Characterization of High-Throughput Capillary-Based Microfluidic Devices for Lab-on-Chip Integrated Optics Detections

2014 ◽  
Vol 635-637 ◽  
pp. 658-661
Author(s):  
Carlos Honrado ◽  
Tao Dong

The characterization of novel portable microfluidic devices, with capillary phenomena as filling process, was presented. Created for monitoring multiplexed chemiluminescence (CL) reactions, the devices are amenable for integration with organic photodiodes (OPDs) for future incorporation in microelectromechanical systems (MEMS). Using finite element method (FEM), four designs of microfluidic chips were simulated. The parallel design, despite its quick total filling time (TFT), presented a non-uniform filling process and a non-compact structure. The series design was the most compact structure studied. However, it cannot be used in CL reactions with multiple analytes in common, which is a major drawback. Regarding the parallel-series, it solved some of the problems presented in previous designs but its high TFT and non-compactness make it a less attractive solution for a portable microfluidic device. Finally, the optimized parallel design proved to be the best design, presenting a quick TFT, high compactness and the capability to have CL reactions sharing analytes.

2021 ◽  
Author(s):  
Heba Mansour ◽  
Ahmed M.R. Fath El-Bab ◽  
Emad A. Soliman ◽  
Ahmed L. Abdel-Mawgood

Abstract Microfluidic devices are a rising technology to automatize chemical and biological operations. In this context, laser ablation has significant potential for polymer-based microfluidic platforms' fast and economical manufacturing. Nevertheless, the manufacturing of epoxy-based microfluidic chips is considered highly cost full due to demand for cleanroom facilities that utilize expensive equipment and lengthy processes. Therefore, this study targeted investigating the feasibility of epoxy resins to be fabricated as a lab-on-chip using carbon dioxide laser ablation. The chemical structural properties and thermal stability of the plain epoxy resins were characterized by Fourier transform infrared spectral analysis (FT-IR) and thermogravimetric analysis (TGA). Moreover, a specific migration test was performed to quantify potential migrants by gas chromatography coupled to mass spectrometry (GC-MS) to prove that the cured epoxy resin would not release unreacted monomers to the biological solution test, which caused inhibition of the sensitive biological reactions. By investigating the impact of this process on microchannels' dimensions and quality, a laser technique using CO2 laser was used in vector mode to engrave into a transparent epoxy resin chip. The resulting microchannels were characterized using 3D Laser microscopy. The outcomes of this study showed considerable potential for laser ablation in machining the epoxy-based chips, whereas the microchannels were produced with minor bulges' height (0.027 µm) with no clogging. Moreover, a reasonable depth of 99.31 µm with roughness (Ra) of 14.52 µm was obtained at a laser speed of 5 mm/s and laser power of 1.8 W. This process can produce epoxy resin-based microfluidic chips without the need for cleanroom facilities that require expensive equipment and lengthy process.


Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1137
Author(s):  
Xinqi Zheng ◽  
Xiudong Duan ◽  
Xin Tu ◽  
Shulan Jiang ◽  
Chaolong Song

It has been demonstrated that microalgae play an important role in the food, agriculture and medicine industries. Additionally, the identification and counting of the microalgae are also a critical step in evaluating water quality, and some lipid-rich microalgae species even have the potential to be an alternative to fossil fuels. However, current technologies for the detection and analysis of microalgae are costly, labor-intensive, time-consuming and throughput limited. In the past few years, microfluidic chips integrating optical components have emerged as powerful tools that can be used for the analysis of microalgae with high specificity, sensitivity and throughput. In this paper, we review recent optofluidic lab-on-chip systems and techniques used for microalgal detection and characterization. We introduce three optofluidic technologies that are based on fluorescence, Raman spectroscopy and imaging-based flow cytometry, each of which can achieve the determination of cell viability, lipid content, metabolic heterogeneity and counting. We analyze and summarize the merits and drawbacks of these micro-systems and conclude the direction of the future development of the optofluidic platforms applied in microalgal research.


2021 ◽  
Vol 25 (8) ◽  
Author(s):  
Yanwei Wang ◽  
Michael Seidel

AbstractFabrication of 3D microfluidic devices is normally quite expensive and tedious. A strategy was established to rapidly and effectively produce multilayer 3D microfluidic chips which are made of two layers of poly(methyl methacrylate) (PMMA) sheets and three layers of double-sided pressure sensitive adhesive (PSA) tapes. The channel structures were cut in each layer by cutting plotter before assembly. The structured channels were covered by a PMMA sheet on top and a PMMA carrier which contained threads to connect with tubing. A large variety of PMMA slides and PSA tapes can easily be designed and cut with the help of a cutting plotter. The microfluidic chip was manually assembled by a simple lamination process.The complete fabrication process from device design concept to working device can be completed in minutes without the need of expensive equipment such as laser, thermal lamination, and cleanroom. This rapid frabrication method was applied for design of a 3D hydrodynamic focusing device for synthesis of gold nanoparticles (AuNPs) as proof-of-concept. The fouling of AuNPs was prevented by means of a sheath flow. Different parameters such as flow rate and concentration of reagents were controlled to achieve AuNPs of various sizes. The sheet-based fabrication method offers a possibility to create complex microfluidic devices in a rapid, cheap and easy way.


2001 ◽  
Vol 687 ◽  
Author(s):  
Jürgen Brünahl ◽  
Alex M. Grishin ◽  
Sergey I. Khartsev ◽  
Carl Österberg

AbstractWe report on comprehensive characterization of piezoelectric shear mode inkjet actuators micromachined into bulk Pb(Zr0.53Ti0.47)O3 (PZT) ceramics. The paper starts with an overview of different inkjet technologies such as continuous jet and drop-on-demand systems, whereat main attention is turned on piezoelectric systems particularly Xaar-type shear mode inkjet color printheads. They are an example of complex microelectromechanical systems (MEMS) and comprise a ferroelectric array of 128 active ink channels (75νm wide and 360νm deep). Detailed information about manufacturing and principles of operation are given. Several techniques to control manufacturing processes and to characterize properties of the piezoelectric material are described: dielectric spectroscopy to measure dielectric permittivity ε and loss tanσ; ferroelectric hysteresis P-E loop tracing to get remnant polarization Pr and coercive field Ec, and a novel pulsed technique to quantify functional properties of the PZT actuator such as acoustic resonant frequencies and electromechanical coupling factor. Stroboscope technique has been employed to find correlation between the degradation of ink-jet performance and heat/high voltage treatment resulting in ferroelectric fatigue.


2016 ◽  
Vol 47 (2) ◽  
pp. 233-251 ◽  
Author(s):  
Zhou Zhao ◽  
Weiren Bao ◽  
Youbo Di ◽  
Jinming Dai

A new flame-retardant protein viscose fiber with safely wearing performance has been prepared through blending protein solution, flame retardant (hexaphenoxycyclotriphosphazene) and viscose spinning solution, in which wool protein was used and added to spinning solution on the basis of 16% flame retardant, and the properties of the fiber were investigated. The product has more compact structure inside the fiber and evenly scattered small pores on the surface. Flame-retardant protein viscose fiber can reach the flame-retardant standard both before and after 30 times wash test, and the mechanical strength of the fiber was also improved. The introduction of hexaphenoxycyclotriphosphazene lowered the primary decomposition temperature of viscose fiber, reduced its weight loss. The flame-retardancy of the fiber can be improved by the introduction of protein. In thermal processes, the major product of thermal decomposition was CO2, no hazardous and noxious gases were released. Due to the introduction of protein, moisture regain of the fiber is a little lower than that of viscose fiber, but higher than flame-retardant viscose fiber. Warmth retention property was also improved. Friction coefficient of the product is lower than that of flame-retardant viscose fiber. Bulking intensity was increased, which is better than that of viscose fiber.


2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Sina Hamian ◽  
Andrew M. Gauffreau ◽  
Timothy Walsh ◽  
Jungchul Lee ◽  
Keunhan Park

This paper reports the frequency-dependent electrothermal behaviors of a freestanding doped-silicon heated microcantilever probe operating under periodic (ac) Joule heating. We conducted a frequency-domain finite-element analysis (FEA) and compared the steady periodic solution with 3ω experiment results. The computed thermal transfer function of the cantilever accurately predicts the ac electrothermal behaviors over a full spectrum of operational frequencies, which could not be accomplished with the 1D approximation. In addition, the thermal transfer functions of the cantilever in vacuum and in air were compared, through which the frequency-dependent heat transfer coefficient of the air was quantified. With the developed FEA model, design parameters of the cantilever (i.e., the size and the constriction width of the cantilever heater) and their effects on the ac electrothermal behaviors were carefully investigated. Although this work focused on doped-Si heated microcantilever probes, the developed FEA model can be applied for the ac electrothermal analysis of general microelectromechanical systems.


Author(s):  
Xiao Wang ◽  
Jian Zhou ◽  
Nivedita Nivedita ◽  
Ian Papautsky
Keyword(s):  

2005 ◽  
Vol 287 ◽  
pp. 200-205 ◽  
Author(s):  
Ji Yeon Park ◽  
S.M. Kang ◽  
Weon Ju Kim ◽  
Woo Seog Ryu

To obtain a dense SiCf/SiC composite by the chemical vapor infiltration (CVI) process, whisker growing before matrix filling was applied, which is called the whisker growing assisted CVI process. The whisker growing and matrix filling processes were carried out using MTS (CH3SiCl3) and H2 as source and diluent gases, respectively. Tyranno-SATM was used as a reinforced substrate. Characterizations of SiC whisker grown during the in situ whisker growing process have been investigated. The weight gain rates with the matrix filling time and the density of composites was measured. The flexural strength with the thickness of the pyrolytic carbon (PyC) interlayers has been evaluated. b-SiC whiskers with many stacking faults were grown well in the Tyranno SATM fabrics. Tyranno-SA/SiC composite with a PyC interlayer thickness of 150 nm had a flexural strength of 610 MPa and the density of 2.71 g/cm3.


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