A New Method to Actuate a Droplet on a Plate by Use of Laser Irradiation to Improve Wettability
A New Method to Actuate a Droplet on a Plate by Use of Laser Irradiation to Improve Wettability
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DOI：
10.11395/jjsem.13.19
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发表时间：
2013-03
期刊：
影响因子：
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通讯作者：
T. Wakimoto;Yuzo Sato;K. Katoh
中科院分区：
文献类型：
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作者：
T. Wakimoto;Yuzo Sato;K. Katoh
提出了一种驱动板上小液滴的新方法。激光束照射在 SAM（自组装单分子层）板上的液滴的一端。由于加热侧的润湿性显着改善，表面张力的切向分量将液滴拉向激光束的光点。在本报告中，当液滴开始在板上滑动时，通过实验估计了切向方向的合力。为了获得接触角的温度依赖性，在将激光束均匀地照射在液滴上的同时测量轴对称液滴轮廓。温度是根据拉普拉斯方程的解与实验液滴轮廓之间的比较确定的表面张力来估计的。根据测量的接触角与温度的关系，计算当激光束照射在液滴一端时，在液滴两端作用于液滴圆周上的表面张力的合力。计算结果表明，当液滴开始滑动时，合力实际上是正的并且迅速增加。
A new method to actuate a small droplet on a plate is proposed. A laser beam is irradiated on one end of the droplet set on a SAMs (Self-Assembled Monolayers) plate. Since the wettability at the heated side is improved remarkably, the tangential component of surface tension pulls the droplet toward the spot of laser beam. In this report, the resultant force in the tangential direction is estimated experimentally when the droplet starts to slide on the plate. In order to obtain the temperature dependence of contact angles, the axi-symmetric droplet profile is measured while irradiating the laser beam homogeneously over the droplet. The temperature is estimated from the surface tension determined from the comparison between the solution of Laplace equation and experimental droplet profile. Based on the measured temperature dependence of contact angles, the resultant of surface tension acting on the circumference of droplet is calculated at both ends of droplet when the laser beam is irradiated on the one end. The calculated results show that the resultant force is actually positive and rapidly increases when the droplet starts to slide.