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Kimberly Plevniak, Matthew Campbell, Timothy Myers, Abby Hodges, Mei He
Clinical diagnosis requiring central facilities and site visits can be burdensome for patients in resource-limited or rural areas. Therefore, development of a low-cost test that utilizes smartphone data collection and transmission would beneficially enable disease self-management and point-of-care (POC) diagnosis. In this paper, we introduce a low-cost iPOC(3D) diagnostic strategy which integrates 3D design and printing of microfluidic POC device with smartphone-based disease diagnosis in one process as a stand-alone system, offering strong adaptability for establishing diagnostic capacity in resource-limited areas and low-income countries...
September 2016: Biomicrofluidics
Pin-Chuan Chen, Chih-Chun Chen, Kung-Chia Young
In this study, we developed a fully thermoplastic microfiltration chip for the separation of blood plasma from human blood. Spiral microchannels were manufactured on a PMMA substrate using a micromilling machine, and a commercial polycarbonate membrane was bonded between two thermoplastic substrates. To achieve an excellent bonding between the commercial membrane and the thermoplastic substrates, we used a two-step injection and curing procedure of UV adhesive into a ring-shaped structure around the microchannel to efficiently prevent leakage during blood filtration...
September 2016: Biomicrofluidics
Jingjing Zhao, Zheng You
This work introduces three rectangular quasi-flat-top spots, which are provided by binary optical elements (BOEs) and utilized for the illumination in a microflow cytometer. The three spots contain, respectively, one, two, and three rectangles (R1, R2, and R3). To test the performance of this mechanism, a microflow cytometer is established by integrating the BOEs and a three-dimensional hydrodynamic focusing chip. Through the experiments of detecting fluorescence microbeads, the three spots present good fluorescence coefficients of variation in comparison with those derived from commercial instruments...
September 2016: Biomicrofluidics
Zongjie Wang, Roya Samanipour, Mohamed Gamaleldin, Kabilan Sakthivel, Keekyoung Kim
Microdroplets have been widely used in various biomedical applications. During droplet generation, parameters are manually adjusted to achieve the desired size of droplets. This process is tedious and time-consuming. In this paper, we present a fully automated system for controlling the size of droplets to optimize droplet generation parameters in a microfluidic flow-focusing device. The developed system employed a novel image processing program to measure the diameter of droplets from recorded video clips and correspondingly adjust the flow rates of syringe pumps to obtain the required diameter of droplets...
September 2016: Biomicrofluidics
Steven A Roberts, Kyle A DiVito, Frances S Ligler, André A Adams, Michael A Daniele
Integrating a perfusable microvasculature system in vitro is a substantial challenge for "on-chip" tissue models. We have developed an inclusive on-chip platform that is capable of maintaining laminar flow through porous biosynthetic microvessels. The biomimetic microfluidic device is able to deliver and generate a steady perfusion of media containing small-molecule nutrients, drugs, and gases in three-dimensional cell cultures, while replicating flow-induced mechanical stimuli. Here, we characterize the diffusion of small molecules from the perfusate, across the microvessel wall, and into the matrix of a 3D cell culture...
September 2016: Biomicrofluidics
M Sneha Maria, P E Rakesh, T S Chandra, A K Sen
We report capillary flow of blood in a microchannel with differential wetting for the separation of a plasma from sample blood and subsequent on-chip detection of glucose present in a plasma. A rectangular polydimethylsiloxane microchannel with hydrophilic walls (on three sides) achieved by using oxygen plasma exposure enables capillary flow of blood introduced at the device inlet through the microchannel. A hydrophobic region (on all four sides) in the microchannel impedes the flow of sample blood, and the accumulated blood cells at the region form a filter to facilitate the separation of a plasma...
September 2016: Biomicrofluidics
Katherine N Clayton, Janelle W Salameh, Steven T Wereley, Tamara L Kinzer-Ursem
As the field of colloidal science continues to expand, tools for rapid and accurate physiochemical characterization of colloidal particles will become increasingly important. Here, we present Particle Scattering Diffusometry (PSD), a method that utilizes dark field microscopy and the principles of particle image velocimetry to measure the diffusivity of particles undergoing Brownian motion. PSD measures the diffusion coefficient of particles as small as 30 nm in diameter and is used to characterize changes in particle size and distribution as a function of small, label-free, surface modifications of particles...
September 2016: Biomicrofluidics
Kar M Ang, Leslie Y Yeo, Yew M Hung, Ming K Tan
The ability to drive microcentrifugation for efficient micromixing and particle concentration and separation on a microfluidic platform is critical for a wide range of lab-on-a-chip applications. In this work, we investigate the use of amplitude modulation to enhance the efficiency of the microcentrifugal recirculation flows in surface acoustic wave microfluidic systems, thus concomitantly reducing the power consumption in these devices for a given performance requirement-a crucial step in the development of miniaturized, integrated circuits for true portable functionality...
September 2016: Biomicrofluidics
Lap Man Lee, Jin Woo Lee, Danielle Chase, Daniel Gebrezgiabhier, Allen P Liu
Various micro-engineered tools or platforms have been developed recently for cell mechanics studies based on acoustic, magnetic, and optical actuations. Compared with other techniques for single cell manipulations, microfluidics has the advantages with simple working principles and device implementations. In this work, we develop a multi-layer microfluidic pipette aspiration device integrated with pneumatically actuated microfluidic control valves. This configuration enables decoupling of cell trapping and aspiration, and hence causes less mechanical perturbation on trapped single cells before aspiration...
September 2016: Biomicrofluidics
Di Li, Xinyu Lu, Yongxin Song, Junsheng Wang, Dongqing Li, Xiangchun Xuan
Particle separation has found practical applications in many areas from industry to academia. Current electrokinetic particle separation techniques primarily rely on dielectrophoresis, where the electric field gradients are generated by either active microelectrodes or inert micro-insulators. We develop herein a new type of electrokinetic method to continuously separate particles in a bifurcating microchannel. This sheath-free separation makes use of the inherent wall-induced electrical lift to focus particles towards the centerline of the main-branch and then deflect them to size-dependent flow paths in each side-branch...
September 2016: Biomicrofluidics
Yukun Ren, Weiyu Liu, Jiangwei Liu, Ye Tao, Yongbo Guo, Hongyuan Jiang
We describe a novel rotating trait of induced-charge electroosmotic slip above a planar metal surface, a phenomenon termed "Rotating induced-charge electro-osmosis" (ROT-ICEO), in the context of a new microfluidic technology for tunable particle rotation or rotational trap. ROT-ICEO has a dynamic flow stagnation line (FSL) that rotates synchronously with a background circularly polarized electric field. We reveal that the rotating FSL of ROT-ICEO gives rise to a net hydrodynamic torque that is responsible for rotating fluids or particles in the direction of the applied rotating electric field either synchronously or asynchronously, the magnitude of which is adjusted by a balance between rotation of FSL and amplitude of angular-direction flow component oscillating at twice the field frequency...
September 2016: Biomicrofluidics
Mohammad Amin Alibakhshi, Binqi Liu, Zhiping Xu, Chuanhua Duan
Control of ionic current in a nanofluidic system and development of the elements analogous to electrical circuits have been the subject of theoretical and experimental investigations over the past decade. Here, we theoretically and experimentally explore a new technique for rectification of ionic current using asymmetric 2D nanochannels. These nanochannels have a rectangular cross section and a stepped structure consisting of a shallow and a deep side. Control of height and length of each side enables us to obtain optimum rectification at each ionic strength...
September 2016: Biomicrofluidics
Ksenia Maximova, Xuewen Wang, Armandas Balčytis, Linpeng Fan, Jingliang Li, Saulius Juodkazis
Silk patterns in a film of amorphous water-soluble fibroin are created by tailored exposure to femtosecond-laser pulses (1030 nm/230 fs) without the use of photo-initiators. This shows that amorphous silk can be used as a negative tone photo-resist. It is also shown that water insoluble crystalline silk films can be precisely ablated from a glass substrate achieving the patterns of crystalline silk gratings on a glass substrate. Bio-compatible/degradable silk can be laser structured to achieve conformational transformations as demonstrated by infrared spectroscopy...
September 2016: Biomicrofluidics
Chong Hu, Han Sun, Zhengzhi Liu, Yin Chen, Yangfan Chen, Hongkai Wu, Kangning Ren
The diffusion of molecules such as nutrients and oxygen through densely packed cells is impeded by blockage and consumption by cells, resulting in a limited depth of penetration. This has been a major hurdle to a bulk (3-D) culture. Great efforts have been made to develop methods for generating branched microchannels inside hydrogels to support mass exchange inside a bulk culture. These previous attempts faced a common obstacle: researchers tried to fabricate microchannels with gels already loaded with cells, but the fabrication procedures are often harmful to the embedded cells...
July 2016: Biomicrofluidics
Seyed Ali Mousavi Shaegh, Fabio De Ferrari, Yu Shrike Zhang, Mahboubeh Nabavinia, Niema Binth Mohammad, John Ryan, Adel Pourmand, Eleanor Laukaitis, Ramin Banan Sadeghian, Akhtar Nadhman, Su Ryon Shin, Amir Sanati Nezhad, Ali Khademhosseini, Mehmet Remzi Dokmeci
There is a growing interest to develop microfluidic bioreactors and organ-on-chip platforms with integrated sensors to monitor their physicochemical properties and to maintain a well-controlled microenvironment for cultured organoids. Conventional sensing devices cannot be easily integrated with microfluidic organ-on-chip systems with low-volume bioreactors for continual monitoring. This paper reports on the development of a multi-analyte optical sensing module for dynamic measurements of pH and dissolved oxygen levels in the culture medium...
July 2016: Biomicrofluidics
Anke Lindner, Paulo E Arratia
No abstract text is available yet for this article.
July 2016: Biomicrofluidics
Ji Young Moon, Roger I Tanner, Joon Sang Lee
A red blood cell (RBC) in a microfluidic channel is highly interesting for scientists in various fields of research on biological systems. This system has been studied extensively by empirical, analytical, and numerical methods. Nonetheless, research of predicting the behavior of an RBC in a microchannel is still an interesting area. The complications arise from deformation of an RBC and interactions among the surrounding fluid, wall, and RBCs. In this study, a pressure-driven RBC in a microchannel was simulated with a three-dimensional lattice Boltzmann method of an immersed boundary...
July 2016: Biomicrofluidics
Shijie Deng, Xinglong Yu, Ran Liu, Weixing Chen, Peng Wang
A two-compartment microfluidic device integrated with a surface plasmon resonance (SPR) interferometric imaging system has been developed for long-term and real-time cell detection. The device uses a porous membrane sandwiched between two chambers to obtain an exact medium exchange rate and minimal fluid shear stress for cell culture. The two-compartment device was optimized by COMSOL simulations and fabricated using Poly (dimethylsiloxane) elastomer replica molding methods. To confirm the capability of the microfluidic device to maintain the cell physiological environment over long intervals, HeLa cells were cultured in the device for up to 48 h...
July 2016: Biomicrofluidics
Yi-Je Juang, Yu-Luen Deng, I-Chi Lee
Utilization of dissolvable, polymer microneedles (MNs) for transdermal drug delivery offers many advantages such as being painless to patients, biocompatibility, biodegradability, and active and controlled drug release. There are many different approaches for fabrication of such MNs; however, most of them still suffer from tedious procedures, stringent fabrication conditions, expensive equipment, or substantially long processing time. In this work, we applied membrane filtration to fabricate dissolvable, polymer MNs...
July 2016: Biomicrofluidics
S M Grist, S S Nasseri, T Poon, C Roskelley, K C Cheung
Three-dimensional (3-D) cell cultures are beneficial models for mimicking the complexities of in vivo tissues, especially in tumour studies where transport limitations can complicate response to cancer drugs. 3-D optical microscopy techniques are less involved than traditional embedding and sectioning, but are impeded by optical scattering properties of the tissues. Confocal and even two-photon microscopy limit sample imaging to approximately 100-200 μm depth, which is insufficient to image hypoxic spheroid cores...
July 2016: Biomicrofluidics
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