叙述了一种模拟电介质电润湿(electrowetting on dielectric,EWOD)下的微液滴的运动的数值方法.采用二阶投影法求解N_S方程和level set函数,并利用零level set函数俘获液滴运动界面,在液体与固体接触的边界上,通过引入动态接触角表征电...叙述了一种模拟电介质电润湿(electrowetting on dielectric,EWOD)下的微液滴的运动的数值方法.采用二阶投影法求解N_S方程和level set函数,并利用零level set函数俘获液滴运动界面,在液体与固体接触的边界上,通过引入动态接触角表征电介质表面润湿性随电势的改变.数值计算基于MAC网格,模拟了2维微管道内与固体壁面接触的变润湿性的两种液体的分界面形状、平板上的微液滴在不同电势作用下处于不同湿润性的形态,以及微管道内改变接触角液滴的运动变形过程等算例.展开更多
The shape of liquid interfaces can be precisely controlled using electrowetting,an actuation mechanism which has been widely used for tunable optofluidic micro-optical components such as lenses or irises.We have expan...The shape of liquid interfaces can be precisely controlled using electrowetting,an actuation mechanism which has been widely used for tunable optofluidic micro-optical components such as lenses or irises.We have expanded the considerable flexibility inherent in electrowetting actuation to realize a variable optofluidic slit,a tunable and reconfigurable two-dimensional aperture with no mechanically moving parts.This optofluidic slit is formed by precisely controlled movement of the liquid interfaces of two highly opaque ink droplets.The 1.5mmlong slit aperture,with controllably variable discrete widths down to 45 mm,may be scanned across a length of 1.5mmwith switching times between adjacent slit positions of less than 120 ms.In addition,for a fixed slit aperture position,the width may be tuned to a minimum of 3 mmwith high uniformity and linearity over the entire slit length.This compact,purely fluidic device offers an electrically controlled aperture tuning range not achievable with extant mechanical alternatives of a similar size.展开更多
文摘叙述了一种模拟电介质电润湿(electrowetting on dielectric,EWOD)下的微液滴的运动的数值方法.采用二阶投影法求解N_S方程和level set函数,并利用零level set函数俘获液滴运动界面,在液体与固体接触的边界上,通过引入动态接触角表征电介质表面润湿性随电势的改变.数值计算基于MAC网格,模拟了2维微管道内与固体壁面接触的变润湿性的两种液体的分界面形状、平板上的微液滴在不同电势作用下处于不同湿润性的形态,以及微管道内改变接触角液滴的运动变形过程等算例.
基金funded by the German Research Foundation DFG within the Priority Program Active Micro-optics(SPP 1337).
文摘The shape of liquid interfaces can be precisely controlled using electrowetting,an actuation mechanism which has been widely used for tunable optofluidic micro-optical components such as lenses or irises.We have expanded the considerable flexibility inherent in electrowetting actuation to realize a variable optofluidic slit,a tunable and reconfigurable two-dimensional aperture with no mechanically moving parts.This optofluidic slit is formed by precisely controlled movement of the liquid interfaces of two highly opaque ink droplets.The 1.5mmlong slit aperture,with controllably variable discrete widths down to 45 mm,may be scanned across a length of 1.5mmwith switching times between adjacent slit positions of less than 120 ms.In addition,for a fixed slit aperture position,the width may be tuned to a minimum of 3 mmwith high uniformity and linearity over the entire slit length.This compact,purely fluidic device offers an electrically controlled aperture tuning range not achievable with extant mechanical alternatives of a similar size.
