Permanent Magnets ◽  
Pyrolytic Graphite ◽  
Longitudinal Force ◽  
High Flow ◽  
Experimental Results ◽  
Microfluidic Channels ◽  
Simulation Studies ◽  
Field Lines

Abstract The importance of an untethered microrobotic platform that can operate on high flow rate microfluidic channels for in-vitro applications is increasing rapidly. This paper presents a method to manipulate a microrobot in a fluidic chip when high flow rates (4 mL/min, 82.304 mm/s) are applied. This method is based on a novel permanent magnet-based diamagnetic levitation configuration. This configuration includes a thin layer of pyrolytic graphite, which is placed just below the microrobot. In this way, microrobot stability and manipulation capability are increased. Also, we aim to increase the longitudinal forces imposed on the microrobot to withstand the drag force proportional to the flow rate. Hence, magnetic field lines are generated more linearly around the microrobot by a different combination of permanent magnets. The proposed magnetic configuration, named “Kerkan configuration,” significantly improves the microrobot's longitudinal forces. In this configuration, two different ring-shaped ferromagnetic magnets are used. One of the magnets has a smaller diameter than the other magnet. A combination of one smaller and one bigger magnet is placed above and below the microrobot. In order to validate the advantages of this configuration, analytical and simulation studies are conducted. Their results are then compared with experimental results. Experimental results are on par with analytical and simulation studies. Kerkan configuration has a lower displacement than the next best configuration at the highest flow rate we applied (relatively 3301 µm, %21.8).

scholarly journals Influence of flow rate, fluid temperature, and extension line on Hotline and S-line heating capability: an in vitro study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hosu Kim ◽  
Tae Kyong Kim ◽  
Sukha Yoo ◽  
Jin-Tae Kim
Keyword(s):  
Flow Rate ◽  
Room Temperature ◽  
In Vitro Study ◽  
High Flow ◽  
High Flow Rate ◽  
Low Flow ◽  
Fluid Temperature ◽  
Flow Rates ◽  
Fluid Warmer

Abstract Background A fluid warmer can prevent hypothermia during the perioperative period. This study evaluated the heating capabilities of Hotline and Barkey S-line under different flow rates and initial fluid temperatures, as well as after the extension line installation. Methods We measured the temperature of a 0.9% sodium chloride solution at the fluid warmer outlet (TProx) and the extension line end (TDistal) with three different initial fluid temperatures (room, warm, and cold) and two flow rates (250 ml/hr and 100 mL/hr). Results At a 250 ml/hr flow rate, the TProx and TDistal values were observed to be higher in Hotline than in S-line when using room-temperature or cold fluid. Administering of the warm fluid at the same flow rate significantly increased the TProx and TDistal values in S-line more than the cold and room-temperature fluids. At flow rates of 100 ml/hr, TDistal values were significantly lower than TProx values in both devices regardless of the initial fluid temperature. Conclusions Hotline outperformed S-line for warming fluids at a high flow rate with cold or room-temperature fluids. Administering warm fluid in S-line prevented a decrease in the fluid temperature at a high flow rate. However, at a low flow rate, the fluid temperature significantly decreased in both devices after passing through an extension line.

Experiment Study of High-Temperature and High-Flow Rate Naphthenic Acid Corrosion

2011 ◽  
Author(s):  
Ke Jiang ◽  
Xuedong Chen ◽  
Tiecheng Yang ◽  
Zongchuan Qin
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Corrosion Rate ◽  
Flow Rate ◽  
Acid Corrosion ◽  
Naphthenic Acid ◽  
High Flow ◽  
High Flow Rate ◽  
Experimental Results ◽  
Wall Turbulence

The corrosion behaviors of 321 and 316L austenitic stainless steel in high-temperature and high-flow rate naphthenic acid medium were investigated by pipe-flow and jet-impingement method. The influence of temperature and erosion angle on naphthenic acid corrosion resistance for stainless steel was analyzed. The results indicate that the naphthenic acid corrosion rate increased with increasing temperature and velocity. At the same temperature, the corrosion rate at 90° erosion angle is greater than that at 0°. The present experimental results are very close to those in API 581. Simulation results indicate that, where the mutation of flow direction occurs around the specimen, the near-wall turbulence intensities are very large by both experimental methods. Moreover, by comparing both the simulation and experimental results, it can be found that the naphthenic acid corrosion is very severe in areas of high turbulence.

scholarly journals Influence of flow rate, fluid temperature, and extension line on Hotline and S-line heating capability: an in vitro study

2020 ◽  
Author(s):  
Hosu Kim ◽  
Tae Kyong Kim ◽  
Sukha Yoo ◽  
Jin-Tae Kim
Keyword(s):  
Flow Rate ◽  
Room Temperature ◽  
In Vitro Study ◽  
High Flow ◽  
High Flow Rate ◽  
Low Flow ◽  
Fluid Temperature ◽  
Flow Rates ◽  
Fluid Warmer

Abstract Background A fluid warmer can prevent hypothermia during the perioperative period. This study evaluated the heating capabilities of Hotline and Barkey S-line under different flow rates and initial fluid temperatures, as well as after the extension line installation. Methods We measured the temperature of a 0.9% sodium chloride solution at the fluid warmer outlet (TProx) and the extension line end (TDistal) with three different initial fluid temperatures (room, warm, and cold) and two flow rates (250 ml/hr and 100 mL/hr). Results At a 250 ml/hr flow rate, the TProx and TDistal values were observed to be higher in Hotline than in S-line when using room-temperature or cold fluid. Administering of the warm fluid at the same flow rate significantly increased the TProx and TDistal values in S-line more than the cold and room-temperature fluids. At flow rates of 100 ml/hr, TDistal values were significantly lower than TProx values in both devices regardless of the initial fluid temperature. Conclusions Hotline outperformed S-line for warming fluids at a high flow rate with cold or room-temperature fluids. Administering warm fluid in S-line prevented a decrease in the fluid temperature at a high flow rate. However, at a low flow rate, the fluid temperature significantly decreased in both devices after passing through an extension line.

Continuous in vivo measurement of arterial PO2 in humans

1975 ◽  
Vol 38 (4) ◽  
pp. 730-735 ◽  
Author(s):  
K. Jank ◽  
J. de Hemptinne ◽  
A. Swietochowski ◽  
M. Demeester
Keyword(s):  
Flow Rate ◽  
Electrode Surface ◽  
Blood Velocity ◽  
High Flow ◽  
Fixed Position ◽  
In Vivo Measurement ◽  
Stable Variation ◽  
Arterial Po2

A system suitable for prolonged continuous in vivo measurement of human arterial PO2 is described. The system uses a polarographic electrode developed by Kimmich and Kreuzer, inserted in a specially made shunt between the radial artery and an antecubital vein. Nhe electrode surface is maintained in a fixed position parallel to the flow of blood; blood velocity dependency is small owing to the high flow rate achieved (more than 40 cm/s); clotting is prevented by the material used and the continuous instillation of heparin through the arterial end of the shunt. The system has been tested in vitro; it is stable (variation less than 0.5% in 24 h), linear and precise (plus or minus 0.2%) in a broad range of PO2 values (from about 10 mmHg to more than 700 mmHg); its response time is 0.4 s per 95% of deflection. It has been applied to 35 patients for periods ranging between 6 and 24 h; most of the patients were ventilated by an Engstrom respirator.

scholarly journals Influence of flow rate, fluid temperature, and extension line on Hotline and S-line heating capability: an in vitro study

2020 ◽  
Author(s):  
Hosu Kim ◽  
Tae Kyong Kim ◽  
Sukha Yoo ◽  
Jin-Tae Kim
Keyword(s):  
Flow Rate ◽  
Room Temperature ◽  
In Vitro Study ◽  
High Flow ◽  
High Flow Rate ◽  
Low Flow ◽  
Fluid Temperature ◽  
Flow Rates ◽  
Fluid Warmer

Abstract Background A fluid warmer can prevent hypothermia during the perioperative period. This study evaluated the heating capabilities of Hotline and Barkey S-line under different flow rates and initial fluid temperatures, as well as after the extension line installation. Methods We measured the temperature of a 0.9% sodium chloride solution at the fluid warmer outlet (TProx) and the extension line end (TDistal) with three different initial fluid temperatures (room, warm, and cold) and two flow rates (250 ml/hr and 100 mL/hr). Results At a 250 ml/hr flow rate, the TProx and TDistal values were observed to be higher in Hotline than in S-line when using room-temperature or cold fluid. Administering of the warm fluid at the same flow rate significantly increased the TProx and TDistal values in S-line more than the cold and room-temperature fluids. At flow rates of 100 ml/hr, TDistal values were significantly lower than TProx values in both devices regardless of the initial fluid temperature. Conclusions Hotline outperformed S-line for warming fluids at a high flow rate with cold or room-temperature fluids. Administering warm fluid in S-line prevented a decrease in the fluid temperature at a high flow rate. However, at a low flow rate, the fluid temperature significantly decreased in both devices after passing through an extension line.

Modeling and Experimental Study of Flow Forces for Unstable Valve Design

2003 ◽  
Author(s):  
Qinghui Yuan ◽  
Perry Y. Li
Keyword(s):  
Experimental Study ◽  
Flow Control ◽  
Steady Flow ◽  
Flow Rate ◽  
High Flow ◽  
High Flow Rate ◽  
Experimental Results ◽  
Valve Design ◽  
Electromagnetic Actuators ◽  
New Models

Single stage electrohydraulic flow control valves are currently not suitable in high flow rate and high frequency applicaitons. This is due to the very significant flow induced forces and the power/force limitation of electromagnetic actuators that directly stokes the spool. An unstable valve has been proposed that can utilize the flow forces to achieve fast responses at high flow rate. In this paper, we model the flow forces, including both steady and transient, of a directional flow control valve for incompressible and viscous fluid. In particular, the viscosity effect and non-orifice flux are investigated. The new models have been verified by CFD analysis to be more accurate than the old models. The paper also presents a systematic experimental study on the flow forces, in particular on the steady flow forces. The estimates according to our new models, revised slightly due to the limitation of the experiment, are consistent with the experimental results. Both the experimental results and the modeling estimation show that, for an unstable valve with negative damping length, both transient and steady flow forces can help to achieve the higher spool agility. The satisfactory modeling and experimental study on the flow forces give us a grounding for the future research of unstable valve design.

scholarly journals Influence of Flow Rate, Fluid Temperature, and Extension Line on Hotline and S-Line Heating Capability: an in Vitro Study

2020 ◽  
Author(s):  
Hosu Kim ◽  
Tae Kyong Kim ◽  
Sukha Yoo ◽  
Jin-Tae Kim
Keyword(s):  
Flow Rate ◽  
Room Temperature ◽  
In Vitro Study ◽  
High Flow ◽  
High Flow Rate ◽  
Low Flow ◽  
Fluid Temperature ◽  
Flow Rates ◽  
Fluid Warmer

Abstract Background A fluid warmer can prevent hypothermia during the perioperative period. This study evaluated the heating capabilities of Hotline and Barkey S-line under different flow rates and initial fluid temperatures, as well as after the extension line installation. Methods We measured the temperature of a 0.9% sodium chloride solution at the fluid warmer outlet (TProx) and the extension line end (TDistal) with three different initial fluid temperatures (room, warm, and cold) and two flow rates (250 ml/hr and 100 mL/hr). Results At a 250 ml/hr flow rate, the TProx and TDistal values were observed to be higher in Hotline than in S-line when using a room-temperature fluid; similar results were observed for the cold fluid. Administration of the warm fluid was observed to significantly increase the TProx and TDistal values in S-line at rates of 250 ml/hr more than the administration of the cold and room-temperature fluids. At flow rates of 100 ml/hr, TDistal values were significantly lower than TProx values in both devices regardless of the initial fluid temperature. Conclusions Hotline outperformed S-line for warming fluids at a high flow rate with cold or room-temperature fluids. The administration of the initially warm fluid prevented a decrease in the fluid temperature at a high flow rate in S-line. However, at a low flow rate, the fluid temperature significantly decreased in both devices after passing through an extension line.

Toxicological evaluation of MnAl based permanent magnets using different in vitro models

Chemosphere ◽  
2021 ◽  
Vol 263 ◽  
pp. 128343
Author(s):  
Carlos Rumbo ◽  
Cristina Cancho Espina ◽  
Vladimir V. Popov ◽  
Konstantin Skokov ◽  
Juan Antonio Tamayo-Ramos
Keyword(s):  
Permanent Magnets ◽  
In Vitro Models ◽  
Toxicological Evaluation
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