Photoactivated Selective Release of Droplets from Microwell Arrays
Photoactivated Selective Release of Droplets from Microwell Arrays
复制标题
微孔阵列中液滴的光活化选择性释放
DOI：
10.1021/acsami.9b17575
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发表时间：
2020-01-22
影响因子：
9.5
通讯作者：
Lee, Daeyeon
中科院分区：
文献类型：
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作者：
Han, Syung Hun;Choi, Yongwon;Lee, Daeyeon
液滴微流体技术能够显著减少反应体积和分析时间，这反过来又导致了高容量筛选和分析的变革性进展。通过将液滴排列成静态阵列，可以在较长的时间段内监测这些微室内发生的动态事件，从而有助于识别罕见事件和细胞类型。在许多情况下，非常希望回收少量含有独特分析物或细胞的液滴用于进一步分析;然而，很少有技术允许在不使用复杂的物理阀网络的情况下从这样的阵列选择性回收液滴，这也需要在微流体装置外部的大量控制单元。在这份报告中，我们提出了光活化的选择性释放液滴从静态微孔阵列，使光响应聚合物层集成到微流体装置。该光响应层被放置在捕获大量液滴的微孔阵列和具有或不具有可用于回收的顶部流动通道的PDMS板之间。通过使用聚焦光，光响应层可以被刺穿以用于向上释放恢复，或者通过局部加热被诱导以产生气泡以选择性地向下推释放液滴。我们表明，光响应层在可见光谱范围内是光学透明的，因此不会干扰液滴的光学观察。光声染料的类型和光响应层的物理性质可以被工程化以诱导光响应层的穿刺或将液滴推出微孔阵列，同时对液滴具有低的热影响。我们相信，光响应层将在基于软光刻的微流体装置领域产生广泛的影响，用于各种应用，包括光响应阀以及高通量单细胞测序。
Droplet microfluidics has enabled a significant reduction in reaction volume and analysis time, which in turn has led to transformative advances in high-capacity screening and assays. By arranging droplets into a static array, it is possible to monitor dynamic events that occur within these microchambers over an extended period of time, facilitating the identification of rare events and cell types. In many instances, it is highly desirable to recover a small number of droplets that contain unique analytes or cells for further analyses; however, few techniques allow for selective recovery of droplets from such an array without using a complex network of physical valves, which also require a large number of control units external to the microfluidic device. In this report, we present photoactivated selective release of droplets from a static microwell array enabled by a photoresponsive polymer layer integrated into the microfluidic device. This photoresponsive layer is placed in between a microwell array that traps a large number of droplets and a PDMS slab with or without a top flow channel that can be used for recovery. By using focused light, the photoresponsive layer can either be punctured for release-up recovery or induced to create a bubble by local heating to selectively push-down release droplets. We show that the photoresponsive layer is optically transparent within the visible spectrum and thus does not interfere with optical observation of droplets. The type of photoacoustic dye and the physical properties of the photoresponsive layer can be engineered to induce either puncture of the photoresponsive layer or pushing of droplets out of the microwell arrays with low thermal impact on the droplets. We believe that the photoresponsive layer will have a broad impact in the field of soft lithography-based microfluidic devices for various applications including photoresponsive valves as well as high-throughput single-cell sequencing.