School of Physics & Technology, Key Laboratory of Artificial Micro/Nano Structure of Ministry of Education, Wuhan University, Wuhan 430072, China.
Lab Chip. 2017 Sep 26;17(19):3258-3263. doi: 10.1039/c7lc00598a.
Liquid-liquid (L) microlenses have great potential for various applications in imaging and detection systems. Traditional L microlenses are almost two-dimensional (2D) due to the modulation of flow rates in planer chips. Fundamental difficulties in effective application to cell imaging and analysis arise due to the limitations of 2D profiles. Herein, we demonstrate the feasible design of three-dimensional (3D) L biconvex lenses to detect flowing cells. Using the auxiliary curved microchannels, a 3D L lens is formed using Dean flow. The shape of the 3D biconvex lens and its focal length can be modulated by tuning the flow rates of the liquids. 3D light focusing was successfully achieved and the focal length could be modulated by around 435 μm, from 3554 μm to 3989 μm, in the experiment. The numerical aperture of the 3D L lens was also measured and its range was 0.175-0.198. Compared to a traditional objective lens with the same magnification (4×/0.1), the resolution of the 3D L biconvex lenses was improved 1.79-fold due to being completely immersed in liquid. Mouse myeloma cells sp2/0 and acute promyelocytic leukemia cells NB4 were imaged in the contrast experiments. The time response of experimental manipulation was about 2.7 ms. This 3D biconvex lens has great application prospects for cell imaging and analysis systems in lab-on-a-chip settings.
液-液相（L）微透镜在成像和检测系统的各种应用中具有巨大的潜力。由于在平面芯片中流速的调制，传统的 L 微透镜几乎是二维（2D）的。由于 2D 轮廓的限制，在细胞成像和分析中的有效应用中出现了基本困难。在此，我们展示了用于检测流动细胞的三维（3D）L 双凸透镜的可行设计。使用辅助弯曲微通道，使用迪恩流形成 3D L 透镜。通过调节液体的流速，可以调节 3D 双凸透镜的形状和焦距。在实验中，成功实现了 3D 光聚焦，并且焦距可以在 3554 μm 到 3989 μm 的范围内调节，大约 435 μm。还测量了 3D L 透镜的数值孔径，其范围为 0.175-0.198。与具有相同放大倍数（4×/0.1）的传统物镜相比，由于完全浸入液体中，3D L 双凸透镜的分辨率提高了 1.79 倍。在对比实验中对小鼠骨髓瘤细胞 sp2/0 和急性早幼粒细胞白血病细胞 NB4 进行了成像。实验操作的时间响应约为 2.7 ms。这种 3D 双凸透镜在微流控芯片设置中的细胞成像和分析系统中有很大的应用前景。
