Takamatsu Yuka, Yamato Chizuru, Kuwahara Masashi, Saito Yuta, Saiki Toshiharu
Graduate School of Science and Technology, Keio University, Yokohama 223-8522, Kanagawa, Japan.
National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8560, Ibaraki, Japan.
Micromachines (Basel). 2023 Jul 21;14(7):1460. doi: 10.3390/mi14071460.
We present a sessile droplet manipulation platform that enables the formation and transport of a droplet on a light-absorbing surface via local laser-beam irradiation. The mechanism relies on solutocapillary Marangoni flow arising from a concentration gradient in a binary mixture liquid. Because the mixture is strongly confined in a two-dimensional slit with a spacing of a few micrometers, the wetting film is stably sustained, enabling the rapid formation, deformation, and transport of a sessile droplet. In addition, to sustain the droplet in the absence of laser irradiation, we developed a method to bridge the droplet between the top and bottom walls of the slit. The bridge is stably sustained because of the hydrophilicity of the slit wall. Splitting and merging of the droplet bridges are also demonstrated.
我们展示了一种固定液滴操纵平台，该平台能够通过局部激光束照射在光吸收表面上形成并传输液滴。其机制依赖于二元混合液体中浓度梯度产生的溶质毛细马兰戈尼流。由于混合物被强烈限制在间距为几微米的二维狭缝中，润湿膜得以稳定维持，从而实现固定液滴的快速形成、变形和传输。此外，为了在无激光照射的情况下维持液滴，我们开发了一种方法，使液滴在狭缝的顶壁和底壁之间形成桥接。由于狭缝壁的亲水性，该桥接得以稳定维持。我们还展示了液滴桥接的分裂和合并。
