One of the challenges in tissue engineering is to provide adequate supplies oxygen and nutrients cells within engineered construct. Soft-lithographic techniques have allowed generation hydrogel scaffolds containing a network fluidic channels, but at cost complicated often time-consuming manufacturing steps. We report three-dimensional (3D) direct printing technique construct channels. Cells can also be printed on embedded scaffold with this technique. Collagen precursor was subsequently...

We report a contraction-expansion array (CEA) microchannel device that performs label-free high-throughput separation of cancer cells from whole blood at low Reynolds number (Re). The CEA microfluidic utilizes hydrodynamic field effect for cell separation, two kinds inertial effects: (1) lift force and (2) Dean flow, which results in size-based with high throughput. To avoid damages potentially caused by shear stress conventional techniques, the isolates operational Re, maintaining using...

This paper describes a novel microfluidic immunoassay utilizing binding of superparamagnetic nanoparticles to beads and deflection these in magnetic field as the signal for measuring presence analyte. The 50 nm fluorescent 1 µm polystyrene are immobilized with specific antibodies. When target analytes react simultaneously, can be attached onto microbeads by antigen–antibody complex. In poly(dimethylsiloxane) (PDMS) channel, only conjugated consequently move high gradient fields under applied...

We propose a new hydrophoretic method for continuous blood cell separation using microfluidic device composed of slanted obstacles and filtration obstacles. The have larger height gap than the particles in order to focus them sidewall by hydrophoresis. In successive structure, with pore are set between diameters small large particles, which defines critical diameter. Accordingly, smaller criterion freely pass through keep their focused position. contrast, collide against obstacle move into...

This paper presents a novel microfluidic device for dielectrophoretic separation based on trapezoidal electrode array (TEA). In this method, particles with different dielectric properties are separated by the composed of TEA deflection under negative dielectrophoresis (DEP) and poly(dimethylsiloxane) (PDMS) channel sinuous expanded region. Polystyrene microparticles exposed to an electric field generated from in dielectrophoretically focused make all them line up one sidewall. When these...

We report a microfluidic separation and sizing method of microparticles with hydrophoresis--the movement suspended particles under the influence microstructure-induced pressure field. By exploiting slanted obstacles in microchannel, we can generate lateral gradient so that be deflected arranged along flows induced by gradient. Using such movements particles, completely separated polystyrene microbeads 9 12 microm diameters. Also, discriminated diameter differences approximately 7.3%....

We present a direct cell printing technique to pattern neural cells in three-dimensional (3D) multilayered collagen gel. A layer of precursor was printed provide scaffold for the cells, and rat embryonic neurons astrocytes were subsequently on layer. solution sodium bicarbonate applied containing as nebulized aerosols, which allowed gelation collagen. This process repeated layer-by-layer construct 3D cell-hydrogel composites. Upon characterizing relationship between resolutions growth...

This paper describes a new label-free cell separation method using magnetic repulsion force resulting from the susceptibility difference between cells and paramagnetic buffer solution in microchannel. The forces acting on different-sized is enhanced by adjusting of surrounding medium, which depends concentration salts, such as biocompatible gadolinium diethylenetriamine pentaacetic acid (Gd–DTPA), dissolved therein. As proof-of-concept demonstration, Gd–DTPA solutions at concentrations 0–80...

This paper presents a pressed paper-based dipstick that enables detection of foodborne pathogens with multistep reactions by exploiting the delayed fluid flow and channel partition formation on nitrocellulose (NC) membrane. Fluid behaviors are easily modified controlling amount pressure position region NC Detection is optimized rate time based Darcy's law. All reagents required for assay dried membrane they sequentially rehydrated at prepartitioned regions when device dipped into sample...

We report a contraction–expansion array (CEA) microchannel that allows three-dimensional hydrodynamic focusing with single sheath flow in single-layer device. The CEA exploits centrifugal forces acting on fluids travelling along the contraction and expansion regions of microchannel. Around an entrance region, induce secondary field where two counter-rotating vortices enable to envelop sample three dimensions. herein describe underlying principle design demonstrate complete sheathing fluid...

We have proposed a novel mobile healthcare platform, combining pocket-sized colorimetric reader (13.5 × 6.5 2.5 cm(3)) and commercially available 10-parameter urinalysis paper strips (glucose, protein, glucose, bilirubin, urobilinogen, ketones, nitrite, pH, specific gravity, erythrocytes, leukocytes), capable of sending data with smart phone. The includes multi-detection module, which consists three-chromatic light-emitting diodes, silicon photodiodes poly(methylmethacrylate) (PMMA) optical...

This paper presents a microfluidic device for sheathless focusing of microbeads and blood cells based on hydrophoretic platform comprising V-shaped obstacle array (VOA). The VOA generates lateral pressure gradients that induce helical recirculations. Following the flow particles passing through are focused in center channel. In device, pattern can be modulated by varying gap height VOA. To achieve complete within 4.4% coefficient variation, relative size differences between particle were 3 4...

Cell cycle studies for examining regulatory mechanisms and progression invariably require synchronization of cell cultures at a specific phase the cycle. Current implementations to produce synchronous populations, however, tend perturb normal cellular metabolism typically complex, time-consuming preparations. Thus, it is challenging development simple, noninvasive, effective means synchronization. We demonstrate use hydrophoretic size separation sort cells in target phases entirely based on...

This Letter describes a quantitative phase microscopy for microfluidic devices using simple self-referencing interferometry. Compared with the gross dimensions of device, microchannel occupies only small area device. Hence, reference field can be generated by inverting relative position specimen and background. Our system is realized an extended depth-of-field optics in form Michelson interferometry, which allows measurement increased without moving objective lens or specimen. Furthermore,...

Continuous inertial blood plasma separation is demonstrated in a contraction–expansion array microchannel with low aspect ratio (AR). The cutoff value of the particle size can be controlled by modulation force balance between lift and Dean drag forces. achieved changing channel AR at contraction region, which causes change magnitudes forces on particles. presented separator provides level yield throughput 62.2% 1.2 ml/h(∼1.0×108 cells/min), respectively.

Loss of contractility and acquisition an epithelial phenotype vascular smooth muscle cells (VSMCs) are key events in proliferative pathologies such as atherosclerosis post-angioplastic restenosis. There is no proper cell culture system allowing differentiation VSMCs so that it difficult to delineate the molecular mechanism responsible for vasculopathy. We investigated whether a micropatterned substrate could restore contractile vitro. To induce maintain differentiated VSMC vitro, we...