Capillary-Based Liquid Micro/Nano Deposition

2011 ◽  
Author(s):  
Artur Lutfurakhmanov ◽  
Yechun Wang ◽  
Douglas L. Schulz ◽  
Iskander S. Akhatov
Keyword(s):  
Liquid Bridge ◽  
Liquid Droplet ◽  
Applied Pressure ◽  
Deposition Process ◽  
Contact Angles ◽  
Liquid Pressure ◽  
Bridge Formation ◽  
Non Invasive ◽  
Two Parameters ◽  
Nano Imprint

Micro/Nanolithography is a creation of micro/nano features on the substrate. Several lithography techniques have been recently developed, including dip-pen nanolithography, nano-imprint lithography, electron-beam lithography, and photolithography. However, all these techniques possess some limitations because of a direct contact with the substrate. This paper proposes a new method that is non-invasive both to the substrate and to the writing tip. The method is based on hollow capillary filled with liquid to be deposited. The application of pressure from one side of capillary causes the liquid meniscus to form at the capillary outlet. Touching the substrate with the meniscus only leads to the liquid bridge formation between the capillary and the substrate. Withdrawing the capillary away from the substrate causes deposition of liquid droplet on the substrate. Theoretical modeling reveals two possible regimes of the liquid bridge formation: stable — “good” bridge and unstable — “bad” bridge. Liquid bridge stability map was created based on two parameters: liquid pressure and the capillary-substrate distance. It was found that the main parameter responsible for the deposition process is the applied pressure. Three pressure ranges were identified with different deposition scenarios. The influence of liquid-capillary and liquid-substrate equilibrium contact angles along with the capillary wall thickness on the liquid bridge stability is discussed.

scholarly journals Energy harvesting performance of an EDLC power generator based on pure water and glycerol mixture: analytical modeling and experimental validation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dong Kim ◽  
Dae Yeon Kim ◽  
Jaesool Shim ◽  
Kyung Chun Kim
Keyword(s):  
Energy Harvesting ◽  
Liquid Bridge ◽  
Liquid Droplet ◽  
Pure Water ◽  
Contact Angles ◽  
Phase Field Method ◽  
Peak Voltage ◽  
Glycerol Water ◽  
Electrowetting On Dielectric ◽  
Ito Glass

AbstractA liquid droplet oscillating between two plane electrodes was visualized, and the electrical power generation based on the reverse-electrowetting-on-dielectric (REWOD) phenomenon was measured. For the upper plate, a hydrophobic surface treated by PTFE was used, and the lower plate was tested using the hydrophilic surface properties of ITO glass. To analyze the dynamic behavior of an oscillating liquid bridge, a modeling study was carried out using the phase field method based on the finite element method. The dynamic contact angle of the oscillating liquid bridge was modeled based on advancing and receding contact angles. The variable interfacial areas between the liquid and solid surfaces were calculated and agreed well with the experimental results within a 10% error band. Furthermore, experimental and analytical studies were carried out to examine the REWOD energy harvesting characteristics of the glycerol-water mixtures in various concentrations. As a result, the peak voltage output was obtained at a specific concentration of the glycerol mixture, and the power density of the oscillating liquid bridge at this point was up to 2.23 times higher than that of pure water.

scholarly journals Sessile droplets on deformable substrates

2018 ◽  
Author(s):  
Gulraiz Ahmed ◽  
Nektaria Koursari ◽  
Anna Trybala ◽  
Victor M. Starov
Keyword(s):  
Liquid Droplet ◽  
Contact Angles ◽  
Surface Forces ◽  
Interfacial Behavior ◽  
Equilibrium Conditions ◽  
The Past ◽  
Technological Advances ◽  
Three Phase ◽  
Significant Interest ◽  
Receding Contact

Wetting of deformable substrates has gained significant interest over the past decade due to its extensive applications and uses. This interest has developed due to technological advances which are able to capture interfacial behavior taking place when a liquid droplet is placed on a deformable substrate. Researchers have developed different theories to explain processes taking place in the process of wetting of deformable/soft substrates. For the scope of this review, we will consider the fluid to be Newtonian, partially wetting, and surface forces are incorporated with the help of disjoining/conjoining pressure acting in the vicinity of the apparent, three-phase contact line. The following subjects are briefly reviewed: (i) Equilibrium of droplets on soft substrates. It is shown that properties of the disjoining/conjoining pressure isotherm and properties of the deformable substrate determine both the shape of the liquid droplet and deformation of the substrate; (ii) Equilibrium conditions of droplets on deformable substrates. It is shown that for a droplet to be at equilibrium on a deformable substrate under consideration, Jacobi’s sufficient condition is satisfied; (iii) Hysteresis of contact angle of sessile droplets on deformable substrates. It is shown that as the elasticity of the deformable substrate is increased, both advancing and receding contact angles are reduced.

scholarly journals Molecular Dynamics Simulation of Wetting Behavior: Contact Angle Dependency on Water Potential Models

2021 ◽  
Vol 1 (1) ◽  
pp. 10
Author(s):  
Lukman Hakim ◽  
Irsandi Dwi Oka Kurniawan ◽  
Ellya Indahyanti ◽  
Irwansyah Putra Pradana
Keyword(s):  
Molecular Dynamics ◽  
Contact Angle ◽  
Liquid Droplet ◽  
Center Of Mass ◽  
Contact Angles ◽  
Surface Wettability ◽  
Dynamics Simulation ◽  
Potential Models ◽  
Surface Hydrophilicity ◽  
Dynamics Simulations

The underlying principle of surface wettability has obtained great attentions for the development of novel functional surfaces. Molecular dynamics simulations has been widely utilized to obtain molecular-level details of surface wettability that is commonly quantified in term of contact angle of a liquid droplet on the surface. In this work, the sensitivity of contact angle calculation at various degrees of surface hydrophilicity to the adopted potential models of water: SPC/E, TIP4P, and TIP5P, is investigated. The simulation cell consists of a water droplet on a structureless surface whose hydrophilicity is modified by introducing a scaling factor to the water-surface interaction parameter. The simulation shows that the differences in contact angle described by the potential models are systematic and become more visible with the increase of the surface hydrophilicity. An alternative method to compute a contact angle based on the height of center-of-mass of the droplet is also evaluated, and the resulting contact angles are generally larger than those determined from the liquid-gas interfacial line.

Non-Invasive Monitoring of Hemodynamic Parameters during Hemodialysis

1995 ◽  
Vol 18 (9) ◽  
pp. 499-503 ◽  
Author(s):  
F. Pizzarelli ◽  
P. Dattolo ◽  
M. Piacenti ◽  
M.A. Morales ◽  
T. Cerrai ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Blood Volume ◽  
Impedance Cardiography ◽  
Hemodynamic Parameters ◽  
Non Invasive ◽  
Transthoracic Impedance ◽  
Cardiac Output Index ◽  
On Line ◽  
Two Parameters

We studied in 13 hemodialysis patients intradialytic variations of blood volume (BV) and cardiac output, by means of non-invasive methods. We found a weak correlation, r 0.2 or less, between BV variations and intradialysis blood pressure variations. The sensitivity of the former in describing the variations of the latter was only 32%. During the 30 min preceeding the hypotensive crisis the percent BV variations did not show any predictive trend. On the contrary, refilling increased as blood pressure dropped and a weak inverse relation (r -0.35) was found between these two parameters. Unstable patients had predialytic blood volume values significantly lower than stable ones and comparable to healthy subjects. On the contrary, the correlation between percent variations of cardiac output index and MAP was 0.68 with a sensitivity and specificity of 90% and 59%, respectively. Unfortunately these promising results were obtained only with an estimate of cardiac output obtained by echocardiography and not by transthoracic impedance cardiography, which is much more feasible than the former as on-line monitoring of cardiac output. On-line monitoring of hemodynamic parameters is an appealing but still unsolved task.

Bridge Dynamics for Capillary-Based Liquid Deposition

2012 ◽  
Author(s):  
Artur Lutfurakhmanov ◽  
Yechun Wang ◽  
Douglas L. Schulz
Keyword(s):  
Experimental Data ◽  
Contact Line ◽  
Liquid Droplet ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Non Invasive ◽  
Contact Line Motion ◽  
Liquid Deposition ◽  
Good Agreement ◽  
Bridge Dynamics

A new capillary-based lithography technique of liquid droplet deposition is further developed. Main advantage of this method in comparison with others techniques is that it is non-invasive both to the substrate and to the writing tip. The method is studied both theoretically and experimentally. To adequately describe bridge dynamics between the capillary and the substrate, proper boundary conditions must be set in the model for the liquid-surface interface. Based on literature review, two laws of contact line motion are identified: Tanner’s law and Blake’s equation. These two approaches are tested in multiple experiments with different retraction speeds from 3 microns/s to 300 microns/s. Analysis of the experimental data show that both Tanner’s and Blake’s equation can describe the correlation between the contact line velocity and the dynamic contact angle. In addition, both laws are employed in the direct numerical simulation of the bridge dynamics using 3D spectral boundary element method. Modeling results are compared with experimental data and show good agreement.

scholarly journals Detection of cirrhosis through ultrasound imaging by intensity difference technique

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Karan Aggarwal ◽  
Manjit Singh Bhamrah ◽  
Hardeep Singh Ryait
Keyword(s):  
High Performance ◽  
Research Work ◽  
Region Of Interest ◽  
Normal Liver ◽  
Cirrhotic Liver ◽  
Intensity Difference ◽  
Non Invasive ◽  
The Us ◽  
The Difference ◽  
Two Parameters

Abstract Cirrhosis is a liver disease that is considered to be among the most common diseases in healthcare. Due to its non-invasive nature, ultrasound (US) imaging is a widely accepted technology for the diagnosis of this disease. This research work proposed a method for discriminating the cirrhotic liver from normal liver through US images. The liver US images were obtained from the radiologist. The radiologist also specified the region of interest (ROI) from these images, and then the proposed method was applied to it. Two parameters were extracted from the US images through differences in intensity of neighboring pixels. Then, these parameters can be used to train a classifier by which cirrhotic region of test patient can be detected. A 2-D array was created by the difference in intensity of the neighboring pixels. From this array, two parameters were calculated. The decision was taken by checking these parameters. The validation of the proposed tool was done on 80 images of cirrhotic and 30 images of normal liver, and classification accuracy of 98.18% was achieved. The result was also verified by the radiologist. The results verified its possibility and applicability for high-performance cirrhotic liver discrimination.

Ring-Shaped Sessile Droplet

2011 ◽  
Author(s):  
Svyatoslav S. Chugunov ◽  
Douglas L. Schulz ◽  
Iskander S. Akhatov
Keyword(s):  
Contact Angle ◽  
Liquid Droplet ◽  
Liquid Structure ◽  
Solid Substrate ◽  
Contact Angles ◽  
Equilibrium Contact Angle ◽  
Sessile Droplet ◽  
System Equilibrium ◽  
Energy Consideration ◽  
External Forces

It is recognized that small liquid droplet placed on the solid substrate forms equilibrium contact angle that can be obtained from well-known Young’s law. Previously, deviations from Young’s law were demonstrated for the droplets exposed to external fields (gravity, electric, etc) and for the droplets on non-homogeneous substrates. This work reveals that the Young’s equilibrium contact angle can be altered by geometrical reasons only. We consider a ring-shaped droplet on a solid substrate as a test structure for our discussion. We use the global energy consideration for analysis of system equilibrium for the case of freely deposited liquid with no external forces applied. The theoretical analysis shows that steady ring-shaped liquid structure on a solid substrate does exist with contact angles on both contact lines to be different from the Young’s equilibrium contact angle.

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