芯片实验室

Abstract(#br)SU-8 and polydimethylsiloxane (PDMS) are both transparent materials with properties very convenient for rapid prototyping of microfluidic systems. However, previous efforts of combining these two materials failed due to poor adhesion between them. Herein, we introduce a promising low-temperature technique (\u003c 100 °C) to irreversibly bond two or more structured layers of SU-8 and PDMS to create hybrid stacks. This offers new possibilities in design and fabrication of enclosed three-dimensional microstructures and microchannels with simple soft-lithography techniques.

Abstract(#br)DNA extraction automation is a major concern in molecular diagnostic where processing of numerous and daily samples of blood represent a labor-intensive task and are difficult to automate. With the rapid growth in the area of DNA diagnostics, there is an URGENT need for the development of a micro total analysis system which can do all the three main steps involved during nucleic acid-based diagnostics: sample preparation, extraction of the DNA, detection and quantification on one SINGLE chip.

Abstract(#br)Here we present a capillary-driven microfluidic chip for “one-step” immunoassays. The chip allows for easy modification of several assay parameters such as the flow rates of sample, the volumes of samples for tests, and the type of reagents and receptors for detecting analytes. We therefore term such a chip a multiparametric chip and illustrate this concept with the integration and release of anti-C-reactive protein (CRP) detection antibodies (dAbs) together with splitting flow of samples containing CRP across lines of anti-CRP capture antibodies (cAbs).

Abstract(#br)Investigations on surface properties of poly(dimethylsiloxane) (PDMS) are justified by its large application ranges especially as coating polymer in fluidic devices. At a micrometer scale, the liquid dynamics is strongly modified by interactions with a solid surface. A crucial parameter for this process is microchannel wettability that can be tuned by acting on surface chemistry and topography. In literature, a number of multi-step, time and cost consuming chemical and physical procedures are reported.

Abstract(#br)Microfluidics-based lab-on-a-chips have many advantages, one of which is to provide physiologically relevant settings for cell biology experiments. Thus there is an ever increasing interest in their fabrication. Our goal is to construct three dimensional (3D) Controlled in vitro Microenvironments (C iv Ms) that mimic the in vivo microenvironments. Here, we present our optimized fabrication method that works for various lab-on-a-chip designs with a wide range of dimensions.

Abstract(#br)In this paper, we present useful technique for fabrication of novel photonic devices created in the polydimethylsiloxane (PDMS). We use combination of direct laser writing in thin photoresist layer with embossing process of liquid PDMS. We prepared ring resonator and Mach-Zehnder interferometer in PDMS. The shape of prepared PDMS photonic devices was analyzed by confocal laser microscope and atomic force microscope. Optical characterization of these devices reveals extinction ratios of up to 20\u003cce:hsp sp=\"0.25\"/\u003edB.

Intermittent hypoxia (IH), a hallmark of obstructive sleep apnea (OSA), plays a critical role in the pathogenesis of OSA-associated morbidities, especially in the cardiovascular and respiratory systems. Oxidative stress and inflammation induced by IH are suggested as main contributors of end-organ dysfunction in OSA patients and animal models. Since the molecular mechanisms underlying these in vivo pathological responses remain poorly understood, implementation of experimental in vitro cell-based systems capable of inducing high-frequency IH would be highly desirable.

提出了一种集成聚合物基磁流体动力学( MHD )泵，该泵可在闭路装置中驱动盐水流体。MHD泵由于能够在不需要任何运动部件的情况下提供较高的推进力，因而对片上实验室应用具有吸引力。与其他MHD器件不同，钕铁硼-聚二甲基硅氧烷永磁复合基底中既包含激光诱导石墨烯( LIG )电极，也包含钕铁硼磁通源，显示了较高的集成度。研究了将LIG薄膜从聚酰亚胺转移到磁性复合基板上的效果。实现了集成磁流体动力泵的无扰流气泡运行。在所研究的情况下，泵的流量为28.1 µ L / min，功耗为~ 1 mW。

将一个PDMS (聚二甲基硅氧烷)微流控通道与紫外可见光纤光谱仪和新合成的比色探针耦合，集成到基于光流控的Lab-on-a芯片装置中，用于氟离子( F ¯ )的高灵敏实时定量测量。在微流控装置中设计了一个‘S’形微通道作为微反应器，以利于合成的比色探针(传感器)与F ¯离子之间的连续反应。在此反应后，在微流控器件的下游检测区利用紫外-可见探针捕获其光谱，并实时呈现为F ¯浓度。初步研究了- OH、- NH和- NO2等多种结合基团和发色基团的多色变比色探针对F ¯离子的高灵敏度和高选择性，检出限为0.79   ppm。对所研制的光流化装置的性能进行了评价，用于包括真实样品在内的F ¯离子的选择性、敏感性检测，优于常规方法。该技术具有样品用量少、分析快速、灵敏度高、可移植等优点。提出的新型片上Lab-on-a器件为跨越宽扇区所需F ¯离子的实时分析提供了许多竞争优势。

纳米粒子( NPs )被用于各种医药应用。外泌体( Exosomes )是一种生物衍生的纳米颗粒，是通过从体液中分离和浓缩而获得的生物标志物。基于聚二甲基硅氧烷( PDMS )的微通道具有高透气性和低细胞毒性等优点，适合于纳米颗粒的精细处理。然而，纳米颗粒的大比表面积可能导致非特异性吸附在器件基底上，从而造成样品的损失。因此，了解NP在微通道上的吸附情况对用于NP处理的微流控器件的运行至关重要。本文利用原子力显微镜对NP在PDMS基片和微通道上的吸附行为进行了表征，并将NP的吸附行为与NP的静电作用和分散介质性质联系起来。当聚苯乙烯NP分散体以恒定的流速引入PDMS基微通道时，随着NP和微通道zeta电位的降低(即随着pH的升高)，吸附的纳米颗粒数量减少，表明微通道与纳米颗粒之间的静电作用增强了它们的斥力。在恒定流速下，将exosome分散体引入不同润湿性的PDMS微通道中，exosome的吸附以静电作用为主。所得结果将有助于PDMS基微流控装置对纳米颗粒的预富集、分离和传感。