微液滴/注液表面黏附行为的主被动控制及机理  

Active/Passive Control and Mechanism of the Adhesion Behaviors of Droplet/Liquid-infused Surface

作　　者：张学仁 张亚锋[1] 顾兴士 余家欣[1] ZHANG Xue-ren;ZHANG Ya-feng;GU Xing-shi;YU Jia-xin(Key Laboratory of Testing Technology for Manufacturing Process,Ministry of Education,Southwest University of Science and Technology,Sichuan Mianyang 621010,China;Key Laboratory of Icing and Anti/De-icing,China Aerodynamics Research and Development Center,Sichuan Mianyang 621000,China)

机构地区：[1]西南科技大学制造过程测试技术教育部重点实验室,四川绵阳621010 [2]中国空气动力研究与发展中心结冰与防除冰重点实验室,四川绵阳621000

出　　处：《表面技术》2023年第10期304-312,共9页Surface Technology

基　　金：四川省科技厅项目(2022ZHCG0050);中国空气动力研究与发展中心结冰与防除冰重点实验室开放课题(IADL20210103,IADL20210403)。

摘　　要：目的提出一种微液滴/注液表面黏附行为主/被动控制方法,探究在电压和流体黏度耦合作用下微液滴/注液表面黏附行为动态可调机理。方法在P型硅片表面制备超疏水层,注入黏度分别为10、50、100 mm2/s的聚二甲基硅油制得注液表面,使用固液界面行为测试仪探究不同黏度和外加电压下微液滴/注液表面的黏附行为。结果当聚二甲基硅油黏度从10 mm2/s增加到100 mm2/s,微液滴/注液界面润湿力从194μN减小到123μN,最大相互作用力从129μN减小到94μN,分离力从101μN减小到82μN;当电压从0V增加到240V时,润湿力从156μN增加到322μN左右,最大相互作用力从120μN增加到178μN左右,分离力从85μN减小到53μN左右,实现了黏附力的动态调节。结论高黏度聚二甲基硅油内部具有较强的剪切力,但是长链会增强微液滴/注液表面氢键作用,在2种作用形式的耦合下,润湿力、最大相互作用力以及分离力随黏度的增加而减小。在电压作用下,微液滴在注液表面产生电润湿行为,有效界面能随电压发生非线性响应,实现了固液界面黏附力的实时调节。微液滴/注液表面可以通过改变电压与润滑油的黏度实现黏附行为的主/被动的调节。Controlling microdroplets has gotten wide attention due to its potential applications in drug delivery,microfluidic devices and lab on chip,etc.Recently,various methods were used to manipulate microdroplet.For example,surfaces were modified by coating with different surface energy,or by micro-structures to change the property of surface to manipulate microdroplet.These methods were classified as passive methods because the functions of the surface could not be changed when the surface was modified.Moreover,active methods,such as temperature,light,electricity,magnetism and mechanical stress,etc.were used to manipulate microdroplet dynamically.However,although the adhesion behavior at liquid/solid interface could be adjusted,some obstacles such as long response time,high energy consumption and droplet pollution,limited the application of those technologies.Therefore,a combined active and passive approach was required to manipulate microdroplets with fast response time,low energy consumption,and no pollution.In this study,silicon chip with size of 20 mm×20 mm was used as substrate.To ensure the conductivity,the back of the silicon chip was ground with sandpaper to remove the oxide layer.Then,the silicon chip was coated by spraying superhydrophobic liquid.After drying for 1 h,the superhydrophobic film was formed.The liquid-infused surfaces were prepared by adding lubricating oil(polydimethylsiloxane)to the superhydrophobic surface.Droplet was placed on the oil-infused surface and then electrowetting system on the droplet/oil-infused surface was established with applied voltage.Lubricant with viscosity of 10 mm2/s,50 mm2/s and 100 mm2/s and applied voltage(0-240 V)were used in this work.Moreover,the effect of oil viscosity and applied voltage on the droplet/oil-infused surface adhesion behaviors was investigated.The adhesion mechanisms under the coupling effects of lubricating oil viscosity and applied voltage were studied.The adhesion force variation process could be described with snap-in force,maximum force and pu

关 键 词：微液滴 注液表面 黏附 电润湿 界面调控 

分 类 号：TH136[机械工程—机械制造及自动化]