Microfluidics or lab-on-a-chip (LOC) is an important technology suitable for numerous applications from drug delivery to tissue engineering. Microfluidic devices for biomedical applications discusses ...the fundamentals of microfluidics and explores in detail a wide range of medical applications.The first part of the book reviews the fundamentals of microfluidic technologies for biomedical applications with chapters focussing on the materials and methods for microfabrication, microfluidic actuation mechanisms and digital microfluidic technologies. Chapters in part two examine applications in drug discovery and controlled-delivery including micro needles. Part three considers applications of microfluidic devices in cellular analysis and manipulation, tissue engineering and their role in developing tissue scaffolds and stem cell engineering. The final part of the book covers the applications of microfluidic devices in diagnostic sensing, including genetic analysis, low-cost bioassays, viral detection, and radio chemical synthesis.Microfluidic devices for biomedical applications is an essential reference for medical device manufacturers, scientists and researchers concerned with microfluidics in the field of biomedical applications and life-science industries. * Discusses the fundamentals of microfluidics or lab-on-a-chip (LOC) and explores in detail a wide range of medical applications * Considers materials and methods for microfabrication, microfluidic actuation mechanisms and digital microfluidic technologies * Considers applications of microfluidic devices in cellular analysis and manipulation, tissue engineering and their role in developing tissue scaffolds and stem cell engineering
We report on a wearable tear bioelectronic platform, integrating a microfluidic electrochemical detector into an eyeglasses nose-bridge pad, for non-invasive monitoring of key tear biomarkers. The ...alcohol-oxidase (AOx) biosensing fluidic system allowed real-time tear collection and direct alcohol measurements in stimulated tears, leading to the first wearable platform for tear alcohol monitoring. Placed outside the eye region this fully wearable tear-sensing platform addresses drawbacks of sensor systems involving direct contact with the eye as the contact lenses platform. Integrating the wireless electronic circuitry into the eyeglasses frame thus yielded a fully portable, convenient-to-use fashionable sensing device. The tear alcohol sensing concept was demonstrated for monitoring of alcohol intake in human subjects over multiple drinking courses, displaying good correlation to parallel BAC measurements. We also demonstrate for the first time the ability to monitor tear glucose outside the eye and the utility of wearable devices for monitoring vitamin nutrients in connection to enzymatic flow detector and rapid voltammetric scanning, respectively. These developments pave the way to build an effective eyeglasses system capable of chemical tear analysis.
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•Wearable fluidic tears biosensor and wireless circuitry integrated into eyeglasses for non-invasive biomarker monitoring.•Wearable tear sensing platform placed outside the eye region mitigates drawbacks of systems requiring direct eye contact.•Real-time collection and direct measurements of stimulated tears allow the first wearable tear alcohol monitoring platform.
Long-term storage and controlled release of multiple components while avoiding cross-contamination have potentially important applications for pharmaceuticals and cosmetics. Polymersomes are very ...promising delivery vehicles but cannot be used to encapsulate multiple independent components and release them in a controlled manner. Here, we report a microfluidic approach to produce multiple polymersomes, or polymersomes-in-polymersome by design, enabling encapsulation and programmed release of multiple components. Monodisperse polymersomes are prepared from templates of double-emulsion drops, which in turn are injected as the innermost phase to form the second level of double-emulsion drops, producing double polymersomes. Using the same strategy, higher-order polymersomes are also prepared. In addition, incorporation of hydrophobic homopolymer into the different bilayers of the multiple polymersomes enables controlled and sequential dissociation of the different bilayer membranes in a programmed fashion. The high encapsulation efficiency of this microfluidic approach, as well as its programmability and the biocompatibility of the materials used to form the polymersomes, will provide new opportunities for practical delivery systems of multiple components.
Portable electronic devices and wireless communication systems enable a broad range of applications such as environmental and food safety monitoring, personalized medicine and healthcare management. ...Particularly, hybrid smartphone and microfluidic devices provide an integrated solution for the new generation of mobile sensing applications. Such mobile sensing based on microfluidic devices (broadly defined) and smartphones (MS(2)) offers a mobile laboratory for performing a wide range of bio-chemical detection and analysis functions such as water and food quality analysis, routine health tests and disease diagnosis. MS(2) offers significant advantages over traditional platforms in terms of test speed and control, low cost, mobility, ease-of-operation and data management. These improvements put MS(2) in a promising position in the fields of interdisciplinary basic and applied research. In particular, MS(2) enables applications to remote in-field testing, homecare, and healthcare in low-resource areas. The marriage of smartphones and microfluidic devices offers a powerful on-chip operating platform to enable various bio-chemical tests, remote sensing, data analysis and management in a mobile fashion. The implications of such integration are beyond telecommunication and microfluidic-related research and technology development. In this review, we will first provide the general background of microfluidic-based sensing, smartphone-based sensing, and their integration. Then, we will focus on several key application areas of MS(2) by systematically reviewing the important literature in each area. We will conclude by discussing our perspectives on the opportunities, issues and future directions of this emerging novel field.
Paper-based biosensors are promising for low-cost diagnostics. However, its widespread use has been hampered due to a lack of sensitive detection methods that can be easily implemented on paper ...substrates. On the other hand, single-walled carbon nanotubes (SWNTs) -based chemiresistive biosensors are gaining popularity as label-free, highly sensitive biosensors. However, traditional SWNT-based chemiresistors need to be more affordable for use in resource-limited settings. In this study, we report fabrication, optimization and analytical characterization of a chemiresistive biosensor on paper for label-free immunosensing. We synthesized a water-based ink using pyrene carboxylic acid (PCA) through non-covalent π-π stacking interaction between PCA and SWNTs. The PCA/SWNTs ink concentration can reach ~4 mg mL−1 and was stable at room temperature for one month. We introduced a combination of wax printing and vacuum filtration to fabricate the hydrophilic channels and the well-defined PCA/SWNTs ink deposition on paper in a facile manner requiring no additional masks or stencils. Specific antibodies were then functionalized on the PCA/SWNTs. Quantitative and selective detection of human serum albumin (HSA) is demonstrated with a limit of detection (LOD) of 1 pM. This low LOD is attributed to the porous structure of the paper surface, which can accommodate more SWNTs. Furthermore, the hydroxyl group-containing cellulose fibers help connect the SWNTs into an electrical network. The paper-based chemiresistive biosensor proposed here is easy to fabricate, and designed for rapid, sensitive and selective detection of HSA. This work provides a potential platform for automated, disposable paper-based biosensors with multiplexed detection capability and microfluidic controls.
•Low-cost, label-free SWNTs-based chemiresistive biosensor on paper is reported.•Simple, fast, stencil-free wax printing and vacuum filtration used for fabrication.•High concentration, stable, water-based SWNTs ink defines sensing channel.•Bioreceptor immobilized covalently on SWNTs by zero-length crosslinking chemistry.•Highly sensitive, selective, label-free human serum albumin detection demonstrated.
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