Research On Laser-induced Controllable Micro-nano Structures And Their Regulation On Interface Properties

Interface regulation has very important application prospects in our life,which has attracted the interest of researchers.For example,structural colors can be used for identification codes,decorative beautification,and anti-counterfeiting.Superhydrophobic and low-adhesion surfaces can be used for antifouling,anti-icing,and self-cleaning.Self-propulsion based on surface tension gradients can be used in robotics and power generation.These unique interface phenomena are essentially caused by the regulation of interface physical properties by micro-nano structures,and the processing of controllable micro-nano structures has become a research hotspot.Although a variety of micro-nano structures have been successfully fabricated by some micro-nano processing techniques,and have been used for interface regulation.However,there are still some problems in the efficient preparation of large-area micronano structures,the application range of interface regulation,and the precise regulation of interface physical properties.In this paper,we solve the above problems by different laser micro-nano processing techniques.The main contents include:1.Large-area metal microgroove arrays are fabricated on various metal surfaces in one step through focused laser interference processing system.A 1×1 mm2 area can be processed in a single exposure,which is 2.5 times more efficient than the existing single-point scanning technology.The forming mechanism of the metal microgroove arrays is analyzed in details,and the morphology of the metal microgroove arrays can be controlled by processing parameters.The regulation of structural color by the morphology of metal microgroove arrays is quantitatively studied.In addition,the regulation of anisotropic wettability by metal microgroove arrays with different morphologies is explored.2.A method for regulation of adhesion to liquid metal by rough micro-nano structures is proposed.Femtosecond laser ablation processing system is used to induce rough micro-nano structures on the polymer surface,and the regulation of adhesion to liquid metal is realized.And the regulation mechanism is clarified,thereby expanding the application scope of wettability and adhesion regulation.By changing the morphology of rough micro-nano structures by processing parameters,precise regulation of adhesion to liquid metal is achieved.And through further transfer,the patterning of the liquid metal is realized.Its application in the field of flexible electronic devices is explored.3.A method for regulation of the surface tension distribution by porous micronano structures is proposed.Laser maskless grayscale lithography processing system is used to realize the controllable fabrication of the asymmetric porous micro-nano structures in the hydrogel.The model between the release rate of low surface tension organic liquid and the porous micro-nano structures is built.A hydrogel rotor is further fabricated,and the release rate of organic liquid is controlled by the asymmetric porous micro-nano structures in different parts of the rotor.The surface tension distribution around the rotor is precisely regulated to enhance the asymmetric surface tension gradient,and the high-speed self-propulsion of the rotor is realized.In order to further improve the self-propulsion performance of the hydrogel rotor,a rotor shape with drag reduction effect is designed based on theoretical models and experiments.The maximum rotation speed of the hydrogel rotor reaches 5215 rpm.Furthermore,the hydrogel rotor precedes previous studies in rotation output(-15 times)and fuel economy(-34%higher).Finally,the applications of self-propelled hydrogel rotor in kinetic energy transmission,power generation,and water purification are demonstrated.