The Mechanism And Experiment Of Flexible Droplet Transport Controlled By The Combination Of Electric And Magnetic Fileds

Micro-nano motors which can accomplish many tasks in a small space,are an important tool for precise control of small-scale targets.Over the past decade,micro-nano motors have gradually achieved high-precision automatic control.In addition,through the cross-combination with the material field,it directly realizes its sensing,driving and control functions in the material.It should be pointed out that the micro-nano motor combined with the field of materials science has already possessed the deformation characteristics and became a typical flexible micronano robot.At present,most flexible micro-nano robots have a sheet or linear structure,and external stimulation enable micro-nano robots to perform flexible deformation operations such as bending and turning.But this type of robot cannot pass the channel structure which is narrower than its own size smoothly.Based on this,this paper presents a design for a magnetically guided flexible droplet.By adding nano-sized nickel particles to the droplet,it can pass through the slit channel under the control of the magnetic field.Then combine with the electronic control experiment to prove its significance in the medical field.First,the behaviors of flexible droplet generation,deformation and electric field manipulation are theoretically derived.Combining with the multi-phase flow microfluidic theory,the droplet forming mechanism in the trickle mode is analyzed,and the prediction formula of the droplet diameter is further deduced.The deformation and force of magnetically guided flexible droplets when they pass through different slit structures under the action of magnetic field is described.The mechanism of double emulsion droplet core release and droplets fusion is deeply studied by Electrohydro Dynamics.Secondly,on the basis of theoretical research,a flexible droplet generation and deformation simulation model is established.Using the phase field method,a droplet generation model is constructed to analyze the droplet generation process;on the basis of the phase field,a magnetic field physics field is introduced to construct a flexible droplet deformation model to discuss the influence of external factors on the droplet deformation so as to lay the foundation for experimental research.Third,experiments on the generation and deformation of flexible droplets were conducted.We develop droplet microfluidic chips,generate magnetically guided flexible droplets of different structural forms,evaluate their flexible performance,and determine the optimal composition of flexible droplets;then,we make deformed channel chips,build experimental platforms to achieve steady movement of flexible droplets within the slit structure.Finally,the electric field manipulation simulation of flexible droplets is carried out.The simulation software was used to establish the fusion model of flexible droplets and the release model of composite droplets.The effect of droplet size and electric field conditions on the electrical control behavior of droplets was further studied.On this basis,a comprehensive electrical control simulation of droplets first released and then fused was realized at a safe voltage of 36 V,preparing for subsequent experimental research in the medical field.