A poly(dimethylsiloxane) viscometer for microliter power law fluids

Han, Zuoyan; Zheng, Bo

doi:10.1088/0960-1317/19/11/115005

Cited by 13 publications

(8 citation statements)

References 32 publications

(40 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…glycerin, blood plasma and ethanol) 53 and non-Newtonian fluids (i.e. PEO and blood), 54 the PDMS-based viscometer measured the fluid viscosity more consistently than conventional viscometers.…”

mentioning

confidence: 89%

“…51 Furthermore, the viscosity of a test fluid was automatically measured by monitoring the advancing meniscus in the channel through the use of three droplet sensing techniques, namely, a digital electrode, an analogue electrode and a thermal electrode. 52 To replace expensive silicon-glass devices, Zheng et al 53,54 introduced a PDMS viscometer for monitoring the advancing meniscus of a test liquid in a capillary channel. The wettability of the fluid on the PDMS surface did not affect the viscosity measurement because the capillary forces were cancelled out in the data analysis.…”

mentioning

confidence: 99%

See 1 more Smart Citation

In vitroandex vivomeasurement of the biophysical properties of blood using microfluidic platforms and animal models

Kang

Lee

2018

Analyst

View full text Add to dashboard Cite

Haemorheologically impaired microcirculation, such as blood clotting or abnormal blood flow, causes interrupted blood flows in vascular networks. The biophysical properties of blood, including blood viscosity, blood viscoelasticity, haematocrit, red blood bell (RBC) aggregation, erythrocyte sedimentation rate and RBC deformability, have been used to monitor haematological diseases. In this review, we summarise several techniques for measuring haemorheological properties, such as blood viscosity, RBC deformability and RBC aggregation, using in vitro microfluidic platforms. Several methodologies for the measurement of haemorheological properties with the assistance of an extracorporeal rat bypass loop are also presented. We briefly discuss several emerging technologies for continuous, long-term, multiple measurements of haemorheological properties under in vitro or ex vivo conditions.

show abstract

mentioning

confidence: 89%

mentioning

confidence: 99%

In vitroandex vivomeasurement of the biophysical properties of blood using microfluidic platforms and animal models

Kang

Lee

2018

Analyst

View full text Add to dashboard Cite

show abstract

“…To measure blood viscosity in a microfluidic device, blood is made to flow at a specific flow rate or velocity using several driving sources, such as syringe pumps, pressure sources [ 28 ], surface tension [ 29 , 30 , 31 , 32 ], and pipettes [ 33 ]. After that, as shown in Table 1 , several measurement techniques, including co-flowing streams [ 34 ], modified parallel flows [ 9 , 24 ], microflow compartments [ 35 , 36 ], reversal flow-switching [ 10 , 37 , 38 , 39 ], advancing meniscus [ 28 , 29 , 30 , 31 , 32 , 33 ], and electric impedance measurements [ 40 , 41 ], can be used to measure blood viscosity. Considering some critical issues, such as RBC clogging and precise flow-rate control and calibration, the modified parallel flows method (MPFM) [ 9 , 24 ] shows high potential for continuous measurement of blood viscosity.…”

Section: Introductionmentioning

confidence: 99%

Microfluidic-Based Technique for Measuring RBC Aggregation and Blood Viscosity in a Continuous and Simultaneous Fashion

Kang

2018

Micromachines

View full text Add to dashboard Cite

Hemorheological properties such as viscosity, deformability, and aggregation have been employed to monitor or screen patients with cardiovascular diseases. To effectively evaluate blood circulating within an in vitro closed circuit, it is important to quantify its hemorheological properties consistently and accurately. A simple method for measuring red blood cell (RBC) aggregation and blood viscosity is proposed for analyzing blood flow in a microfluidic device, especially in a continuous and simultaneous fashion. To measure RBC aggregation, blood flows through three channels: the left wide channel, the narrow channel and the right wide channel sequentially. After quantifying the image intensity of RBCs aggregated in the left channel () and the RBCs disaggregated in the right channel (), the RBC aggregation index (AIPM) is obtained by dividing by . Simultaneously, based on a modified parallel flow method, blood viscosity is obtained by detecting the interface between two fluids in the right wide channel. RBC aggregation and blood viscosity were first evaluated under constant and pulsatile blood flows. AIPM varies significantly with respect to blood flow rate (for both its amplitude and period) and the concentration of the dextran solution used. According to our quantitative comparison between the proposed aggregation index (AIPM) and the conventional aggregation index (AICM), it is found that AIPM provides consistent results. Finally, the suggested method is employed to obtain the RBC aggregation and blood viscosity of blood circulating within an in vitro fluidic circuit. The experimental results lead to the conclusion that the proposed method can be successfully used to measure RBC aggregation and blood viscosity, especially in a continuous and simultaneous fashion.

show abstract

“…Based on the microfluidic platform, several viscosity measurement methods such as extensional flow, 16 capacity sensor, 17 capillary force, 18,19 comparator, 20,21 quartz crystal microbalance (QCM), 22 laser-induced capillary wave, 23 and multiple microfluidic channels 24 have been recently proposed. Most of these methods were focused on pure liquids rather than blood including cellular components.…”

mentioning

confidence: 99%

“…Few of these methods have been applied to measure blood viscosity, only as a stand-alone approach. 19,24,25 Given that blood flow rate is not specified in a microvascular network, blood viscosities were routinely measured for wide ranges of shear rates, with the assumption that blood behaves as a nonNewtonian fluid. Thus, blood viscosity identification should be conducted at a specified flow rate, where blood circulates in a complex fluidic network.…”

mentioning

confidence: 99%

A microfluidic device for simultaneous measurement of viscosity and flow rate of blood in a complex fluidic network

2013

View full text Add to dashboard Cite

Blood viscosity has been considered as one of important biophysical parameters for effectively monitoring variations in physiological and pathological conditions of circulatory disorders. Standard previous methods make it difficult to evaluate variations of blood viscosity under cardiopulmonary bypass procedures or hemodialysis. In this study, we proposed a unique microfluidic device for simultaneously measuring viscosity and flow rate of whole blood circulating in a complex fluidic network including a rat, a reservoir, a pinch valve, and a peristaltic pump. To demonstrate the proposed method, a twin-shaped microfluidic device, which is composed of two half-circular chambers, two side channels with multiple indicating channels, and one bridge channel, was carefully designed. Based on the microfluidic device, three sequential flow controls were applied to identify viscosity and flow rate of blood, with label-free and sensorless detection. The half-circular chamber was employed to achieve mechanical membrane compliance for flow stabilization in the microfluidic device. To quantify the effect of flow stabilization on flow fluctuations, a formula of pulsation index (PI) was analytically derived using a discrete fluidic circuit model. Using the PI formula, the time constant contributed by the half-circular chamber is estimated to be 8 s. Furthermore, flow fluctuations resulting from the peristaltic pumps are completely removed, especially under periodic flow conditions within short periods (T < 10 s). For performance demonstrations, the proposed method was applied to evaluate blood viscosity with respect to varying flow rate conditions [(a) known blood flow rate via a syringe pump, (b) unknown blood flow rate via a peristaltic pump]. As a result, the flow rate and viscosity of blood can be simultaneously measured with satisfactory accuracy. In addition, the proposed method was successfully applied to identify the viscosity of rat blood, which circulates in a complex fluidic network. These observations confirm that the proposed method can be used for simultaneous measurement of viscosity and flow rate of whole blood circulating in the complex fluid network, with sensorless and label-free detection. Furthermore, the proposed method will be used in evaluating variations in the viscosity of human blood during cardiopulmonary bypass procedures or hemodialysis.

show abstract

A poly(dimethylsiloxane) viscometer for microliter power law fluids

Cited by 13 publications

References 32 publications

In vitroandex vivomeasurement of the biophysical properties of blood using microfluidic platforms and animal models

In vitroandex vivomeasurement of the biophysical properties of blood using microfluidic platforms and animal models

Microfluidic-Based Technique for Measuring RBC Aggregation and Blood Viscosity in a Continuous and Simultaneous Fashion

A microfluidic device for simultaneous measurement of viscosity and flow rate of blood in a complex fluidic network

Contact Info

Product

Resources

About