Study On The Method Of Manufacturing Microstructures By Meniscus Confined Electrodeposition

Meniscus Confined Electrodeposition（MCED）micro and nano additive manufacturing methods,as a complement to traditional microfabrication methods,have important applications in the fields of photonics,microelectronics,biotechnology and biomedicine,and metamaterials.However,there are still many challenges for the stable fabrication of complex3D microstructures with large scale and high aspect ratio based on glass microprobe droplet-limited electrodeposition fabrication methods.This paper improves and optimizes the existing experimental platform for micro and nano fabrication,develops a leveling platform with flexible hinge structure and proposes a new theta-type probe electrodeposition model and its feedback control method.The method enhances the stability and reliability of MCED,which in turn enables the development of cilia-based micro-flux sensors by preparing a large-scale,high-aspect-ratio array of micro-pillar structures on the improved experimental platform.The main research work of the paper is as follows:First,the existing experimental stages were improved and optimized in order to realize the deposition experiments of microstructure arrays with large scale and high aspect ratio.The motion stroke of the coarse displacement stage is expanded from 15 mm?15 mm to 60 mm?60 mm,and the motion stroke of the precision displacement stage is expanded from 80μm?80μm to 200μm?200μm.In turn,it can be adapted to a larger range of microstructure fabrication.At the same time,in order to visualize the deposition process and reduce the complexity of experimental operations,the system is equipped with additional hardware such as cameras and optical components to realize the visualization function.The visualization function and motion performance of the motion platform were then tested.The experimental results showed that the improved and optimized experimental platform achieved real-time observation of microdroplets at the probe tip.The fabrication of microstructures with height greater than 100μm was achieved,and the variance of the average height of the scanned sample cutoff is less than 0.5μm²,which laid a good foundation for the fabrication of glass microprobe droplet-limited electrodeposition microstructures at a later stage.Second,in order to solve the problem of increasing the contact area between microdroplets and substrate caused by uneven substrate,which in turn leads to larger diameter of deposited structure and tilting of deposited structure.The paper firstly designs a flexible hinge structure tuning platform based on the four-point tuning principle by comparing the advantages and disadvantages of the tuning scheme principles.The key parameters of the leveling platform were then optimized using the response surface optimization method in the finite element analysis tool.The simulation results show that the designed leveling platform can achieve the rotation of two orthogonal axes±0.73°and meet the performance indexes required by the later experiments.Next,in order to solve the problems of unstable deposition current and consequently poor uniformity of the diameter of the deposited structures in the traditional control method using constant voltage deposition,the fabrication of large-scale,high aspect ratio micro-pillar structures is not possible.The paper proposes a new theta-type probe electrodeposition model and its feedback control method.The method starts with circuit modeling of the glass microprobe droplet-limited electrodeposition method and analyzes the causes of its current fluctuation.And based on it,using finite element analysis tools,the correctness of the model is verified,and then a feedback control method based on a constant deposition current is proposed.The method maintains a stable deposition current by adjusting the voltage between the two electrodes in the theta tube in real time.The final experimental results show that the standard deviation of the deposition current is reduced from 7.79?10^-4 n A for the conventional constant voltage control to 1.33?10^-4 n A,and the diameter variance of the fabricated micro-pillar structure is reduced from 0.145μm² to 0.056μm².Finally,the cilia-based micro-flow sensor with piezoresistive cantilever beam structure was developed using the above improved MCED micro-nano fabrication method.The key parameters such as the optimal cilia diameter,cilia height,cilia array size and cantilever beam length were firstly determined by using COMSOL finite element analysis method.Then,the micro-flow sensor was prepared according to the parameters derived from the simulation analysis and the sensor was tested.It is proved that the developed cilia micro flow sensor can sense the flow rate from 0.1 m/s to 2 m/s,and the nonlinear error of the sensor is 2.84%when the flow rate is greater than 0.4 m/s.In summary,the thesis lays the foundation for the later large-scale,high-aspect-ratio additive manufacturing of complex microstructures by optimizing and improving the experimental platform and designing a flexible hinge structure tuning platform.At the same time,the thesis proposes a new theta-type probe electrodeposition model and its feedback control method to achieve stable deposition of large-scale,high-aspect-ratio microstructures.Finally,the proposed method was used to realize the development of micro-flow sensors.The research results demonstrate the effectiveness of the MCED method in the fabrication of large-scale and high-aspect-ratio microstructures,which will be widely used in the field of micro and nano fabrication in the future.