scholarly journals Viscoelastic properties of suspended cells measured with shear flow deformation cytometry

2022 ◽  
Author(s):  
Richard Carl Gerum ◽  
Elham Mirzahossein ◽  
Mar Eroles ◽  
Jennifer Elsterer ◽  
Astrid Mainka ◽  
...  
Keyword(s):  
Viscoelastic Properties ◽  
Fluid Shear Stress ◽  
Loss Modulus ◽  
Low Cost ◽  
Microfluidic Channel ◽  
High Viscosity ◽  
Flow Profile ◽  
Cell Functions ◽  
Viscous Loss ◽  
Suspended Cells

Numerous cell functions are accompanied by phenotypic changes in viscoelastic properties, and measuring them can help elucidate higher-level cellular functions in health and disease. We present a high-throughput, simple and low-cost microfluidic method for quantitatively measuring the elastic (storage) and viscous (loss) modulus of individual cells. Cells are suspended in a high-viscosity fluid and are pumped with high pressure through a 5.8 cm long and 200 μm wide microfluidic channel. The fluid shear stress induces large, near ellipsoidal cell deformations. In addition, the flow profile in the channel causes the cells to rotate in a tank-treading manner. From the cell deformation and tank treading frequency, we extract the frequency-dependent viscoelastic cell properties based on a theoretical framework developed by R. Roscoe that describes the deformation of a viscoelastic sphere in a viscous fluid under steady laminar flow. We confirm the accuracy of the method using atomic force microscopy-calibrated polyacrylamide beads and cells. Our measurements demonstrate that suspended cells exhibit power-law, soft glassy rheological behavior that is cell cycle-dependent and mediated by the physical interplay between the actin filament and intermediate filament networks.

Dynamic and Static Sagging Characterization and Performances of Four Oil Based Muds

2016 ◽  
Author(s):  
Mesfin Belayneh ◽  
Bernt S. Aadnøy ◽  
Sharman Thomas
Keyword(s):  
Yield Stress ◽  
Storage Modulus ◽  
Viscoelastic Properties ◽  
Loss Modulus ◽  
Drilling Fluid ◽  
High Viscosity ◽  
Experimental Result ◽  
Drilling Fluids ◽  
Oil Water ◽  
Water Ratio

This paper presents the barite sagging phenomenon of four OBM systems having the same density, but different rheology properties. The investigations of barite sagging is based on dynamic sagging and viscoelasticity testing. The viscoelastic properties related to gel formation of the drilling fluids were investigated under amplitude and frequency sweeps. The study also tries to correlate the results obtained from dynamic sag with the dynamic viscoelastic properties of the drilling fluid and standard API rheology parameters. The results show that as the oil water ratio increases the drilling fluid rheology parameters such as lower shear yield stress (LSYS), yield stress (YS) and plastic viscosity (PV) parameters also increases. In addition, the viscoelastic loss and storage modulus decrease. From the viscoelasticity study, except for 90:10 OWR, it is observed that as the oil water ratio increase, the yield stress and the flow point also increases. The 90:10 OBM shows no viscoelasticity behavior. Comparing the extreme 60:40 and 90:10 OBMs (i.e. as OWR increase), the experimental result shows that the sagging index increases by 9%. The dynamic sagging factor decreases as the ratio of storage modulus to loss modulus increases (i.e. as OWR decrease). Except for high viscosity and hydraulics, the overall analysis of drilling fluids shows that the 60:40 OWR is the better in terms of sagging, filtrate loss and hole cleaning performance.

Study on the Manufacture of Microfluidic Chip with Coated Glass

2012 ◽  
Vol 548 ◽  
pp. 254-257 ◽  
Author(s):  
Yan He ◽  
Bai Ling Huang ◽  
Yong Lai Zhang ◽  
Li Gang Niu
Keyword(s):  
Microfluidic Chip ◽  
Low Cost ◽  
Microfluidic Channel ◽  
Critical Factor ◽  
Wet Etching ◽  
Microfluidic Chips ◽  
Etching Technique ◽  
Chip Quality ◽  
Wet Chemical ◽  
Wet Chemical Etching

In this paper, a simple and facile technique for manufacturing glass-based microfluidic chips was developed. Instead of using expensive dry etching technology, the standard UV lithography and wet chemical etching technique was used to fabricate microchannels on a K9 glass substrate. The fabrication process of microfluidic chip including vacuum evaporation, annealing, lithography, and BHF (HF-NH4F-H2O) wet etching were investigated. Through series experiments, we found that anneal was the critical factor for chip quality. As a representative example, a microfluidic channel with 20 m of depth, and 80 m of width was successfully prepared, and the channel surfaces are quite smooth. These results present a simple, low cost, flexible and easy way to fabricate glass-based microfluidic chips.

On-Chip Fabrication of None-Dead-Volume Microtips for ESI-MS Applications

2007 ◽  
Vol 121-123 ◽  
pp. 611-614
Author(s):  
Che Hsin Lin ◽  
Jen Taie Shiea ◽  
Yen Lieng Lin
Keyword(s):  
Surface Tension ◽  
Low Cost ◽  
Microfluidic Channel ◽  
Dead Volume ◽  
Esi Ms ◽  
Rapid Fabrication ◽  
Chip Fabrication ◽  
Novel Method ◽  
On Chip ◽  
Highly Uniform

This paper proposes a novel method to on-chip fabricate a none-dead-volume microtip for ESI-MS applications. The microfluidic chip and ESI tip are fabricated in low-cost plastic based materials using a simple and rapid fabrication process. A constant-speed-pulling method is developed to fabricate the ESI tip by pulling mixed PMMA glue using a 30-μm stainless wire through the pre-formed microfluidic channel. The equilibrium of surface tension of PMMA glue will result in a sharp tip after curing. A highly uniform micro-tip can be formed directly at the outlet of the microfluidic channel with minimum dead-volume zone. Detection of caffeine, myoglobin, lysozyme and cytochrome C biosamples confirms the microchip device can be used for high resolution ESI-MS applications.

Properties of Mouse Cutaneous Rapidly Adapting Afferents: Relationship to Skin Viscoelasticity

2004 ◽  
Vol 92 (2) ◽  
pp. 1236-1240 ◽  
Author(s):  
P. Grigg ◽  
D. R. Robichaud ◽  
Z. Del Prete
Keyword(s):  
Viscoelastic Material ◽  
Material Properties ◽  
Viscoelastic Properties ◽  
Mechanical Response ◽  
Loss Modulus ◽  
Multiple Logistic Regression Analysis ◽  
Rate Of Change ◽  
Volterra Model ◽  
Lower Sensitivity ◽  
Dynamic Stimuli

When skin is stretched, stimuli experienced by a cutaneous mechanoreceptor neuron are transmitted to the nerve ending through the skin. In these experiments, we tested the hypothesis that the viscoelastic response of the skin influences the dynamic response of cutaneous rapidly adapting (RA) neurons. Cutaneous RA afferent neurons were recorded in 3 species of mice (Tsk, Pallid, and C57BL6) whose skin has different viscoelastic properties. Isolated samples of skin and nerve were stimulated mechanically with a dynamic stretch stimulus, which followed a pseudo Gaussian waveform with a bandwidth of 0–60 Hz. The mechanical response of the skin was measured as were responses of single RA cutaneous mechanoreceptor neurons. For each neuron, the strength of association between spike responses and the dynamic and static components of stimuli were determined with multiple logistic regression analysis. The viscoelastic material properties of each skin sample were determined indirectly, by creating a nonlinear (Wiener–Volterra) model of the stress–strain relationship, and using the model to predict the complex compliance (i.e., the viscoelastic material properties). The dynamic sensitivity of RA mechanoreceptor neurons in mouse hairy skin was weakly related to the viscoelastic properties of the skin. Loss modulus and phase angle were lower (indicating a decreased viscous component of response) in Tsk and Pallid than in C57BL6 mice. However, RA mechanoreceptor neurons in Tsk and Pallid skin did not differ from those in C57 skin with regard to their sensitivity to the rate of change of stress or to the rate of change of incremental strain energy. They did have a decreased sensitivity to the rate of change of tensile strain. Thus the skin samples with lower dynamic mechanical response contained neurons with a somewhat lower sensitivity to dynamic stimuli.

scholarly journals A Modular Toolkit to Fabricate Microfluidic Devices for 3D Cell Culture and Near Real-time Measurements

2020 ◽  
Author(s):  
Giraso Kabandana ◽  
Adam Michael Ratajczak ◽  
Chengpeng Chen
Keyword(s):  
Cell Culture ◽  
Real Time ◽  
Low Cost ◽  
New Technology ◽  
Microfluidic Channel ◽  
3D Cell Culture ◽  
Microfluidic Devices ◽  
In Vitro Cell Cultures ◽  
Scoring Tools

Microfluidic technology has tremendously facilitated the development of in vitro cell cultures and studies. Conventionally, microfluidic devices are fabricated with extensive facilities by well-trained researchers, which hinders the widespread adoption of the technology for broader applications. Enlightened by the fact that low-cost microbore tubing is a natural microfluidic channel, we developed a series of adaptors in a toolkit that can twine, connect, organize, and configure the tubing to produce functional microfluidic units. Three subsets of the toolkit were thoroughly developed: the tubing and scoring tools, the flow adaptors, and the 3D cell culture suite. To demonstrate the usefulness and versatility of the toolkit, we assembled a microfluidic device and successfully applied it for 3D macrophage cultures, flow-based stimulation, and automated near real-time quantitation with new knowledge generated. Overall, we present a new technology that allows simple, fast, and robust assembly of customizable and scalable microfluidic devices with minimal facilities, which is broadly applicable to research that needs or could be enhanced by microfluidics.

Low-Cost Microfluidic Channel Fabrication for Lab-on-a-Chip Application Using Optimized SU-8 Soft Lithography

2021 ◽  
Author(s):  
Md. Fazlay Rubby ◽  
Varsha Namboodiri ◽  
Mohammad Salman Parvez ◽  
Nazmul Islam
Keyword(s):  
Soft Lithography ◽  
Low Cost ◽  
Microfluidic Channel ◽  
Lab On A Chip

Design and Fabrication of 3D Printed Reconfigurable Metamaterial-inspired Structures

2019 ◽  
Vol 2019 (1) ◽  
pp. 000595-000598
Author(s):  
Saranraj Karuppuswami ◽  
Avi Rajendra-Nicolucci ◽  
Saikat Mondal ◽  
Mohd Ifwat Mohd Ghazali ◽  
Premjeet Chahal
Keyword(s):  
High Temperature ◽  
Small Volume ◽  
Ring Resonator ◽  
Low Cost ◽  
Microfluidic Channel ◽  
Split Ring Resonator ◽  
Split Ring ◽  
Liquid Samples ◽  
Volatile Organic ◽  
3D Printed

Abstract In this paper, 3D printing is used as an alternative manufacturing technique to fabricate metamaterial-inspired RF structures for liquid profiling. A dual split-ring resonator (SRR) based sensor tag is designed and integrated with a microfluidic channel for detecting different liquid samples. The sensor is 3D printed using a high-temperature resin and metallized using a custom developed metal patterning process. The sensor requires a very small volume of 8.6 μL of sample under test for detection. The resonance frequency of the SRR changes with change in sample loading and the shift is monitored for sample profiling. Different volatile organic compounds are introduced and the shift is monitored demonstrating the sensitivity of the proposed tag. The low-cost, real-time nature of the tag makes it an ideal choice for monitoring liquids along the supply chain.

Thermomechanical Design for Fine Pitch 3D-IC Packages

2012 ◽  
Vol 2012 (1) ◽  
pp. 001001-001009 ◽  
Author(s):  
Akihiro Horibe ◽  
Sayuri Kohara ◽  
Kuniaki Sueoka ◽  
Keiji Matsumoto ◽  
Yasumitsu Orii ◽  
...  
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Low Cost ◽  
High Stress ◽  
High Viscosity ◽  
Thermomechanical Properties ◽  
Design Parameters ◽  
Element Analysis ◽  
Package Design ◽  
Fine Pitch ◽  
Silicon Vias

Low stress package design is one of the greatest challenges for the realization of reliable 3D integrated devices, since they are composed of elements susceptible to failures under high stress such as thin dies, metal through silicon vias (TSVs), and fine pitch interconnections. In variety of package components, an organic interposer is a key to obtain low cost modules with high density I/Os. However, the large mismatch in coefficient of thermal expansion (CTE) between silicon dies and organic laminates causes high stress in an organic package. The major parametric components in 3D devices are dies with /without Cu-TSVs, laminates, bumps, and underfill layers. Especially, the die thicknesses and underfill properties are ones of the parameters that give us some range to control as package design parameters. In general, the underfill material with a high modulus and a low CTE is effective in reducing the stress in solder interconnections between the Si die and the laminate. However, the filler content of underfill materials with such mechanical properties generally results in high viscosity. The use of high viscous materials in between silicon dies in 3D modules can degrade process ability in 3D integration. In this study, we show that the interchip underfills in 3D modules have a wider mechanical property window than in 2D modules even with fine pitch interconnections consisting mostly of intermetallic compounds (IMCs). Also the finite element analysis results show that the optimization of the structural or thermomechanical properties of organic laminates and interchip underfill contributes to reduction of stressing thinned silicon dies which may have some risks to the device performance.

Characterization of viscoelastic properties of minced beef meat thawed by ohmic and conventional methods

2019 ◽  
Vol 26 (4) ◽  
pp. 277-290 ◽  
Author(s):  
Mutlu Cevik ◽  
Filiz Icier
Keyword(s):  
Ambient Temperature ◽  
Viscoelastic Properties ◽  
Cold Water ◽  
Complex Modulus ◽  
Loss Modulus ◽  
Complex Viscosity ◽  
Creep Recovery ◽  
Recoverable Compliance ◽  
Meat Samples ◽  
Minced Meat

Frozen minced meat samples having fat contents of 2%, 10% and 18% were thawed using different methods (refrigeration thawing at ambient temperature of +4 ℃, under running cold water (+4 ℃) thawing, ohmic thawing for 10, 13 and 16 V/cm). Viscoelastic properties were determined by using rheological tests (oscillation and creep/recovery tests). Storage modulus, loss modulus, complex modulus, loss tangent, dynamic viscosity and complex viscosity values of minced meat samples increased as fat content increased. As frequency value increased, the modulus values of meat samples increased but dynamic and complex viscosity values of the samples decreased. The minced meat samples thawed by different methods had recoverable compliance values. The compliance values of meat samples during creep region can be well characterized by Burgers model. Ohmic thawing can be used as an alternative thawing method since it resulted in similar rheological properties of minced meat samples compared to refrigeration thawing at ambient temperature of +4 ℃ and under running cold water (+4℃) thawing.

Multi-Layer Photopolymer Micromachining

2005 ◽  
Vol 872 ◽  
Author(s):  
J. R. Huang ◽  
B. Bai ◽  
J. Shaw ◽  
T. N. Jackson ◽  
C. Y. Wei ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Integrated Circuits ◽  
High Aspect Ratio ◽  
Low Cost ◽  
Solution Process ◽  
Microfluidic Channel ◽  
Width Ratio ◽  
Large Area ◽  
Additive Process ◽  
Infiltration Process

AbstractThis paper presents a novel method to create and integrate micro-machined devices and high aspect-ratio (height-to-width ratio) microstructures in which the microstructures are built up using multiple layers of photopolymer film and/or viscous solution. Very high aspect-ratio 2-and 3-dimensional (2-D and 3-D) microstructures were constructed by stacking photo-imageable polymer films. Such films may be dry films applied by lamination or solution layers applied by bar coating, or doctor blade coating. Photolithography is used in both cases to define the microstructure. This additive process of thin-film micromachining facilitates high aspect-ratio microstructure fabrication. We have demonstrated structures of up to 12-layers comprising 2-D arrays of deep trenches (180 μm deep and 25 μm wide) and a 2-layer SU-8 micro-trench array with an aspect ratio up to 36 on glass substrates. Miniaturized structures of interconnected reservoirs as small as 50 μm × 50 μm × 15 μm (∼38 pico liter storage capacity) are also being fabricated, along with a novel 5-layer microfluidic channel array and a vacuum-infiltration process for fluid manipulation. This method has the potential to create functional large-area micro-devices at low-cost and with increased device flexibility, durability, prototyping speed, and reduced process complexity for applications in optoelectronics, integrated detectors, and bio-devices. The novel multi-layer photopolymer dry film and solution process also allows microstructures in micro-electro-mechanical systems (MEMS) to be built with ease and provides the functionality of MEMS integration with electronic devices and integrated circuits (ICs).

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