| Two-Photon Polymerization manufacture technology is to use ultra-fast short pulse laser to induce material polymerization and form expecting structure.It possesses super high manufacture precision and real three-dimensional manufacture capacity.Three-dimensional micro/nano functional device produced with this technology has been widely applied in aeronautical,space technologies,military,information science,tissue engineering,biomedical and many other fields.However,since TPP manufacture always accompanies with solid-liquid structure conversion,uneven shrinkage of the produced structure of the materials becomes a major barrier to obtain high quality three-dimensional micro/nano structure.Therefore,it is very important to study the shrinkage characteristics and compensation methods of two-photon polymerization micro/nano structures.In this paper,we studied micro/nano structure shrinkage mechanism,uneven shrinkage,structure compensation and even preparation aspects for uneven contraction of three-dimensional micro/nano structure during production.The major study content are as follows:?1?Based on our group established large-scaling two-photon polymerization rapid manufacturing system,the cube structure is processed by the two-photon polymerization processing technology,analyzing the effect of the laser power,exposure time,post baking process,developing process,hardbaking process,and structure height on the structure produced.Based on the principle of least square,by using regression analysis of statistical methods,shrinkage model to compensate the structural shrinkage was established.?2?Based on the principle of Newtonian mechanics,by using molecular kinetics software,polymerization structure and SiO2 substrate molecular interface model was established.Its molecular structure was put into a cubic box with a periodic border condition.By implementing COMPASS gravity field,using Smart algorithm analyze the least energy to mimic the molecule,the molecular interface structure reached to a stable status.Under NVT canonical ensemble,according to the simulation of the interface molecule kinetics,the energy of each portion of the interface model was obtained,and the uneven shrinkage of macro structure was analyzed.Based on the molecular kinetics static method,according to analyzation of the mechanical properties of the molecule model system of micro/nano structures,mechanical elastic parameters of the polymer structure was obtained,which accord with the material properties.This suggests the molecular model established is reasonable.?3?By controlling the relationship between the voxels and substrate,we established a method to decrease the adhesive force between the preparation structure and substrate,a novel preparation of the woodpile structure homogenization was accomplished.By using shrinkage compensate model to design a compensate model,obtained CAD model,we studied woodpile structure shrinkage property.The experiment validated the homogenization of the prepared woodpile structure. |
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