【作者】 刘彤；

【导师】 陈伟平；

【作者基本信息】 哈尔滨工业大学 ， 集成电路工程（专业学位）， 2019， 硕士

【摘要】 液滴的操作诸如转移、分离、混合、运输等具有很高的实际应用价值,特殊浸润性表面上液滴的定位输运因其能快速、可重复地实现对液滴的有效控制而在生化分析、微流体系统、临床诊断等领域具有较高研究价值和应用前景。然而,目前特殊浸润性表面液体定位输运手段存在制备方法繁琐、成本较高、需要额外能量或系统输入等问题,并不能满足实际应用的需求。针对以上问题,本课题首先介绍了关于固体表面浸润性的基本理论及经典模型,并分别研究了液滴在梯度深度的超疏水-超疏水轨道和超疏水-超亲水轨道上的运输原理。基于以上理论,本课题通过仿真研究了液滴在不同参数的深度梯度轨道上的运动情况。仿真结果表明:液滴在超疏水-超疏水轨道上进行输运时,轨道宽度越宽、轨道最大深度越深,液滴越不容易脱离轨道;而液滴在超疏水-超亲水轨道上进行输运时,轨道宽度不宜过大,此时轨道越宽、轨道最大深度越深,液滴受到的毛细力吸附作用越强,液滴越不容易脱离轨道。接下来通过实验采用不同的特殊浸润性表面制备方法在铝合金基底上分别制备了“迷宫”状微结构、树状微结构及分级微纳米结构的三种表面微结构。通过对比接触角、滚动角、表面平整度等性能,最终选择运用化学刻蚀与阳极氧化相结合的方法作为本课题制备铝基超疏水表面的主要方法,制备的超疏水表面接触角为164°,滚动角为1.5°。然后利用紫外激光精细微加工设备在铝合金基底上制备出具有深度梯度的超疏水-超疏水和超疏水-超亲水液滴定位输运轨道,分别制备了直线形、曲线形和圆形输运轨道,并在其上进行液滴的定位输运实验。实验结果表明:对于梯度超疏水-超疏水轨道,液滴在宽度合适的直线形轨道上能以任何速度进行输运,在弯曲轨道上时,当轨道宽度为1mm、轨道最大深度为450μm时,液滴的输运能力较好,不易脱离轨道。对于梯度超疏水-超亲水轨道,轨道宽度为100μm时输运效果较好,曲率半径为12mm的弯曲轨道能承受液滴较大的临界运动速度,液滴更不容易脱离轨道;而较长的直线段路径会使液滴获得更大运动速度,对于相同曲率半径的弯曲轨道,液滴越容易发生脱离。最后实现了液滴在宽度为100μm,最大深度为200μm,曲率半径为10mm的圆形梯度超疏水-超亲水轨道上的定位输运。更多还原

【Abstract】 The operation of droplets,such as transfer,separation,mixing and transportation,has high practical application value.The location transportation of droplets on special infiltrating surface has high research value and application prospect in biochemical analysis,microfluidics system,clinical diagnosis and other fields because of its rapid and repeatable effective control of droplets.However,at present,the special wetting surface liquid positioning transportation methods have some problems,such as cumbersome preparation method,high cost,extra energy or system input,etc.,which cannot meet the requirements of practical application.In view of the above problems,this paper first introduces the basic theory and classical model of solid surface wettability,and the principle of transport of droplets on the superhydrophobic-superhydrophobic orbital and superhydrophobic-superhydrophilic orbits of gradient depth is studied separately.Based on the above theories,this paper studies the motion of droplets on the depth gradient orbit of different parameters through simulation.The simulation results show that when the droplets are transported on the superhydrophobic-superhydrophobic orbit,the wider the orbital width and the deeper the maximum depth of the orbit,the less likely the droplet is to get out of the orbit.When the droplets are transported on the super-hydrophobic and super-hydrophilic orbit,the orbital width should not be too large.At this time,the wider the orbit,the deeper the maximum depth of the orbit,the stronger the capillary force is absorbed by the droplets,and the less likely the droplet is to get out of the orbit.Then three kinds of surface microstructures,such as "maze" microstructures,"tree" microstructures and hierarchical micronanostructures,were prepared on aluminum alloy substrate by different methods of special wetting surface preparation.By comparing the properties of contact Angle,rolling Angle and surface flatness,the method of chemical etching combined with anodic oxidation was finally selected as the main method to prepare aluminum superhydrophobic surface in this project,the prepared superhydrophobic surface has a contact angle of 164° and a roll angle of 1.5°.Then,the liquid droplet positioning and transport orbits with superhydrophobicsuperhydrophobic and superhydrophobic-superhydrophilic with depth gradient were prepared on aluminum alloy substrate by using ultraviolet laser fine processing equipment,the linear,curved and circular transport orbits were prepared respectively,on which the location transport experiment of liquid droplets was carried out.The experimental results show that for the gradient superhydrophobic-superhydrophobic orbit,the droplet can transport at any speed in the linear orbit with appropriate width,when the droplets are in a curved orbit,when the orbital width is 1 mm and the maximum depth of the orbit is 450 μm,the droplets have good transport capacity and are not easily separated.track For the gradient superhydrophobic-super-hydrophilic orbit,the transport effect is better when the orbital width is 100μm,and the curved orbit with a curvature radius of 12 mm can withstand the critical critical velocity of the droplet,and the droplet is less likely to get out of the orbit;The straight segment path will cause the droplet to achieve a greater velocity of movement,and for curved orbits of the same radius of curvature,the droplet will more likely to detach.Finally,the positioning and transport of the droplets on a circular gradient superhydrophobicsuperhydrophilic orbit with a width of 100 μm,a maximum depth of 200 μm and a radius of curvature of 10 mm was achieved.更多还原