The generation and manipulation of small aqueous droplets is an important issue for nano- and biotechnology, particularly, when using microfluidic devices. The production of very small droplets has been frequently carried out by applying intense local electric fields to the fluid, which requires power supplies and metallic electrodes. This procedure complicates the device and reduces its versatility. In this work, we present a novel and flexible, to the best of our knowledge, electrodeless optoelectronic method for the production of tiny droplets of biologically friendly aqueous fluids. Our method takes advantage of the photoinduced electric fields generated by the bulk photovoltaic effect in iron-doped lithium niobate crystals. Two substrate configurations, presenting the polar ferroelectric axis either parallel or perpendicular to the active surface, have been successfully tested. In both crystal geometries, small droplets on the femtoliter scale have been obtained, although with a different spatial distributions correlated with the symmetry of the photovoltaic fields. The overall results demonstrate the effectiveness of the optoelectronic method to produce femtoliter droplets, both with pure water and with aqueous solutions containing biological material.

中文翻译：

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基于整体光伏效应的生物水性毫微微液滴的光电生成。

小水滴的产生和处理对于纳米技术和生物技术而言是一个重要的问题，特别是在使用微流体设备时。通常通过向流体施加强烈的局部电场来产生非常小的液滴，这需要电源和金属电极。该过程使设备复杂化并降低了其多功能性。在这项工作中，据我们所知，我们提出了一种新颖而灵活的无电极光电方法，用于生产生物友好的水性流体的微小液滴。我们的方法利用了铁掺杂铌酸锂晶体中由于整体光伏效应而产生的光感应电场。两种基材配置，具有平行或垂直于有效表面的极性铁电轴的磁头已经成功地进行了测试。在两种晶体几何结构中，均获得了飞升级的小液滴，尽管其空间分布与光伏场的对称性有关。总体结果证明了用光电方法用纯水和含有生物材料的水溶液生产飞升液滴的有效性。