Droplets with predefined sizes have been controllably produced at the tip of a micro-capillary immersed in an external fluid while tracking the high Q-factor whispering gallery modes (WGM). The modes were fitted to a model to give precise real-time size measurement, which was used as a feedback to control the pressure in the capillary and the release of the droplet from the capillary when it reached the target size. In this way a dispersion of highly monodisperse droplets anywhere in the size range from 5 μm to 50 μm were produced. To fabricate solid beads, the droplets were made from a liquid photopolymer and were later polymerized with UV light. The polymerized beads showed long term stability. The diameter of the generated oil droplets and polymerized microbeads could be reproduced with a standard deviation of 1.1 nm and 20 nm, respectively. Overall, the demonstrated method improves the size precision by three and two orders of magnitude for microdroplets and microbeads, respectively, compared to standard production methods such as reported in microfluidics. Encoding of short words and numbers has been demonstrated by producing three beads with predefined sizes. The stored information has been read from the emitted spectrum.

中文翻译：

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光共振辅助产生的纳米级超级单分散微滴和微珠。

在跟踪高Q因子耳语通道模式（WGM）的同时，在浸入外部流体的微毛细管尖端可控地产生了具有预定大小的液滴。这些模式适合模型以提供精确的实时尺寸测量，该测量值用作反馈，以控制毛细管中的压力以及当液滴达到目标大小时从毛细管中释放液滴。以这种方式产生高度单分散的液滴的分散体，其大小在5μm至50μm的范围内。为了制造固体珠粒，由液体光敏聚合物制成小滴，然后用紫外线将其聚合。聚合的珠粒显示出长期稳定性。产生的油滴和聚合的微珠的直径可以分别以1.1 nm和20 nm的标准偏差再现。总体而言，与标准生产方法（如微流控技术中报道的）相比，该方法对微滴和微珠的尺寸精度分别提高了三个和两个数量级。通过产生三个具有预定义大小的珠子，已经证明了短单词和数字的编码。已从发射光谱中读取了存储的信息。