温度驱动飞秒激光打印微结构的可逆自组装  

Reversible Self⁃Assembly of Temperature⁃Driven Femtosecond Laser Printed Microstructures

作　　者：倪才鼎 劳召欣 任中国 陈超 吴东 Ni Caiding;Lao Zhaoxin;Ren Zhongguo;Chen Chao;Wu Dong(School of Engineering Science,University of Science and Technology of China,Hefei 230026,Anhui,China;Anhui Province Key Laboratory of Measuring Theory and Precision Instrument,School of Instrument Science and Optoelectronic Engineering,Hefei University of Technology,Hefei 230009,Anhui,China;Department of Materials Physics and New Energy Device,School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,Anhui,China)

机构地区：[1]中国科学技术大学工程科学学院,安徽合肥230026 [2]合肥工业大学仪器科学与光电工程学院测量理论与精密仪器安徽省重点实验室,安徽合肥230009 [3]合肥工业大学材料科学与工程学院材料物理及新能源材料与器件系,安徽合肥230009

出　　处：《中国激光》2023年第20期169-176,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(61927814,52175396);合肥工业大学中央高校科研经费(JZ2022HGPA0312)。

摘　　要：模板引导的毛细力驱动自组装技术逐渐被认为是制造一系列微纳米结构的一种替代方法。毛细力自组装微结构的稳定性取决于结构接触力和支撑力的竞争,接触面积越大,接触力越大。当接触面积大于临界值时,微结构的组装行为不可逆。利用飞秒激光打印具有各向异性的微结构,在不同温度的调控下实现其多方向运动,并借助温度响应水凝胶的反向变形能力,实现了线接触微结构的可逆自组装。此外还探究了该方法在微执行器、微传感器方向的应用。结果表明,通过改变环境的温度能够实现微结构的弯曲变形,且利用飞秒激光双光子加工的灵活性和毛细力驱动的简便性,可以实现可逆变形的微图案以及功能丰富的微传感结构。Objective Template-guided capillary force-driven self-assembly technology is increasingly being considered as an alternative for fabricating a range of micro/nanostructures.Because of the advantages of rapid preparation of large-area and controllable complex hierarchical microstructures,the combination of femtosecond laser and capillary force-driven assembly(LPCS)technology has become an attractive method.In the LPCS method,the stability of the microstructure depends on the competition between the contact force,e.g.,the van der Waals force,and elastic force of the microstructure after self-assembly.The contact force between microstructures is positively correlated with the contact area of the microstructure.A larger contact area corresponds to the larger van der Waals force and more stable assembly.When the contact area is greater than the critical value,the microstructure assembly behavior is irreversible.In our previous research,we found that microstructures with linear contact,such as microwalls,or even microstructures with surface contact could not be restored to the upright state after immersion in a liquid because of the large contact area after assembly,which greatly limits the application range of microstructures.In this study,the reversible self-assembly of linear contact microstructures prepared by LPCS is realized by taking advantage of the significant deformation ability of temperature-responsive hydrogels.Methods In this study,the temperature-responsive hydrogel is mainly composed of N-isopropylacrylamide,acrylamide,and phosphine oxide,where N-isopropylacrylamide is the monomer,acrylamide is the crosslinking agent,and phosphine oxide is the photoinitiator.We successively put the 400 mg N-isopropylacrylamide,30 mg acrylamide,30 mg phosphine oxide,and 450μL glycol into a bottle and then place the bottle in a water bath at 50℃for ultrasound.Finally,the 50 mg polyethylene pyrrolidone is added as a viscosifier.The femtosecond laser source used in the experiment has a pulse width of 75 fs,repetition fre

关 键 词：激光技术 飞秒激光 双光子聚合 毛细力 自组装 温度响应 

分 类 号：O436[机械工程—光学工程]