Fluidic Surface-Tension-Directed Self-Assembly of Miniaturized Semiconductor Dies Across Length Scales and 3D Topologies

2009 ◽  
Vol 1179 ◽  
Author(s):  
Heiko Jacobs ◽  
Robert J Knuesel
Keyword(s):  
Surface Tension ◽  
Self Assembly ◽  
Recent Progress ◽  
Semiconductor Device ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Length Scales ◽  
Light Emitting ◽  
Dipping Process ◽  
3D Surfaces

AbstractThis proceeding discusses recent progress on engineered fluidic surface-tension-directed self-assembly involving liquid solder. The process is applied to the assembly of discrete inorganic semiconductor device components at different length scales producing electrically interconnected devices and systems. Prior results include assembly with unique angular orientation and contact pad registration, parallel packaging, and the programmable assembly of various types of light emitting diodes. Recent progress on the scaling of the minimal die size from 300 to 30 μm is discussed which required the development of a new delivery system to concentrate and effectively introduce the components to solder-based receptors. Specifically, components are pre-oriented at a liquid-air or liquid-liquid interface and transferred onto the solder based receptors using a dynamic contact angle with a dipping process. Recent applications include the tiling of curved and 3D surfaces with single crystal semiconductors including the formation of flexible 3D solar cells.

Spreading-Droplet Simulation With Surface Tension Model Using Inter-Particle Force in Particle Method

2013 ◽  
Author(s):  
Eiji Ishii ◽  
Taisuke Sugii
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Dynamic Contact Angle ◽  
Particle Method ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Particle Methods ◽  
Static Contact ◽  
Particle Force ◽  
Surface Tension Model

Predicting the spreading behavior of droplets on a wall is important for designing micro/nano devices used for reagent dispensation in micro-electro-mechanical systems, printing processes of ink-jet printers, and condensation of droplets on a wall during spray forming in atomizers. Particle methods are useful for simulating the behavior of many droplets generated by micro/nano devices in practical computational time; the motion of each droplet is simulated using a group of particles, and no particles are assigned in the gas region if interactions between the droplets and gas are weak. Furthermore, liquid-gas interfaces obtained from the particle method remain sharp by using the Lagrangian description. However, conventional surface tension models used in the particle methods are used for predicting the static contact angle at a three-phase interface, not for predicting the dynamic contact angle. The dynamic contact angle defines the shape of a spreading droplet on a wall. We previously developed a surface tension model using inter-particle force in the particle method; the static contact angle of droplets on the wall was verified at various contact angles, and the heights of droplets agreed well with those obtained theoretically. In this study, we applied our surface tension model to the simulation of a spreading droplet on a wall. The simulated dynamic contact angles for some Weber numbers were compared with those measured by Šikalo et al, and they agreed well. Our surface tension model was useful for simulating droplet motion under static and dynamic conditions.

Surface Tension and Dynamic Contact Angle of Water in Thin Quartz Capillaries

2000 ◽  
Vol 222 (1) ◽  
pp. 51-54 ◽  
Author(s):  
V.D. Sobolev ◽  
N.V. Churaev ◽  
M.G. Velarde ◽  
Z.M. Zorin
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Dynamic Contact Angle ◽  
Dynamic Contact

scholarly journals Surface Tension Directed Fluidic Self-Assembly of Semiconductor Chips across Length Scales and Material Boundaries

Micromachines ◽  
2016 ◽  
Vol 7 (4) ◽  
pp. 54 ◽  
Author(s):  
Shantonu Biswas ◽  
Mahsa Mozafari ◽  
Thomas Stauden ◽  
Heiko Jacobs
Keyword(s):  
Surface Tension ◽  
Self Assembly ◽  
Length Scales ◽  
Semiconductor Chips

Level Set Based Modeling of Electrowetting on Dielectrics Droplet

2012 ◽  
Vol 461 ◽  
pp. 138-141
Author(s):  
Yin Xia Chang ◽  
Si Xiang Zhang ◽  
Wei Zhou ◽  
Bao Liu
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Level Set ◽  
Stokes Equations ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Navier Stokes ◽  
Electric Force ◽  
Electrowetting On Dielectric ◽  
Static Contact

This paper discusses the modeling of Electrowetting On Dielectric (EWOD) device that moves fluid droplets through surface tension effects and electric force. Instead of using a static contact angle as most papers did, we take the dynamic contact angle into count by using expression proposed by Voinov and Tanner. Firstly, the level set model and its initial values is present. Then the governing equations are discussed, and the diffused format is adopted for density and viscosity varies to smooth over the interface. The detailed expression for surface tension and electric force are also described for Navier–Stokes equations. After presenting the boundary conditions, the steps of numerical implementation are detailed.

A Generalized Model for Dynamic Contact Angle

2017 ◽  
Author(s):  
Joseph J. Thalakkottor ◽  
Kamran Mohseni
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Contact Angle Hysteresis ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Force Balance ◽  
Surface Tension Gradient ◽  
Static Case ◽  
Dynamic Case ◽  
Microscopic Dynamic

Contact angle is an important parameter that characterizes the degree of wetting of a material. While for a static case, estimation and measurement of contact angle has been well established, same can not be said for the dynamic case. There is still a lack of understanding and consensus as to the fundamental factors governing the microscopic dynamic contact angle. With the aim of understanding the physics and identifying the parameters that govern the actual or microscopic dynamic contact angle, we derive a model based on first principles, by performing a force balance around the region containing the contact line. It is found that in addition to the surface tension, the microscopic dynamic contact angle is also a function of surface tension gradient and the jump in normal stress across the interface. In addition to having a significant contribution in determining the microscopic dynamic contact angle, surface tension gradient is also a key cause for contact angle hysteresis.

Measurements of the Contact Angles for Various Fluids Which Are Widely Used in the Oilfields to Improve Oil Recovery

2018 ◽  
Author(s):  
M. Elsharafi ◽  
K. Vidal ◽  
R. Thomas
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Interfacial Tension ◽  
Oil Recovery ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Rock Face ◽  
Angle Measurements ◽  
Contact Angle Measurements

Contact angle measurements are important to determine surface and interfacial tension between solids and fluids. A ‘water-wet’ condition on the rock face is necessary in order to extract oil. In this research, the objectives are to determine the wettability (water-wet or oil-wet), analyze how different brine concentrations will affect the wettability, and study the effect of the temperature on the dynamic contact angle measurements. This will be carried out by using the Cahn Dynamic Contact Angle. Analyzer DCA 315 to measure the contact angle between different fluids such as surfactant, alkaline, and mineral oil. This instrument is also used to measure the surface properties such as surface tension, contact angle, and interfacial tension of solid and liquid samples by using the Wilhelmy technique. The work used different surfactant and oil mixed with different alkaline concentrations. Varying alkaline concentrations from 20ml to 1ml were used, whilst keeping the surfactant concentration constant at 50ml.. It was observed that contact angle measurements and surface tension increase with increased alkaline concentrations. Therefore, we can deduce that they are directly proportional. We noticed that changing certain values on the software affected our results. It was found that after calculating the density and inputting it into the CAHN software, more accurate readings for the surface tension were obtained. We anticipate that the surfactant and alkaline can change the surface tension of the solid surface. In our research, surfactant is desirable as it maintains a high surface tension even when alkaline percentage is increased.

Moving contact lines in liquid/liquid/solid systems

1997 ◽  
Vol 334 ◽  
pp. 211-249 ◽  
Author(s):  
YULII D. SHIKHMURZAEV
Keyword(s):  
Mathematical Model ◽  
Surface Tension ◽  
Contact Angle ◽  
Flow Field ◽  
Contact Line ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Moving Contact Line ◽  
Moving Contact ◽  
Three Phase

A general mathematical model which describes the motion of an interface between immiscible viscous fluids along a smooth homogeneous solid surface is examined in the case of small capillary and Reynolds numbers. The model stems from a conclusion that the Young equation, σ1 cos θ = σ2 − σ3, which expresses the balance of tangential projection of the forces acting on the three-phase contact line in terms of the surface tensions σi and the contact angle θ, together with the well-established experimental fact that the dynamic contact angle deviates from the static one, imply that the surface tensions of contacting interfaces in the immediate vicinity of the contact line deviate from their equilibrium values when the contact line is moving. The same conclusion also follows from the experimentally observed kinematics of the flow, which indicates that liquid particles belonging to interfaces traverse the three-phase interaction zone (i.e. the ‘contact line’) in a finite time and become elements of another interface – hence their surface properties have to relax to new equilibrium values giving rise to the surface tension gradients in the neighbourhood of the moving contact line. The kinematic picture of the flow also suggests that the contact-line motion is only a particular case of a more general phenomenon – the process of interface formation or disappearance – and the corresponding mathematical model should be derived from first principles for this general process and then applied to wetting as well as to other relevant flows. In the present paper, the simplest theory which uses this approach is formulated and applied to the moving contact-line problem. The model describes the true kinematics of the flow so that it allows for the ‘splitting’ of the free surface at the contact line, the appearance of the surface tension gradients near the contact line and their influence upon the contact angle and the flow field. An analytical expression for the dependence of the dynamic contact angle on the contact-line speed and parameters characterizing properties of contacting media is derived and examined. The role of a ‘thin’ microscopic residual film formed by adsorbed molecules of the receding fluid is considered. The flow field in the vicinity of the contact line is analysed. The results are compared with experimental data obtained for different fluid/liquid/solid systems.

Recent developments in the construction of metallacycle/metallacage-cored supramolecular polymers via hierarchical self-assembly

2019 ◽  
Vol 55 (56) ◽  
pp. 8036-8059 ◽  
Author(s):  
Bo Li ◽  
Tian He ◽  
Yiqi Fan ◽  
Xinchao Yuan ◽  
Huayu Qiu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Recent Progress ◽  
Supramolecular Polymers ◽  
Feature Article ◽  
Light Emitting ◽  
Recent Developments ◽  
Potential Applications ◽  
Bio Imaging

This feature article summarized the recent progress on the construction of metallacycle/metallacage-cored supramolecular polymers by the hierarchical self-assembly, and the potential applications in the areas of light emitting, sensing, bio-imaging, delivery and release, etc., are also presented.

Rheological and Interfacial Property of Nano-Al with HTPB, GAP and PET

2014 ◽  
Vol 924 ◽  
pp. 170-175 ◽  
Author(s):  
Hui Xiang Xu ◽  
Wen Jing Zhou ◽  
Feng Qi Zhao ◽  
Wei Qiang Pang ◽  
Zhi Hua Sun ◽  
...  
Keyword(s):  
Activation Energy ◽  
Surface Tension ◽  
Contact Angle ◽  
Apparent Viscosity ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Interfacial Property ◽  
Flow Activation Energy ◽  
Flow Activation

Rheological and interfacial property of nanoAl with Hydroxyl-terminated polybutadiene (HTPB), glycidyl azide polymer (GAP) and poly (ethyleneoxide-co-tetrafuran)(PET) were investigated by means of RS-300 rheometer, DCAT21 dynamic contact angle measuring instrument, interface surface tension meter (Germany) and X-ray photoelectron spectroscopy (xps). Rheological properties of three binders and nanoAl/binder suspensions in the mixing ratio of 1:2 were discussed. Results show that Three kinds of binders exhibit pseudoplastic characteristics with the apparent viscosity of less than 3 Pa s,and have weak interaction between molecular chain segment of itself. Within 30~60°C, with temperature increasing, the apparent viscosity of nanoAl suspensions decreases, in which the nanoAl/HTPB and nanoAl/GAP belong to pseudoplastic fluid of sensitive to temperature, with flow activation energy of 38.05 kJ/mol and 52.07 kJ /mol, respectively, but nanoAl/PET belongs to a bingham fluid of sensitive to changes in the shear rate, with flow activation energy of only 1.506 kJ/mol. The contact angles of nanoAl,GAP,HTPB and PET were measured by means of dynamic contact angle/surface tension instrument. The calculated values of adhesion and spread coefficient of nanoAl with binders decrease in the order Wnano-Al/PET>Wnano-Al/GAP>Wnano-Al/HTPB and Snano-Al/PET>Snano-Al/GAP>Snano-Al/HTPB.The results indicate that the interactions of nanoAl with binders decrease in the order nanoAl/PET>nanoAl/GAP>nanoAl/HTPB,which is consistent with the trends of apparent viscosity of the suspensions . Binding energy of Oxygen in nanoAl/HTPB is 532.03 ev,which is bigger than that of nanoAl,and indicate a strong action between nanoAl and HTPB.

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