【作者】 何鑫尧； 冯林； 石万元；

【Author】 He Xinyao;Feng Lin;Shi Wanyuan;School of Energy and Power Engineering,Chongqing University;Key Laboratory of Low-grade Energy Utilization Technologies and Systems,Ministry of Education;

【机构】 重庆大学能源与动力工程学院； 重庆大学低品位能源利用技术及系统教育部重点实验室；

【摘要】 磁力操控是液滴微流控技术的重要分支。目前,国内外学者主要关注在磁场作用下磁性液滴的迁移规律,对非磁性液滴的迁移研究较少。本文采用化学刻蚀法在紫铜基板表面制备微纳结构,并灌注润滑油形成超滑表面。采用圆柱形永磁体(表磁强度400 mT)产生非均匀磁场,通过移动磁铁驱动液滴运动,实验研究了非均匀磁场驱动超滑表面上纯水液滴迁移现象,获取了润滑油粘度、液滴体积、磁场强度及磁场梯度对液滴迁移运动的影响。研究发现:液滴迁移速度随润滑油粘度的减小而增加,迁移速度可达1 mm/s;随着液滴体积的增加,液滴与磁铁的水平距离逐渐增大,液滴的临界迁移速度逐渐增加;而随着磁铁与液滴垂直距离的减小,液滴与磁铁的水平距离和液滴的临界迁移速度都呈先增加后减小的趋势。液滴迁移速度与磁场梯度和水平夹角紧密相关。更多还原

【Abstract】 Magnetic manipulation of liquid droplet is an important approach of droplet microfluidic technology.So far,the migration of magnetic droplets has been investigated numerously while there are few studies on the non-magnetic droplets.In this paper,the droplet migration on the ultra-slippery surface under the action of a non-uniform magnetic field was studied experimentally.The effects of the viscosity of lubricating oil,droplet volume,magnetic field strength and magnetic field gradient on the migration velocity of droplet are determined.It is found that the droplet migration velocity increases with the decrease of lubricating oil viscosity,and the maximum migration velocity was measured to be 1 mm/s.With the increase of droplet volume,the horizontal distance between droplet and magnet increases gradually,and the critical migration velocity of the droplet increases gradually.With the decrease of the vertical distance between magnet and droplet,both the horizontal distance and critical migration velocity increases first and then decreases gradually.The migration velocity of droplet is closely related to the gradient of magnetic field and the angle between horizontal plane.更多还原