Simultaneously improving fabrication accuracy and interfacial bonding strength of multi-material projection stereolithography by multi-step exposure  

作　　者：Xinghong Deng Guangyu Zhang Yi Mo Zhiyuan Huang Dekai Zhou Jing Qiao Longqiu Li 

机构地区：[1]State Key Laboratory of Robotics and System,Harbin Institute of Technology,Harbin,China [2]School of Materials Science and Engineering,Harbin Institute of Technology,Harbin,China

出　　处：《International Journal of Smart and Nano Materials》2024年第2期387-404,共18页国际智能和纳米材料杂志（英文）

基　　金：supported by the National Key Research and Development Program of China [2022YFB4600102];National Natural Science Foundation of China [52125505,U20A20297,52275561,U23A20637].

摘　　要：Multi-material additive manufacturing(MMAM)takes full advantage of the ability to arbitrarily place materials of addi-tive manufacturing technology,enabling immense design free-dom and functional print capabilities.Among MMAM technologies,projection stereolithography(PSL)exhibits a great balance of high resolution and fast printing speed.However,fabrication accuracy of multi-material PSL is hin-dered by large overcure used to strengthen interfacial bond-ing weakened by chemical affinity and material-exchange process.We present a novel multi-step exposure method for multi-material PSL process to overcome this shortcoming.Firstly,the whole layer is moderately exposed producing over-cure of single-material PSL level to generate geometries.Then weakened interfaces are strengthened individually with addi-tional steps of exposure.The multi-step exposure is integrated into the already efficient materials printing order of multi-material PSL process.Curing depth and overcure of photocur-able resins are modeled and characterized.Exposure required to achieve sufficient interfacial bonding of single-material interfaces built through material-exchange process and multi-material interfaces with altering materials printing order is determined with tensile tests.Microfluidic channels are used to compare fabrication accuracy of traditional single-step exposure and our multi-step exposure method.This method can be widely applied in multi-material PSL to improve fabri-cation accuracy in a variety of applications including micro-fluidic devices.

关 键 词：Additive manufacturing multi-material projection stereolithography multi-step exposure interfacial bonding 

分 类 号：TB30[一般工业技术—材料科学与工程]