scholarly journals Influence of the Flow Rate in an Automated Microfluidic Electronic Tongue Tested for Sucralose Differentiation

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6194
Author(s):  
Maria L. Braunger ◽  
Igor Fier ◽  
Flávio M. Shimizu ◽  
Anerise de Barros ◽  
Varlei Rodrigues ◽  
...  
Keyword(s):  
Double Layer ◽  
Flow Rate ◽  
Printed Circuit Board ◽  
Electronic Tongue ◽  
Equivalent Circuit Model ◽  
Principal Component ◽  
Food Product ◽  
Circuit Board ◽  
Raw Data ◽  
Flow Rate Increase

Incorporating electronic tongues into microfluidic devices brings benefits as dealing with small amounts of sample/discharge. Nonetheless, such measurements may be time-consuming in some applications once they require several operational steps. Here, we designed four collinear electrodes on a single printed circuit board, further comprised inside a straight microchannel, culminating in a robust e-tongue device for faster data acquisition. An analog multiplexing circuit automated the signal’s routing from each of the four sensing units to an impedance analyzer. Both instruments and a syringe pump are controlled by dedicated software. The automated e-tongue was tested with four Brazilian brands of liquid sucralose-based sweeteners under 20 different flow rates, aiming to systematically evaluate the influence of the flow rate in the discrimination among sweet tastes sold as the same food product. All four brands were successfully distinguished using principal component analysis of the raw data, and despite the nearly identical sucralose-based taste in all samples, all brands’ significant distinction is attributed to small differences in the ingredients and manufacturing processes to deliver the final food product. The increasing flow rate improves the analyte’s discrimination, as the silhouette coefficient reaches a plateau at ~3 mL/h. We used an equivalent circuit model to evaluate the raw data, finding a decrease in the double-layer capacitance proportional to improvements in the samples’ discrimination. In other words, the flow rate increase mitigates the formation of the double-layer, resulting in faster stabilization and better repeatability in the sensor response.

Nanomonitor Technology for Glycosylation Analysis

2009 ◽  
Vol 1236 ◽  
Author(s):  
Gaurav Chatterjee ◽  
Manish Bothara ◽  
Srivatsa Aithal ◽  
Vinay J Nagraj ◽  
Peter Wiktor ◽  
...  
Keyword(s):  
Double Layer ◽  
Electrical Double Layer ◽  
Printed Circuit Board ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Protein Glycosylation ◽  
Circuit Board ◽  
Biological Macromolecules ◽  
Label Free ◽  
Alumina Membrane

AbstractChanges in protein glycosylation have great potential as markers for the early diagnosis of cancer and other diseases. The current analytical tools for the analysis of glycan structures need expensive instrumentation, advanced expertise, is time consuming and therefore not practical for routine screening of glycan biomarkers from human samples in a clinical setting.We are developing a novel ultrasensitive diagnostic platform called ‘NanoMonitor’ to enable rapid label-free glycosylation analysis. The technology is based on electrochemical impedance spectroscopy where capacitance changes are measured at the electrical double layer interface as a result of interaction of two molecules.The NanoMonitor platform consists of a printed circuit board with array of electrodes forming multiple sensor spots. Each sensor spot is overlaid with a nanoporous alumina membrane that forms a high density of nanowells. Lectins, proteins that bind to and recognize specific glycan structures, are conjugated to the surface of nanowells. When specific glycoproteins from a test sample bind to lectins in the nanowells, it produces a perturbation to the electrical double layer at the solid/liquid interface at the base of each nanowell. This perturbation results in a change in the impedance of the double layer which is dominated by the capacitance changes within the electrical double layer.The nanoscale confinement or crowding of biological macromolecules within the nanowells is likely to enhance signals from the interaction of glycoproteins with the lectins leading to a high sensitivity of detection with the NanoMonitor as compared to other electrochemical techniques.Using a panel of lectins, we were able to detect subtle changes in the glycosylation of fetuin protein as well as differentiate glycoproteins from normal versus cancerous cells. Our results indicate that NanoMonitor can be used as a cost-effective miniature electronic biosensor for the detection of glycan biomarkers.

Principle and structure of a printed circuit board process–based piezoelectric microfluidic pump integrated into printed circuit board

2019 ◽  
Vol 30 (17) ◽  
pp. 2595-2604 ◽  
Author(s):  
Dai-Hua Wang ◽  
Lian-Kai Tang ◽  
Yun-Hao Peng ◽  
Huai-Qiang Yu
Keyword(s):  
Flow Rate ◽  
Printed Circuit Board ◽  
Flow Characteristics ◽  
Circuit Board ◽  
Microfluidic Systems ◽  
Printed Circuit ◽  
Board Processes ◽  
Voltage Frequency ◽  
Instantaneous Flow Rate ◽  
Board Process

Considering mature printed circuit board processes, researches on microfluidic pumps that can be integrated into printed circuit board will provide a solution for further miniaturization and integration of microfluidic systems with low costs. The principle and structure of a printed circuit board process–based piezoelectric microfluidic pump integrated into printed circuit board are proposed and realized in this article. The printed circuit board process–based design and manufacturing technology of a piezoelectric microfluidic pump integrated into printed circuit board is researched utilizing printed circuit board as a platform. The flow characteristics of the fabricated microfluidic pump are experimentally tested. The research results show that the proposed principle and structure of the piezoelectric microfluidic pump can be fabricated utilizing mature printed circuit board process with advantages of simple structure and convenient processing. The fabricated printed circuit board process–based microfluidic pump can linearly pump in and pump out fluid with self-injection. Moreover, the flow rate and back pressure can be controlled by changing the peak-to-peak value, frequency, and phase difference of the driving voltages. The instantaneous flow rate has the pulsation property consistent with the drive voltage frequency. The proposed principle and structure are beneficial to integrate the fabricated printed circuit board process–based microfluidic pump with other microfluidic components to realize complicated microfluidic systems on printed circuit board.

Valve-Less Diaphragm Micropump with Electromagnetic Actuation

2013 ◽  
Vol 647 ◽  
pp. 929-934 ◽  
Author(s):  
Yaw Jen Chang ◽  
Yun Wei Chung ◽  
Ting An Chou ◽  
Min Fen Huang
Keyword(s):  
Flow Rate ◽  
Printed Circuit Board ◽  
Lab On A Chip ◽  
Control Circuit ◽  
Fabrication Process ◽  
Circuit Board ◽  
Pdms Layer ◽  
Electromagnetic Actuation ◽  
Casting Technique ◽  
Printed Circuit

In this paper, a micropump with electromagnetic actuation is presented. The micropump mainly consists of coil actuators and a PDMS micropump layer. The microcoil was fabricated using the printed circuit board (PCB) with the conventional PCB treatment and the PDMS layer was formed by casting technique. A control circuit was designed using microcontroller to produce square waves to control coil actuator. Due to the simple fabrication process, the micropump can be incorporated in a disposable PDMS lab-on-a-chip device as a fluid actuation component. However, the coil actuator is reusable. In addition, the control circuit makes the micropump portable. The experiment results show that this proposed micropump is capable of delivering a flow rate of 470 μL/min using one coil actuator.

Principal Component Analysis and Independent Component Analysis-Based Prognostic Health Monitoring of Electronic Assemblies Subjected to Simultaneous Temperature-Vibration Loads

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Pradeep Lall ◽  
Tony Thomas
Keyword(s):  
Principal Component Analysis ◽  
Printed Circuit Board ◽  
Failure Strain ◽  
Principal Component ◽  
Component Analysis ◽  
Circuit Board ◽  
Statistical Techniques ◽  
Time Frequency ◽  
Printed Circuit ◽  
Strain Signal

Abstract This paper discusses methods for estimating different feature vectors from strain signals of an electronic assembly under combined temperature and vibration load. A vibrational load of 14 G acceleration-level with an ambient temperature of 55 °C is selected as the operating conditions for this experiment. Strain signals were measured at different time intervals during the vibration of the printed circuit board, and resistance values of the packages on the printed circuit board are monitored to identify the failure. The frequency response was measured by taking the fast Fourier transform of the signal and quantized by frequency quantization techniques. These techniques were able to identify the increase in the number of higher frequency components in the strain signal before failure with increase vibration time. The time-frequency response was also compared by employing different time–frequency analysis, joint time–frequency analysis, and statistical techniques such as principal component analysis (PCA), and independent component analysis (ICA). Statistical techniques like PCA and ICA were used to identify the different patterns of the original strain and filtered signals. These techniques discretely separated the before and after failure strain signals but were unable to predict the progression of failure in the packages. The instantaneous frequency of the strain signal displayed an interesting behavior, in which the variance of the PCA components of the instantaneous frequency had an increasing trend and reached a maximum value before continuously decreasing and reaching a lower value just before failure, indicating a progression of the before failure strain components.

scholarly journals Microfluidic Mixer with Automated Electrode Switching for Sensing Applications

Chemosensors ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 13 ◽  
Author(s):  
Maria L. Braunger ◽  
Igor Fier ◽  
Varlei Rodrigues ◽  
Paulo E. Arratia ◽  
Antonio Riul
Keyword(s):  
Printed Circuit Board ◽  
Electronic Tongue ◽  
Microfluidic Devices ◽  
Circuit Board ◽  
Physical Interaction ◽  
Layer By Layer ◽  
Passive Mixer ◽  
Microfluidic Mixer ◽  
Sensing Applications ◽  
Food And Beverage

An electronic tongue (e-tongue) is a multisensory system usually applied to complex liquid media that uses computational/statistical tools to group information generated by sensing units into recognition patterns, which allow the identification/distinction of samples. Different types of e-tongues have been previously reported, including microfluidic devices. In this context, the integration of passive mixers inside microchannels is of great interest for the study of suppression/enhancement of sensorial/chemical effects in the pharmaceutical, food, and beverage industries. In this study, we present developments using a stereolithography technique to fabricate microfluidic devices using 3D-printed molds for elastomers exploring the staggered herringbone passive mixer geometry. The fabricated devices (microchannels plus mixer) are then integrated into an e-tongue system composed of four sensing units assembled on a single printed circuit board (PCB). Gold-plated electrodes are designed as an integral part of the PCB electronic circuitry for a highly automated platform by enabling faster analysis and increasing the potential for future use in commercial applications. Following previous work, the e-tongue sensing units are built functionalizing gold electrodes with layer-by-layer (LbL) films. Our results show that the system is capable of (i) covering basic tastes below the human gustative perception and (ii) distinguishing different suppression effects coming from the mixture of both strong and weak electrolytes. This setup allows for triplicate measurements in 12 electrodes, which represents four complete sensing units, by automatically switching all electrodes without any physical interaction with the sensor. The result is a fast and reliable data acquisition system, which comprises a suitable solution for monitoring, sequential measurements, and database formation, being less susceptible to human errors.

Polymer-Coated Single-Walled Carbon Nanotubes for Ethanol and Dichloromethane Discrimination

2013 ◽  
Vol 802 ◽  
pp. 267-272 ◽  
Author(s):  
Worawut Muangrat ◽  
Rungroj Maolanon ◽  
Sirapat Pratontep ◽  
Supanit Porntheeraphat ◽  
Winadda Wongwiriyapan
Keyword(s):  
Carbon Nanotubes ◽  
Pattern Recognition ◽  
Printed Circuit Board ◽  
Gas Sensing ◽  
Principal Component ◽  
Single Walled Carbon Nanotubes ◽  
Sensor Response ◽  
Circuit Board ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

Sensor response and pattern recognition of polymer-coated single-walled carbon nanotubes (SWNTs) were investigated. Printed circuit board (PCB) with Cu/Au interdigitated electrode was used as sensor platform. SWNTs network was firstly formed on PCB by drop-casting. For polymer-coated SWNTs preparation, poly(methyl methacrylate) (PMMA) and thiophene were employed as polymers to coat on SWNTs by spin coating; PMMA/SWNTs and thiophene/SWNTs. Raman spectra showed no obvious structure changes of SWNTs after polymer coating. Next, gas sensing test was conducted. Pristine SWNTs, PMMA/SWNTs and thiophene/SWNTs were exposed to vapors of ethanol and dichloromethane at room temperature. From normalized sensor response results, it was found that pristine SWNTs and PMMA/SWNTs showed the highest response to ethanol and dichloromethane vapors, respectively. In order to discriminate vapors between ethanol and dichloromethane, pattern recognition technique was utilized. Principal component analysis (PCA) results showed that pattern recognition of ethanol and dichloromethane vapors can be discriminated by using pristine SWNTs and polymer-coated SWNTs sensors.

A Research on Drying Performance of Vertical Type Equipment for PCB Wet Process

2012 ◽  
Author(s):  
Jun Young Kim ◽  
Kyung-Min Jang ◽  
Jong-Kuk Yoon ◽  
Kwang-Sun Kim
Keyword(s):  
Flow Rate ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Printed Circuit ◽  
Wet Process ◽  
Washing Process ◽  
Horizontal Type ◽  
Drying Rates ◽  
Two Parameters ◽  
Two Stages

An etching equipment for a printed circuit board (PCB) sprays chemical and DI water through nozzles on the surface of a substrate. The horizontal type equipment moves the substrate between the upper and lower rollers and they cause the damage on the patterns and sagging of the substrate. The flow rate difference between the upper and lower air knives also causes the damage on the substrates when drying them after the end of etching and washing process. To prevent this problem, the forces of the upper and lower air knives should be compensated. The drying rates of the upper and lower sides of the substrate could still be different for the horizontal type because of difficult control of drying flow rates. The vertical type equipment that the rollers don’t contact to the circuits has recently been developed as an alternative to solve the problems. This equipment has advantages that the DI water flows on the both sides of the substrate in the direction of the gravity and the flow rate of the air from the knives can be balanced because of its structural distinction. They lead to the better drying performance without damage on the substrate. The drying process of the substrate consists of two stages which are removing the extra water by wind from the air knives and evaporating the remained moisture by the high temperature of the chamber. In this research, we selected two parameters to optimize the drying capability to the angles of air knives and the temperature in the chamber. We also investigated about the removal capability of the extra drop of water and the remained moisture by using CFD. The design conditions for the process the refore have been founded by analyzing the velocity vector of wind and the time to get the target temperature.

Improve electromagnetic compatibility of electronic products with multivariate parametric design

2017 ◽  
Vol 34 (1) ◽  
pp. 45-55 ◽  
Author(s):  
Chien-Yi Huang ◽  
Ching-Hsiang Chen
Keyword(s):  
Electromagnetic Interference ◽  
Electromagnetic Compatibility ◽  
Printed Circuit Board ◽  
Optimal Parameter ◽  
Principal Component ◽  
Circuit Board ◽  
Design Parameters ◽  
Individual Country ◽  
Content Type ◽  
Noise Factors

Purpose Differing from previous studies trying to solve the electromagnetic compatibility (EMC) issue by addressing single factor, this study aims to combine measures of shielding, filtering and grounding to design parameters with the Taguchi method at the beginning of product design to come up with the optimal parameter combination. Design/methodology/approach EMC-related performance such as radiated emission, conduction interference and electrical fast transient/burst immunity (EFT) are response variables, whereas the printed circuit board and mechanic design-relevant parameters are considered as control factors. The noise factors are peripherals used together with the tablet. Findings The optimal design parameter matrix based on results from the application and integration of multivariate analysis method of principal component grey relation and technique for order preference by similarity to ideal solution suggests 14 grounding screw holes, cooling aperture of casing at diameter of 3 mm and staggered layout and 300O filter located at source of noise. Validation of this matrix shows around 10, 1 and 8 per cent improvement in radiation, conduction interference and EFT immunity. Originality/value The multivariate quality parameters’ design method proposed by this study improves EMC characteristics of products and meets the design specification required by customer, accelerating electronic product research and development process and complying with electromagnetic interference test regulations set forth by individual country.

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