The applications of pressure-sensitive paint in microfluidic systems

Huang, Chuanjun; Matsuda, Yu; Gregory, James W.; Nagai, Hiroki; Asai, Keisuke

doi:10.1007/s10404-014-1510-z

Cited by 32 publications

(14 citation statements)

References 55 publications

(54 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent approaches include utilizing pressure-sensitive paint (PSP) to resolve the pressure data and liquid crystal technique for shear stress measurements over surfaces in microfluidic systems. 5,6 However, these coating-based methods are constrained to measurements on surface and often required tedious data reduction procedures. In comparison, flow-induced birefringence offers a straight-forward representation of the stress field, benefiting from the stress-optical law that states a linear relationship between the principal stress difference and the amount of birefringence.…”

Section: Introductionmentioning

confidence: 99%

Measurements of flow-induced birefringence in microfluidics

Sun

Huang

2016

Biomicrofluidics

View full text Add to dashboard Cite

In this study, we demonstrate the use of a microscopic circular polariscope to measure the flow-induced birefringence in a microfluidic device that represents the kinematics of fluid motion optically. Unlike the commercial birefringence microscope employed in the previous studies, our approach is able to provide direct measurement of retardance, which quantifies the difference in refractive index of the fluid experienced by the ordinary and extraordinary rays, from one single image frame. This capability facilitates unsteady full-field quantitation of flow-induced birefringence in microfluidics that has never been achieved before. At low flow rates, we find that the value of the retardance is independent of the microfluidic design and proportional to the nominal strain rates. This linearity bridges the measurement of birefringence and the deformation rate in the microflow environment, which yields the stress information of the fluid flow. In addition, the μPIV results confirm that both extensional and shear strain rates contribute to the flow-induced birefringence so that the retardance distribution can be used to represent the field of the principal strain rate in a microfluidic device. The outcome of this study proves that our approach provides a non-invasive method that enables an intuitive full-field representation of stress in the instantaneous flow field in a microfluidic device.

show abstract

Section: Introductionmentioning

confidence: 99%

Measurements of flow-induced birefringence in microfluidics

Sun

Huang

2016

Biomicrofluidics

View full text Add to dashboard Cite

show abstract

“…Several studies focused on the integrated pressure sensor and various methods have been reported for discrete pressure detection inside microchannels. Most of them are based on classical mechanical measurement principles . Moving parts, e.g., membranes, are used as a signal transducer.…”

Section: Integrated Sensorsmentioning

confidence: 99%

Smart Equipment – A Perspective Paper

Kockmann

Bittorf

Krieger

et al. 2018

Chemie Ingenieur Technik

View full text Add to dashboard Cite

Chemical equipment has to form a robust and efficient process space and was developed over the last centuries to very sophisticated, often highly specialized devices. With the upcoming information technology new opportunities arise with integrated sensors, and advanced control systems. Smart equipment is designed in form of intelligent modules. Furthermore, adaptive and integrated actuators convert the control signals to directly influence the process, thus, they can be described as responsive equipment. This contribution will give an overview of some activities in this field.

show abstract

“…In order to simplify the structure, membraneless pressure methods have also been proposed [ 30 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ]. According to the measuring position, these methods can be generally classified into two categories.…”

Section: Introductionmentioning

confidence: 99%

“…According to the measuring position, these methods can be generally classified into two categories. The first category is direct measurement inside the microchannel, for example, the pressure-sensitive paint (PSP) method using luminescence emitted from air pressure-sensitive molecules [ 30 , 47 , 48 , 49 , 50 ] and the deformable elastic microballoon method [ 51 ], both of which are optical. The second category is based on a sealed side channel connected to the microchannel at the location where the pressure is to be measured, for example, the flexible liquid metal electrodes-based capacitive method [ 52 ] and trapped air compression methods [ 30 , 53 , 54 , 55 , 56 , 57 ].…”

Section: Introductionmentioning

confidence: 99%

An Easy Method for Pressure Measurement in Microchannels Using Trapped Air Compression in a One-End-Sealed Capillary

Shen

et al. 2020

Micromachines

View full text Add to dashboard Cite

Pressure is one basic parameter involved in microfluidic systems. In this study, we developed an easy capillary-based method for measuring fluid pressure at one or multiple locations in a microchannel. The principal component is a commonly used capillary (inner diameter of 400 μm and 95 mm in length), with one end sealed and calibrated scales on it. By reading the height (h) of an air-liquid interface, the pressure can be measured directly from a table, which is calculated using the ideal gas law. Many factors that affect the relationship between the trapped air volume and applied pressure (papplied) have been investigated in detail, including the surface tension, liquid gravity, air solubility in water, temperature variation, and capillary diameters. Based on the evaluation of the experimental and simulation results of the pressure, combined with theoretical analysis, a resolution of about 1 kPa within a full-scale range of 101.6–178 kPa was obtained. A pressure drop (Δp) as low as 0.25 kPa was obtained in an operating range from 0.5 kPa to 12 kPa. Compared with other novel, microstructure-based methods, this method does not require microfabrication and additional equipment. Finally, we use this method to reasonably analyze the nonlinearity of the flow–pressure drop relationship caused by channel deformation. In the future, this one-end-sealed capillary could be used for pressure measurement as easily as a clinical thermometer in various microfluidic applications.

show abstract

The applications of pressure-sensitive paint in microfluidic systems

Cited by 32 publications

References 55 publications

Measurements of flow-induced birefringence in microfluidics

Measurements of flow-induced birefringence in microfluidics

Smart Equipment – A Perspective Paper

An Easy Method for Pressure Measurement in Microchannels Using Trapped Air Compression in a One-End-Sealed Capillary

Contact Info

Product

Resources

About