Femtosecond Laser Direct Writing Of Micro/Nano Structures And Devices Based On Protein Biomaterials

Protein is the most important natural material with a huge amount in the world.And protein is being used in more and more fields.Compared with artificial sunthetic polymer materials,protein materials have many good qualities,such as good biocompatibility,good biological degradation,having charging active sites for biochemical modification,and easy to be processed using a variety of micro/nano processing technologies,all of these good qualities are beneficial for protein applicated in cutting-edge cross innovation fields such as biomedicine.The mainly micro/nano processing technologies for proteins,there are microimprint technology,UV lithography,electrospinning,electron beam etching,microinjection,femtosecond laser direct writing,and so on.Among them,femtosecond laser direct writing technology has nano-level high processing accuracy,very low additional damage to protein materials,maskless and non-contact,and true three-dimsional processing capabilities and other advantages.These make the femtosecond laser direct writing technology being better applied to mocro/nano processing of protein materials,avoid introducing bacterial and other impurities,and even in situ processing of protein micro/nano structures could be performed near living cells.In the work of this thesis,for the first time we fabricate the micro/nano-structures of sericin and sericin-silver composites using femtosecond laser direct writing technology,and study its related properties.And we fabricate Y-junction power splitter micro-optical device based on bovine serum albumin using femtosecond laser direct writing technology,and realize its detection response to changes in th pH of the environment.The main contents include:1.Fabricate two-dimensional and three-dimensional microstructures of sericin using femtosecond laser direct writing technology.Febricate two-dimensional microstructures of sericin and silver composites,and achieve efficient biomineralization of silver ions by sericin using femtosecond lasers.2.Characcterize and study the related physical and chemical properties of two-dimensional microstructure of sericin fabricated by femtosecond laser direct writing.The characterization of the mechanical properties indicating,the sericin microstructure prepared by femtosecond laser direct writing has a high Young's modulus,up to 3.35 GPa.Using the two-dimensional microstructure of sericin and the twomicrostructure of the sericin and silver composite culture the cells biologically,and the microstructures designed and fabricated have a certain degree effects on the growth of cells.3.Fabricate Y-junctin power splitter micro-optical device based on bovine serum albumin by femtosecond laser direct writing.The highly-designed micromachining capability of femtosecond lasers,achieves two different optical splitting capabilities for micro-devices in the air: ~1:1 and ~3:1 for incident light.And through the adjustment of one proessing parameter of the femtosecond laser when processing one branch of the Y-junction type power splitter micro-optical device,enables the device to detect the changes in the pH of the environment.When the pH in the solution environment changes from 2.0 to 6.0,the split ratio of the two branches of the Y-junction type power splitter micro-optical device varies from ~1.48:1 to ~1.85:1,and it is a reversible process of the change.In this paper,we realize the processing of sericin proteins using femtosecond laser direct writing.And study the relevant properties of the fabricated microstructures.And fabricate protein-based Y-junction splitter micro-optical devices.Take advantage of the property of protein side chain amono acids carrying charge and the excellent microprocessing capability of the femtosecond laser direct writing technology,enabling the device to detect the changes in the pH of the environment.This article can helps to promote the researching on sericin proteins using micro-processing techniques such as femtosecond lasers,and on the protein-based micro-optical devices with environmental monitoring capabilities.