Li Qiang, Jiang Bingyan, Li Xianglin, Zhou Mingyong
College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
State Key Laboratory of High performance Complex Manufacturing, Central South University, Changsha 410083, China.
Micromachines (Basel). 2022 Jun 18;13(6):965. doi: 10.3390/mi13060965.
The bonding of microfluidic chips is an essential process to enclose microchannels or microchambers in a lab-on-a-chip. In order to improve the bonding quality while reducing the fabrication time, a solvent-assisted bonding strategy was proposed to seal the microchannels immediately after the cover sheet and substrate chip was injection molded in a single mold. Proper organic solvents were selected and the influences of solvent ratios on the surface roughness, microchannel morphology, and contact angle of microfluidic chips were investigated. When the solvent bonding was integrated in the mold, the influences of solvent volume fraction, solvent dosage, bonding pressure, and bonding time on the bonding quality were analyzed. Results show that the solvent cyclohexane needs to be mixed with isopropanol to reduce the dissolution effect. Solvent treatment is suggested to be performed on the cover sheet with a cyclohexane volume fraction of 70% and a dose of 1.5 mL, a bonding pressure of 2 MPa, and a bonding time of 240 s. The bonding strength reaches 913 kPa with the optimized parameters, while the microchannel deformation was controlled below 8%.
微流控芯片的键合是在芯片实验室中封闭微通道或微腔的关键工艺。为了在缩短制造时间的同时提高键合质量，提出了一种溶剂辅助键合策略，即在盖板和基片芯片在单个模具中注塑成型后立即密封微通道。选择了合适的有机溶剂，并研究了溶剂比例对微流控芯片表面粗糙度、微通道形态和接触角的影响。当溶剂键合集成到模具中时，分析了溶剂体积分数、溶剂量、键合压力和键合时间对键合质量的影响。结果表明，需要将环己烷与异丙醇混合以降低溶解效果。建议对盖板进行溶剂处理，环己烷体积分数为70%，剂量为1.5 mL，键合压力为2 MPa，键合时间为240 s。优化参数后键合强度达到913 kPa，同时微通道变形控制在8%以下。
