Research On The Fabrication Of Marangoni Actuators And Their Multi-field Coupled Manipulation

The stimuli-responsive actuator can transform the chemical or physical energy in the natural environment into mechanical energy,such as light,heat,magnet,electric and other energy into kinetic energy for motion.And the stimuli-responsive actuator has wireless control function,so it has developed rapidly in areas such as intelligent machine design and cutting-edge applications.The Marangoni effect is one of the driving schemes of stimuli-responsive actuators in liquid environment.According to the different inducing methods of Marangoni effect,it can be divided into thermal,photothermal and solutes Marangoni effect.Thermal and photothermal Marangoni effects are mainly caused by temperature gradient,while solutes Marangoni effect is caused by solutes concentration gradient or chemical reaction.Based on the advantages of Marangoni effect in controllability,multiple control modes and motion performance,which makes the Marangoni actuator have broad application potential.Therefore,the further development of Marangoni actuators has important research value and significance.Through the systematic research on the development history,preparation method,driving strategy and practical application of Marangoni actuator,we find that the Marangoni actuator still faces the following problems: 1.The photothermal Marangoni actuator is the most common,but how to integrate photothermal conversion materials with devices of arbitrary shape and material is still a difficult problem,which limits the Marangoni effect applied to most objects.2.The Marangoni effect based on different induction methods can form complementary advantages.However,there are few reports on the Marangoni actuator that can be controlled by Multi-field coupled including a variety of Marangoni effects,which makes Marangoni actuators have defects in manipulation.3.At present,the most researches of Marangoni actuator focus on the exploration of the principle of motion,and there are few actuators that can be really expanded for application,so we still need more practical Marangoni actuator designed for application scenarios.Therefore,in view of the limitation of Marangoni actuator in many aspects,we combined a variety of design schemes,preparation methods and material selection to study Marangoni actuator from three aspects of design & preparation,manipulation and practical application.That is,1.Design and preparation of integrated Marangoni actuator.2.Multi-field coupled manipulation of Marangoni actuator.3.Preparation and research of drug loading Marangoni actuator.The main achievements are as follows:1.In the aspect of design and preparation,the integrated Marangoni actuator is prepared,which makes the Marangoni effect extend to most substrates.An integrated photothermal Marangoni effect actuator was fabricated using Laser Induced Graphene(LIG)tape.Graphene can be directly patterned on polyimide tape by laser direct writing technology.Polyimide tape can be pasted on most objects to form a simple integrated actuator.The structure of LIG has good photothermal conversion characteristics,which leads to non-uniform temperature distribution of the actuator under illumination,and this non-uniform temperature gradient field produces Marangoni effect.According to this principle,two-dimensional patterned floating film actuator,integrated blade actuator and three-dimensional flexible origami actuator were designed and prepared,which demonstrated the flexible patterning ability of laser processing.Through the proliferation experiment of human breast cancer cell MDA-MB-231,the good biocompatibility of Marangoni actuator based on LIG tape was verified.And realized the application of Marangoni actuator in the medium: remote control of the actuator to realize the stirring of the medium.2.In the aspect of manipulation,the multi-field coupled manipulation of Marangoni actuator is realized,which makes the two Marangoni effects complement each other in the movement duration and start-up time of the actuator.The Marangoni actuator based on graphene porous membrane was prepared by vacuum freeze-drying method.By adding sodium dodecyl sulfate(SDS)into the porous membrane as "fuel",the reduced graphene oxide(RGO)porous membrane was prepared by laser processing method as a photothermal material.Combining the solutes and photothermal Marangoni effect realized the complementary advantages.This study successfully verified the rotating motion of the porous graphene membrane actuator driven by the solute Marangoni effect.At the same time,it also successfully verified that the actuator can realize the rotation and linear motion driven by the photothermal Marangoni effect under the incandescent lamp or laser,which shows the diversification and flexibility of the motion mode generated by the Marangoni effect.Furthermore,by introducing magnetic nanoparticles in the preparation of the actuator,we developed a magnetic field assisted manipulation Marangoni actuator,which expanded the control means and potential application scenarios.The graphene porous membrane actuator has good stability without external force damage,and also has the ability of dissolving and preparing new actuator.3.In the aspect of practical application,the design and preparation of Marangoni actuator for practical application are realized.The drug loading Marangoni actuator is successfully developed.Chitosan and Eudragit UDRAGIT were used as the main body and functional layer of the actuator respectively,hexafluoroisopropanol(HFIP)and plant carbon black were wrapped in Eudragit layer as functional materials,which made the actuator have the ability to drive by solutes and photothermal Marangoni effects.It is the first time to couple the stimuli-responsive deformation with the Marangoni effect to drive the actuator.Under the stimulation of the water,the deformation mismatch between the chitosan layer and the Eudragit layer occurs,which makes the actuator deform from a two-dimensional plane to a three-dimensional structure to achieve drag reduction effect,showing the excellent deformation ability of the stimuli-responsive materials.Experiments in vivo and in vitro prove that Marangoni actuator has good biological safety.Finally,the Marangoni actuator successfully carried and released the drug DOX.