Study On 3D AMF Model Process Technology In Two-photon Polymerization By Femtosecond Laser

Two-Photon Polymerization by Femtosecond Laser is a technology which integrates the CAD and CAM technology to fabricate three-dimensional micro-nano structures.This technology can break through the limit of light diffraction limit to manufacture microstructure of which feature size is less than 100 nm,and also can realize the fabrication of arbitrary complex three-dimensional micro-nano structure/device.So far,it has been applied in the preparation of Micro-optics element,Micro-electro-mechanical systems,microfluidics,Metamaterials,biomedical devices and so on.3D data models as the basis of the TPP,is the premise and foundation to realize TPP manufacturing.The 3D structure model of TPP no matter comes from forward modeling design or reverse engineering reconstruction all need to process considering the specific requirements of TPP process and the constraints of existing machining system to meet the needs of the TPP processing.So the Data processing of 3D model is one of the core technology of TPP,and it's the data base and premise to get micro-nano structure accurately and efficiently.With the demand of large-area 3D micro/nanostructures repaid fabrication,3D scanning system based on long-travel air bearing stage and two-dimensional galvanometer is gradually used,this requires corresponding data interface to fit the system.So in this paper,AMF model,AMF Slicing Methods,Section contour fitting of slice and Scanning path of laser are studied.The achievements in this paper are as follows:(1)In order to realize a geometry description with suitable data storage of complex three-dimensional micro/nano structure comprehensively and accurately.This paper uses a new file format—AMF(Additive Manufacturing File Format)to realize geometric expression of three-dimensional structure.By analyzing data structure,model precision and data storage of AMF file,a subdivision algorithm based on curved triangles in AMF model is proposed and an example is proposed to verify the algorithm,the result shows that the subdivision algorithm can effectively improve the surface precision of a given AMF model.(2)A slicing algorithm based on edge information sort of triangles in AMF model has been put forward.According to the structural characteristics of AMF,removing all redundant edges of triangles in AMF file;Establishing the topological relationship between the rest of each edge and the two adjacent triangles,and sorting all edges according left value of each edge;Using a series of plane thatiZ(28)zto intersect with some edges to get intersection to obtain section contour of slice.Examples are proposed to verify the method,and the result shows that the method is feasible and stable without redundant data,and it is also effective even if it cannot ensure the validity of AMF file.(3)In order to guarantee the dimensional accuracy and shape accuracy of the entity,this paper deals with cross section contour of slices by using spline curve contour and grating type scanning by continuous scanning method.Section contour data fitting and laser scanning path generating are respectively studied: Firstly,sectioning section contour of each slice,and fitting the cross section contour of each slice with subsection NURBS curve;Secondly,using raster scanning method to fill every slice section;Lastly,in order to convenient checking,controlling and tracking data processing,a data processing system of the AMF model of TPP based on Matlab is established.Examples are proposed to verify the method to deal with slices and the system,and the result shows that they are feasible.