Paper-based continuous flow microfluidic (p-CMF) devices were first invented by Müller and Clegg in 1949 [1]; We give some examples of lab-on-a-chip applications using programmable paper-based microfluidic devices.
Fabrication of p-CMF Devices
The resolution of the cut depends on the sharpness of the blade and the hardness of the paper. Reprinted with permission from the authors of [48]. a) Schematic of the fabrication process, including relief, for the p-CMF device.
Fabrication of p-DMF Devices
Parylene-C, a reliable dielectric material for use in electronics, is commonly used as a dielectric layer for p-DMF devices [3,4,28]. Another material, a PDMS thin layer, can be prepared by spin coating and used as a dielectric layer for a p-DMF chip [68].
Strategies for Programming the Delivery of a Fluid Sample in p-CMF Devices
Hydrophobic materials are typically formed into paper channels to regulate fluid flow in p-CMF devices. Hydrophobic patterns in the paper channel act as barriers to arrest the flow of liquid (Figure 11).
Droplet Manipulations in p-DMF Devices
Biomarker Detection by Using Programmable p-CMF Devices
For lateral flow analysis, a sponge was incorporated into the p-CMF device to reduce the flow of the liquid sample. With this control technique, the transport of fluid samples in sequence to the detection zone for the detection of the malaria protein PfHRP2 was realized.
Biomarker Detection by Using Programmable p-DMF Devices
A P-CMF device was fabricated by placing dry pullulan films containing reagents on paper and was successfully used for sequential sample delivery for multi-step assays for the detection of pH, drugs (methamphetamine-like compounds), and intracellular bacterial enzymes (secondary amines) [106]. Challenges and Future Directions of Programmable Paper-Based Microfluidics Although paper-based microfluidics have made significant progress related to their.
Challenges and Future Directions of Programmable Paper-Based Microfluidic Devices Although paper-based microfluidic devices have made significant progress related to their
Conclusions and Outlook
Experimental Analysis of Manufacturing Parameters in the Development of Microfluidic Paper-Based Analytical Devices (μPADs).Micromachines2017,8. Low cost and multiplexed sandwich chemiluminescence immunoassay on microfluidic paper-based analytical device. Lab Chip.
Tangential Flow Microfiltration for Viral Separation and Concentration
- Introduction
- Materials and Methods 1. Materials
- Results
- Discussion
- Conclusions
A thin and straight microchannel was connected to the upper outlet of the filter device to control the flow resistance on the tangential flow path. After membrane functionalization, a resistive channel was connected to the upstream outlet of the filtration device to add resistance to flow to the tangential flow path.
Portable Rice Disease Spores Capture and Detection Method Using Diffraction Fingerprints on
Microfluidic Chip
Materials and Methods 1. Design of Microfluidic Chip
Due to the force, the two particles of different sizes deviate from the rail in two different directions, resulting in the initial separation of the two particles. The shape and design principle of the first and second structures are the same, so L3 must be smaller than L4. The concentration of spores in the air is very low, so 40 particles (2 μm particles and 16 μm particles, 20 each) were distributed at regular intervals from the center of the particle inlet to the edge.
In addition, a drawer-type sample tray was designed to realize rapid replacement of the microfluidic chip. To design a spore detection system based on spore diffraction fingerprint, the acquisition and processing of the diffraction fingerprint image were automatic. AP is the average relative light intensity of two peaks (P1, P2) in a single spore fraction fingerprint.
Results and Discussion
Figure 6a is the simulation result of the separation and enrichment effect of two kinds of particles, 20 particles each. As shown in Figure 6, the principle of separation and enrichment of the first structure is first analyzed. The mixed gas enters the microchannel from the inlet of the microfluidic chip and acquires an initial velocity from horizontal to the right.
Reducing the size of L3 accelerates the particles, increasing the acceleration of the particles by 2 μm and increasing the centrifugal force to enter collection tank 2. MATLAB was used to calculate the diffraction fingerprint with the same parameter setting as that of the experimental setup. Mixed gas was then pumped into the designed microfluidic chip and the performance of the device was verified by taking pictures.
Conclusions
Identification of a specific molecular marker for the rice blast resistance gene Pigm and molecular breeding of thermo-sensitive genetic male sterile leaf color marker lines.Mol. Early prediction of rice blast disease using long short-term memory Recurrent neural networks.Sustainability2017,10, 34. Effector-mediated suppression of chitin-activated immunity by Magnaporthe oryzae is required for rice blast disease.Plant Cell.
A simple and low-cost device that performs blood cell counting based on the lensless shadow imaging technique. Sens. An approach for online cell viability detection based on lensless cell diaxial fingerprint characteristics. Biosens. Low-cost telemedicine device that performs cell and particle size measurement based on lensless shadow imaging technology. Biosens.
Detection of Cigarette Smoke Using a Surface-Acoustic-Wave Gas Sensor with
Materials and Methods
In this research, sensing materials of two types were chosen for cigarette smoke detection. The cigarette smoke was drawn with a pump (Thomas, diaphragm pump 2002, 400 ml/min) into a sampling bag. In addition to the detection of pure 3-ethenylpyridine, cigarette smoke is also detected with the same system and the same sensor material.
It shows that the frequency response decreases continuously as the cigarette smoke flows into the microchamber. Figure 7b is the frequency response for detecting cigarette smoke with O-HMC over five consecutive cycles. The surface acoustic wave (SAW) gas sensor coated with oxidized hollow mesoporous carbon nanospheres (O-HMC) detects the second-hand smoke marker (3-ethenylpyridine) and cigarette smoke.
A Microfluidic Split-Flow Technology for Product Characterization in Continuous Low-Volume
Materials and Methods 1. Mixing Chip
Microsystem fabrication and glass structuring was performed by femtosecond laser ablation (microSTRUCT c; 3D Micromac AG, Chemnitz, Germany). With this arrangement, the organic phase was concentrated in the middle of the channel and contact with the wall was limited to prevent fouling. Thus, a better quality of mixing resulted in a smaller and more homogeneous size of the precipitated particles.
A camera was used to measure the plug size and allowed adjustment of the particle/plug size. Most of the product stream was directed to a pressure bottle without passing the detector. Additional pressure-controlled vials are connected to the inlet and outlet of the buffer supply channel.
Results and Discussion 1. Particle Concentration
Histograms of the maximum peak intensities measured in experiments with different mixing ratios are shown in Figure 3a. The reduction in plug size leads to a reduction in average particle size of up to 29%. The reciprocal residence time histograms show a very prominent peak in all experiments (Figure 3b).
Likewise, a much faster and unstable change in the residence time and the number of particles was detected (Figure 5d), which can be interpreted as clogging of the measuring channel. Transient changes in the particle synthesis were detected in different parameters and could be assigned to a specific time of the process. The critical part of the detection chip is the measurement channel with a nominal depth and width of 2μm.
Affordable Fabrication of Conductive Electrodes and Dielectric Films for a Paper-Based Digital
Materials and Methods 1. Chemicals and Materials
Before printing, the prepared ballpoint pen was inserted into terminal A of the digital plotter. The surface properties of the LLDPE dielectric film were observed using atomic force microscopy (AFM) (NanoStation, Pucotech, Seoul, Korea) and Fourier transform infrared spectroscopy (FT-IR) (Agilent Technologies, Cray 640 FTIR, Santa Clara, CA, USA). In addition, the thickness of the printed electrode (single printing) was 450 ± 50 nm, which is suitable for DMF use (Fig. 2e).
This is a limitation of the contact printing technique in printing multi-layer designs. The AFM data showed that the surface of the as-prepared LLDPE film contained several defects (Figure 3a,b). In preparing the dielectric layer for the paper-based DMF chip, we used commercial food grade wrap made from LLDPE.
Magnetically Induced Flow Focusing of
Non-Magnetic Microparticles in Ferrofluids under Inclined Magnetic Fields
Theoretical Analysis
In low Reynolds number microfluidic systems, the hydrodynamic drag force, Fd, is related to the size and velocity of the particle and the drag coefficient. Fd=3πηDp(up−uf)CD, (2) whereη is the viscosity of suspensions;Dpis the diameter of the non-magnetic microparticles;upand ufare the velocities of microparticles and suspensions, respectively. Brownian motion affects the motion of the particle only when the particle diameter is small enough (less than the critical diameter of the particle) or the F-map applied to the particle is weak [12].
When the applied magnetic field is 1 T, the critical diameter of the Fe4O3 particles in water can be calculated to be 40 nm according to the above formula. Moreover, the interactions between the particle itself and with liquid could usually be neglected in a low-concentration state. Figure 2 illustrates the focusing mechanism for non-magnetic particles in the magnet-microchannel system, where particles are pushed away from the high-field region and concentrated along the centerline of the channel under the influence of two magnets of the same opposite polarity.
Materials and Methods
Results and Discussion 1. Magnetic Field
Based on the above analysis, we can calculate the magnetic field strength and the magnetic force acting on the particle in the center of the channel, i.e. y= 0. For example, the magnetic field strength in the x direction of the left side is reduced from . Figure 6e,f show the total magnetic field strength and the total magnetic force at the center of the channel, respectively.
Therefore, the flow rate of the particles can be expressed as upx=umx+uf x= Fmx. For side-direction, the effect is to push the particles towards the center of the channel. We also calculated the effect of the flow field on the particle focusing, i.e. the critical flow rate.
An Optically Induced Dielectrophoresis
ODEP)-Based Microfluidic System for the Isolation of High-Purity CD45 neg /EpCAM neg Cells from the
Results and Discussions
Characteristic features of the proposed ODEP-based microfluidic system for the isolation and purification of CD45neg/EpCAMneg cells. In this study, the performance of the proposed ODEP microfluidic system for the isolation of CD45neg/EpCAMneg cells was experimentally assessed. Comparison of the cancer-related gene expression of the CD45neg/EpCAMneg cells isolated from the blood samples of healthy donors and head and neck cancer patients.
Cancer-related gene expression of CD45neg/EpCAMnegnucleated cells in the two sample groups was analyzed and then compared. Table 1 provides a summary of the results of this comparison (detailed experimental results are provided as a supplementary table: Table S1). In this study, as a whole, the expression of EMT-, MRP- and CSC-related genes of CD45neg/EpCAM nucleated cells isolated from blood samples of cancer patients and healthy donors was reported for the first time.
MDPI
