Microfluidics for Biological Applications provides researchers and scientists in the biotechnology, pharmaceutical, and life science industries with an introduction to the basics of microfluidics and also discusses how to link these technologies to various biological applications at the industrial and academic level. Readers will gain insight into a wide variety of biological applications for microfluidics. The material presented here is divided into four parts, Part I gives perspective on the history and development of microfluidic technologies, Part II presents overviews on how microfluidic systems have been used to study and manipulate specific classes of components, Part III focuses on specific biological applications of microfluidics: biodefense, diagnostics, high throughput screening, and tissue engineering and finally Part IV concludes with a discussion of emerging trends in the microfluidics field and the current challenges to the growth and continuing success of the field.

Microfluidics in Cell Biology Part A: Volume 146, the latest release in the Methods in Cell Biology series, continues the legacy of this premier serial with quality chapters authored by leaders in the field. Unique to this updated volume are sections on Cell monolayers/spheroids, Collective migration in microtubes, Leukocyte adhesion dynamics on endothelial monolayers under flow, Constrained spheroid for perfusion culture, Cells in droplet arrays, Heart on chips, Kidney on chips, Liver on chips and hepatic immune responses, Gut on chips, 3D microvascular model-based lymphoma model, Blood brain barrier on chips, Multi-organ-on-a-chip for pharmacokinetic analysis, Cancer immunotherapy on chips, and more. - Contains contributions from experts in the field from across the globe - Covers a wide array of topics on both mitosis and meiosis - Includes relevant, analysis based topics

Polymeric microparticles have a wide variety of uses, ranging from traditional applications in paints and coatings, to specialized applications in medical therapeutics and diagnostics. For biological applications - including drug delivery, analytical assays, and tissue engineering - it is important to tailor the interactions between the microparticles and their external environment. To do this, it is necessary to precisely control the physical and chemical properties of the engineered microparticles. Recently, it has become apparent that in addition to particle chemistry, the physical properties of a particle - for example, size, shape, internal structure, and mechanical deformability - play an important role in determining particle behaviour in biological environments. However, it remains largely unknown exactly how these various physical properties influence particle behaviour and function, and how these properties should be exploited for different applications. This thesis focuses on the development and characterization of polymeric hydrogel microparticles with well-controlled physical and chemical properties, and shows several applications of these custom microparticles. In particular, we explore particle motifs inspired by biological entities, designing particles with different shapes, internal structure, and mechanical deformability, functionalized with proteins and nucleic acids. We employ microfluidic tools for synthesis and characterization of these hydrogel microparticles, and also investigate the interaction of functionalized particles with nucleic acids and cells, in the context of biomolecule detection and specific cell capture, respectively. Based on the microfluidic particle synthesis technique, stop flow lithography, we fabricate custom particles - including non-spherical 3D capsules and 2D extruded cylindrical rings with systematically varied internal architecture. We design microfluidic channels to study the flow and deformation of these particles, investigating the effects of internal structure, size, and stiffness on passage through microfluidic constrictions. We expand on this work, designing a microfluidic platform to specifically position particles in hydrodynamic traps, based on particle physical properties. This platform enables subsequent encapsulation of immobilized particles in monodisperse, isolated aqueous droplets. We demonstrate the platform's utility with chemically functionalized microparticles enabling sensitive, multiplexed microRNA detection. To further explore the interactions of functionalized microparticles with biological systems, we study how antibody-functionalized microparticles of varying shape can capture specific cells for future diagnostic applications.

Microfluidics for Biological Applications provides researchers and scientists in the biotechnology, pharmaceutical, and life science industries with an introduction to the basics of microfluidics and also discusses how to link these technologies to various biological applications at the industrial and academic level. Readers will gain insight into a wide variety of biological applications for microfluidics. The material presented here is divided into four parts, Part I gives perspective on the history and development of microfluidic technologies, Part II presents overviews on how microfluidic systems have been used to study and manipulate specific classes of components, Part III focuses on specific biological applications of microfluidics: biodefense, diagnostics, high throughput screening, and tissue engineering and finally Part IV concludes with a discussion of emerging trends in the microfluidics field and the current challenges to the growth and continuing success of the field.

While the rapidly-growing microfluidics technology has already permeated through many aspects of the molecular and biological sciences and enabled a wide variety of low-cost and point-of-care biomedical applications, deformable microfluidics, in which microchannel possesses at least one flexible sidewall, may offer some unique advantages. The recyclability of such platforms is improved and their lifetime is extended thanks to the minimal channel clogging. The difficulties associated with the deviation of device performance from an optimal point can also be alleviated to some extent by tuning the device. Furthermore, deformable microfluidic devices may be adjusted to have more than one optimal operating points. For example, a single deformable microfluidic filter is capable of isolating target cells with multiple sizes or deformability levels as opposed to a rigid counterpart that has only one cutoff size for filtering. In typical deformable microfluidic settings, the deformable part of microchannel is actuated via external pneumatic sources, making it difficult to fabricate and operate such devices. The main objectives of this work are 1) to develop a new class of deformable microfluidics without the need to pneumatic actuation, and 2) to develop analytical tools for studying flows of Newtonian fluids in deformable microchannels. Pressure distribution within a deformable microchannel dictates the membrane deformation, while the membrane deformation governs the hydrodynamic resistance and consequently the pressure distribution within the channel. Deformable microfluidics, therefore, gives rise to a coupled fluid-solid interaction problem. Compressibility of the working fluid and variations of the channel's width are two other factors that can potentially make the problem even more complicated. In this work, an analytical model, with no fitting parameters, is derived simultaneously taking microchannel deformability, fluid compressibility, and microchannel's width profile into account, which makes it a universal tool for studying low-Reynolds-number flows of Newtonian liquids and gases in microscale. A new technique is also developed for fabrication of shallow (few microns in height) rigid/flexible microchannels with either small (tens of microns) or large (several millimeters) width. We show theoretically and experimentally that structural-fluid characteristics are solely dictated by dimensionless fluid compressibility and a lumped dimensionless parameter, called flexibility parameter. A master curve is obtained for fluid flow through any arbitrary shallow and long deformable microchannel presenting the dimensionless flow rate as functions of flexibility parameter and dimensionless fluid compressibility. The experimental and analytical investigations reveal various distinct fluid-structural characteristic behaviors under different fluid compressibility and flexibility parameter regimes. We have also demonstrated that passive rectification of compressible and incompressible flows of Newtonian fluids (liquids and gases) under the Stokes flow regime (Re “ 1) is feasible by introducing the non-linear and direction-dependent terms to the otherwise linear equations of motion. Finally, a new class of deformable microfluidics is developed for passively-tunable particle trapping and isolation without the need to the pneumatic actuation. Filtration, isolation, and retrieval of particles are successfully demonstrated.