Research Center for Analytical Sciences, Northeastern University, Shenyang, 110819, China.
Lab Chip. 2021 Mar 21;21(6):1131-1138. doi: 10.1039/d0lc01324b. Epub 2021 Feb 3.
In this work, we developed a digital microfluidic platform based on a shape memory micropillar array responsive to near-infrared light, and the droplets were programmatically manipulated through light-induced micropillar deformation. The micropillar array was constructed on the surface of a poly(ethylene-vinyl acetate) copolymer, a shape memory polymer sensitive to near-infrared light. Before droplet manipulation, the micropillar array was kept temporarily tilted by heating and pressing. Under the irradiation of a near-infrared laser, the micropillar array achieved the transition from the temporary shape to the original shape. Temperature gradient and micropillar deformation caused by near-infrared light irradiation produce the driving force for droplet movement. The movement of the laser mounted on an electronically controlled displacement platform was controlled by a computer to achieve the programmed control of the droplets. Moreover, we demonstrated light-manipulated droplet movement and fusion, and achieved ascorbic acid detection using this digital microfluidic platform. In particular, the micropillar array chip is able to manipulate droplets in a wide range of 0.1 μL to 10 μL. The proposed digital microfluidic platform will broaden the application of digital microfluidic technology in analytical chemistry and biomedicine.
在这项工作中，我们开发了一种基于近红外光响应的形状记忆微柱阵列的数字微流控平台，通过光诱导微柱变形来对液滴进行程序化操作。微柱阵列构建在聚（乙烯-醋酸乙烯酯）共聚物表面，该聚合物是一种对近红外光敏感的形状记忆聚合物。在进行液滴操作之前，通过加热和按压将微柱阵列暂时倾斜固定。在近红外激光照射下，微柱阵列实现了从临时形状到原始形状的转变。近红外光照射产生的温度梯度和微柱变形为液滴运动提供了驱动力。安装在电控位移平台上的激光的运动由计算机控制，以实现对液滴的程序化控制。此外，我们展示了光控液滴运动和融合，并使用该数字微流控平台实现了抗坏血酸检测。特别是，微柱阵列芯片能够在 0.1μL 到 10μL 的广泛范围内操控液滴。所提出的数字微流控平台将拓宽数字微流控技术在分析化学和生物医学中的应用。
