The Study And Development Of Micromanipulation Methods Using A Liquid-drop Manipulator

With the development of the microelectromechanical system(MEMS),the components also tend to be miniaturized and thinned,which put forward increasing requirements for Microassembly Technology.Micro object picking up,orientation adjusting and releasing are important parts in micro-operation.Because effect of surface tension in micro scale is dominated and less susceptible to outside interference,and droplet can be compliant deformation for various shapes of micro-object,so the micromanipulation method based on liquid surface tension,is becoming an indispensable part of micro-operation.In this paper,the micromanipulation method based on liquid-droplet is studied.First,the mechanism and physical process of the orientation adjustment using liquid-droplet micromanipulator are analyzed.The relationship between the micro-object's orientation and manipulator tip's configuration is discussed,and their quantitative mapping relationship is established.A quantitative control method for tilt and rotation of micro-object is proposed.Then,a micromanipulation method based on liquid bridge configuration is proposed.The mathematical model of liquid bridge is established,and the influence of the liquid bridge meniscus on the liquid bridge force is analyzed in detail.The release method and physical process of the micro-objects are discussed.The effects of the parameters of the liquid bridge,the motion velocity of the manipulator and the parameters of droplet on the release performance are analyzed by the simulation.Based on the above analysis,an experimental platform is built,and the effectiveness of the proposed method is demonstrated by extensive experiments.The experimental and research results show that the orientation of the micro-object adsorbed by liquid-drop manipulator is changed by the orientation of the manipulator tip.The quantitative orientation of the micro-objects can be realized based on the mapping relation between the manipulator tip's orientation,the manipulator tip's constraint,and micro-object's orientation,via controlling the motion of tungsten rods.By controlling the liquid bridge configuration,the liquid bridge force can be changed,and the release of micro-objects can be realized.When the size,quality of the micro-objects and the release surface change,the requirements for the release of micro-objects with various shape can be satisfied,according to the mapping relationship of the release objects established by the experiment.