Fabrication Techniques for Production of Thermoplastic-Based Microfluidics Devices

2016 ◽  
Vol 04 (03) ◽  
pp. 1640016 ◽  
Author(s):  
Zhenfeng Wang
Keyword(s):  
Point Of Care ◽  
Emerging Market ◽  
Science Research ◽  
Polymer Materials ◽  
Microfluidic Chips ◽  
Face Lift ◽  
Point Of Care Diagnostics ◽  
Wide Range ◽  
The Face ◽  
Micro Tooling

Microfluidics is a multidisciplinary technology which enables the face-lift crossing a wide range of applications such as life science research, point-of-care diagnostics and personal medicine. Polymer materials, especially thermoplastics, are dominating this emerging market due to the low material cost and the ease of mass production. This paper reviews the major fabrication technologies for making polymer, especially thermoplastic microfluidic chips, such as micro tooling, injection molding, bonding and surface treatment. The paper also summarizes the key challenges in fulfilling the needs of next generation microfluidic products.

scholarly journals Microfluidics-Based Plasmonic Biosensing System Based on Patterned Plasmonic Nanostructure Arrays

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 826
Author(s):  
Yanting Liu ◽  
Xuming Zhang
Keyword(s):  
Plasmon Resonance ◽  
Point Of Care ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Microfluidic Chips ◽  
Label Free ◽  
Plasmonic Nanostructure ◽  
Point Of Care Diagnostics ◽  
Surface Enhanced Raman ◽  
Nanostructure Arrays

This review aims to summarize the recent advances and progress of plasmonic biosensors based on patterned plasmonic nanostructure arrays that are integrated with microfluidic chips for various biomedical detection applications. The plasmonic biosensors have made rapid progress in miniaturization sensors with greatly enhanced performance through the continuous advances in plasmon resonance techniques such as surface plasmon resonance (SPR) and localized SPR (LSPR)-based refractive index sensing, SPR imaging (SPRi), and surface-enhanced Raman scattering (SERS). Meanwhile, microfluidic integration promotes multiplexing opportunities for the plasmonic biosensors in the simultaneous detection of multiple analytes. Particularly, different types of microfluidic-integrated plasmonic biosensor systems based on versatile patterned plasmonic nanostructured arrays were reviewed comprehensively, including their methods and relevant typical works. The microfluidics-based plasmonic biosensors provide a high-throughput platform for the biochemical molecular analysis with the advantages such as ultra-high sensitivity, label-free, and real time performance; thus, they continue to benefit the existing and emerging applications of biomedical studies, chemical analyses, and point-of-care diagnostics.

scholarly journals Self-Powered Portable Electronic Reader for Point-of-Care Amperometric Measurements

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3715 ◽  
Author(s):  
Yaiza Montes-Cebrián ◽  
Albert Álvarez-Carulla ◽  
Jordi Colomer-Farrarons ◽  
Manel Puig-Vidal ◽  
Pere Ll. Miribel-Català
Keyword(s):  
Low Power ◽  
Point Of Care ◽  
Power Source ◽  
Laboratory Equipment ◽  
Fuel Concentration ◽  
Point Of Care Diagnostics ◽  
External Power Source ◽  
Wide Range ◽  
External Power ◽  
Self Powered

In this work, we present a self-powered electronic reader (e-reader) for point-of-care diagnostics based on the use of a fuel cell (FC) which works as a power source and as a sensor. The self-powered e-reader extracts the energy from the FC to supply the electronic components concomitantly, while performing the detection of the fuel concentration. The designed electronics rely on straightforward standards for low power consumption, resulting in a robust and low power device without needing an external power source. Besides, the custom electronic instrumentation platform can process and display fuel concentration without requiring any type of laboratory equipment. In this study, we present the electronics system in detail and describe all modules that make up the system. Furthermore, we validate the device’s operation with different emulated FCs and sensors presented in the literature. The e-reader can be adjusted to numerous current ranges up to 3 mA, with a 13 nA resolution and an uncertainty of 1.8%. Besides, it only consumes 900 µW in the low power mode of operation, and it can operate with a minimum voltage of 330 mV. This concept can be extended to a wide range of fields, from biomedical to environmental applications.

scholarly journals Accelerated RNA detection using tandem CRISPR nucleases

2021 ◽  
Author(s):  
Tina Y. Liu ◽  
Gavin J. Knott ◽  
Dylan C.J. Smock ◽  
John J. Desmarais ◽  
Sungmin Son ◽  
...  
Keyword(s):  
Imaging System ◽  
Point Of Care ◽  
Reaction Times ◽  
Microfluidic Chips ◽  
Rna Detection ◽  
Fluorescent Reporter ◽  
Robust Detection ◽  
Site Analysis ◽  
Wide Range ◽  
Direct Amplification

Direct, amplification-free detection of RNA has the potential to transform molecular diagnostics by enabling simple on-site analysis of human or environmental samples. CRISPR-Cas nucleases offer programmable RNA-guided recognition of RNA that triggers cleavage and release of a fluorescent reporter molecule1,2, but long reaction times hamper sensitivity and speed when applied to point-of-care testing. Here we show that unrelated CRISPR nucleases can be deployed in tandem to provide both direct RNA sensing and rapid signal generation, thus enabling robust detection of ~30 RNA copies/microliter in 20 minutes. Combining RNA-guided Cas13 and Csm6 with a chemically stabilized activator creates a one-step assay that detected SARS-CoV-2 RNA from nasopharyngeal samples with PCR-derived Ct values up to 29 in microfluidic chips, using a compact imaging system. This Fast Integrated Nuclease Detection In Tandem (FIND-IT) approach enables direct RNA detection in a format amenable to point-of-care infection diagnosis, as well as to a wide range of other diagnostic or research applications.

scholarly journals Nanozymes in Point-of-Care Diagnosis: An Emerging Futuristic Approach for Biosensing

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Bhaskar Das ◽  
Javier Lou Franco ◽  
Natasha Logan ◽  
Paramasivan Balasubramanian ◽  
Moon Il Kim ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Point Of Care ◽  
Low Cost ◽  
Metal Organic Framework ◽  
World Health ◽  
Point Of Care Diagnostics ◽  
Enzyme Mimicking ◽  
Wide Range ◽  
Metal Metal

AbstractNanomaterial-based artificial enzymes (or nanozymes) have attracted great attention in the past few years owing to their capability not only to mimic functionality but also to overcome the inherent drawbacks of the natural enzymes. Numerous advantages of nanozymes such as diverse enzyme-mimicking activities, low cost, high stability, robustness, unique surface chemistry, and ease of surface tunability and biocompatibility have allowed their integration in a wide range of biosensing applications. Several metal, metal oxide, metal–organic framework-based nanozymes have been exploited for the development of biosensing systems, which present the potential for point-of-care analysis. To highlight recent progress in the field, in this review, more than 260 research articles are discussed systematically with suitable recent examples, elucidating the role of nanozymes to reinforce, miniaturize, and improve the performance of point-of-care diagnostics addressing the ASSURED (affordable, sensitive, specific, user-friendly, rapid and robust, equipment-free and deliverable to the end user) criteria formulated by World Health Organization. The review reveals that many biosensing strategies such as electrochemical, colorimetric, fluorescent, and immunological sensors required to achieve the ASSURED standards can be implemented by using enzyme-mimicking activities of nanomaterials as signal producing components. However, basic system functionality is still lacking. Since the enzyme-mimicking properties of the nanomaterials are dictated by their size, shape, composition, surface charge, surface chemistry as well as external parameters such as pH or temperature, these factors play a crucial role in the design and function of nanozyme-based point-of-care diagnostics. Therefore, it requires a deliberate exertion to integrate various parameters for truly ASSURED solutions to be realized. This review also discusses possible limitations and research gaps to provide readers a brief scenario of the emerging role of nanozymes in state-of-the-art POC diagnosis system development for futuristic biosensing applications.

scholarly journals Thin Flexible Lab-on-a-Film for Impedimetric Sensing in Biomedical Applications

2021 ◽  
Author(s):  
Amina Farooq ◽  
Fezan Hayat ◽  
Sobia Zafar ◽  
Nauman Zafar Butt
Keyword(s):  
Bond Strength ◽  
Signal To Noise Ratio ◽  
Point Of Care ◽  
Flexible Substrate ◽  
Pulse Amplitude ◽  
Medical Diagnostics ◽  
Design Guidelines ◽  
Covalent Crosslinking ◽  
Point Of Care Diagnostics ◽  
Wide Range

Abstract Microfluidic cytometers based on coulter principle have recently shown a great potential for point of care biosensors for medical diagnostics. Here, we explore the design of an impedimetric microfluidic cytometer on flexible substrate. Two coplanar microfluidic geometries are compared to highlight the sensitivity of the device to the microelectrode positions relative to the detection volume. We show that the microelectrodes surface area and the geometry of the sensing volume for the cells strongly influence the output response of the sensor. Reducing the sensing volume decreases the pulse width but increases the overall pulse amplitude with an enhanced signal-to-noise ratio (~max. SNR=38.78dB). For the proposed design, the SNR was adequate to enable good detection and differentiation of 10 µm diameter polystyrene beads and leukemia cells (~6-21 µm). Also, a systematic approach for irreversible & strong bond strength between the thin flexible surfaces that make up the biochip is explored in this work. We observed the changes in surface wettability due to various methods of surface treatment can be a valuable metric for determining bond strength. We observed permanent bonding between microelectrode defined polypropylene surface and microchannel carved PDMS due to polar/silanol groups formed by plasma treatment and consequent covalent crosslinking by amine groups. These experimental insights provide valuable design guidelines for enhancing the sensitivity of coulter based flexible lab-on-a-chip devices which have a wide range of applications in point of care diagnostics.

scholarly journals Machine Learning-Based HIV Risk Estimation Using Incidence Rate Ratios

2021 ◽  
Vol 3 ◽  
Author(s):  
Oliver Haas ◽  
Andreas Maier ◽  
Eva Rothgang
Keyword(s):  
Machine Learning ◽  
Incidence Rate ◽  
Clinical Data ◽  
Hiv Risk ◽  
Point Of Care ◽  
Risk Estimation ◽  
Expert Opinions ◽  
Point Of Care Diagnostics ◽  
Wide Range ◽  
Hiv Aids

HIV/AIDS is an ongoing global pandemic, with an estimated 39 million infected worldwide. Early detection is anticipated to help improve outcomes and prevent further infections. Point-of-care diagnostics make HIV/AIDS diagnoses available both earlier and to a broader population. Wide-spread and automated HIV risk estimation can offer objective guidance. This supports providers in making an informed decision when considering patients with high HIV risk for HIV testing or pre-exposure prophylaxis (PrEP). We propose a novel machine learning method that allows providers to use the data from a patient's previous stays at the clinic to estimate their HIV risk. All features available in the clinical data are considered, making the set of features objective and independent of expert opinions. The proposed method builds on association rules that are derived from the data. The incidence rate ratio (IRR) is determined for each rule. Given a new patient, the mean IRR of all applicable rules is used to estimate their HIV risk. The method was tested and validated on the publicly available clinical database MIMIC-IV, which consists of around 525,000 hospital stays that included a stay at the intensive care unit or emergency department. We evaluated the method using the area under the receiver operating characteristic curve (AUC). The best performance with an AUC of 0.88 was achieved with a model consisting of 53 rules. A threshold value of 0.66 leads to a sensitivity of 98% and a specificity of 53%. The rules were grouped into drug abuse, psychological illnesses (e.g., PTSD), previously known associations (e.g., pulmonary diseases), and new associations (e.g., certain diagnostic procedures). In conclusion, we propose a novel HIV risk estimation method that builds on existing clinical data. It incorporates a wide range of features, leading to a model that is independent of expert opinions. It supports providers in making informed decisions in the point-of-care diagnostics process by estimating a patient's HIV risk.

Classical Greek Oligarchy

2017 ◽  
Author(s):  
Matthew Simonton
Keyword(s):  
Public Space ◽  
Political Institutions ◽  
Social Science Research ◽  
Science Research ◽  
Power Sharing ◽  
Majority Population ◽  
New Development ◽  
The Face ◽  
Changes Over Time ◽  
Client Relations

This book thoroughly reassesses an important but neglected form of government in ancient Greece, the “rule of the few.” The book challenges scholarly orthodoxy by showing that oligarchy was not the default mode of politics from time immemorial, but instead emerged alongside, and in reaction to, democracy. It establishes how oligarchies maintained power in the face of potential citizen resistance. It argues that oligarchs designed distinctive political institutions—such as intra-oligarchic power sharing, targeted repression, and rewards for informants—to prevent collective action among the majority population while sustaining cooperation within their own ranks. To clarify the workings of oligarchic institutions, the book draws on recent social science research on authoritarianism. Like modern authoritarian regimes, ancient Greek oligarchies had to balance coercion with co-optation in order to keep their subjects disorganized and powerless. The book investigates topics such as control of public space, the manipulation of information, and the establishment of patron–client relations, frequently citing parallels with contemporary nondemocratic regimes. It also traces changes over time in antiquity, revealing the processes through which oligarchy lost the ideological battle with democracy for legitimacy. This book represents a major new development in the study of ancient politics. It fills a longstanding gap in our knowledge of nondemocratic government while greatly improving our understanding of forms of power that continue to affect us today.

ESRC Review

2020 ◽  
pp. 657-698
Author(s):  
Simeon J. Yates ◽  
Jordana Blejmar
Keyword(s):  
Social Research ◽  
Social Science Research ◽  
Research Work ◽  
Science Research ◽  
Wide Range ◽  
The Us ◽  
Levels Of Automation ◽  
The Uk ◽  
Technological World ◽  
Ways Of Being

Two workshops were part of the final steps in the Economic and Social Research Council (ESRC) commissioned Ways of Being in a Digital Age project that is the basis for this Handbook. The ESRC project team coordinated one with the UK Defence Science and Technology Laboratory (ESRC-DSTL) Workshop, “The automation of future roles”; and one with the US National Science Foundation (ESRC-NSF) Workshop, “Changing work, changing lives in the new technological world.” Both workshops sought to explore the key future social science research questions arising for ever greater levels of automation, use of artificial intelligence, and the augmentation of human activity. Participants represented a wide range of disciplinary, professional, government, and nonprofit expertise. This chapter summarizes the separate and then integrated results. First, it summarizes the central social and economic context, the method and project context, and some basic definitional issues. It then identifies 11 priority areas needing further research work that emerged from the intense interactions, discussions, debates, clustering analyses, and integration activities during and after the two workshops. Throughout, it summarizes how subcategories of issues within each cluster relate to central issues (e.g., from users to global to methods) and levels of impacts (from wider social to community and organizational to individual experiences and understandings). Subsections briefly describe each of these 11 areas and their cross-cutting issues and levels. Finally, it provides a detailed Appendix of all the areas, subareas, and their specific questions.

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