Yetisen Ali K, Soylemezoglu Bugra, Dong Jie, Montelongo Yunuen, Butt Haider, Jakobi Martin, Koch Alexander W
Institute for Measurement Systems and Sensor Technology, Technical University of Munich 80333 Munich Germany
School of Civil, Mechanical and Industrial Engineering, Universidad De La Salle Bajío León 37150 Mexico.
RSC Adv. 2019 Apr 9;9(20):11186-11193. doi: 10.1039/c9ra01094g.
Continuous monitoring of biomarkers in a quantitative manner at point-of-care settings can advance early diagnosis in medicine. Contact lenses offer a minimally-invasive platform to continuously detect biomarkers in tear fluid. Microfluidic components as lab-on-a-chip technology have the potential to transform contact lenses into fully-integrated multiplexed sensing devices. Here, simple and complex microchannels are created in scleral lenses that perform microfluidic operations capillary action. The engraving of microchannels in scleral lenses were performed by laser micromilling, where a predictive computational model was developed to simulate the effect of laser power and exposure time on polymer behavior. Experimentally varying the CO laser power (1.2-3.6 W) and speed (38-100 mm s) allowed the micromilling of concave microchannels with groove depths of 10-240 μm and widths of 35-245 μm on polymetric substrates. The demonstrated laser micromilled circuitry in scleral lenses included linear channels, T/Y junctions, multiplexed arrays, mixers, and spiral channels, as well as serially organized multicomponent channels. Capillary forces acting in the microchannels allowed flowing rhodamine dye within the microfluidic components, which was visualized by optical microscopy in reflection and transmission modes simultaneously. The developed microfluidic components in scleral lenses may enable tear sampling, storage, analysis, and multiplexed detection capabilities for continuous monitoring applications.
在即时护理环境中以定量方式持续监测生物标志物可以推动医学的早期诊断。隐形眼镜提供了一个微创平台，用于持续检测泪液中的生物标志物。作为芯片实验室技术的微流体组件有潜力将隐形眼镜转变为完全集成的多重传感设备。在此，在巩膜镜中创建了简单和复杂的微通道，这些微通道通过毛细作用执行微流体操作。巩膜镜中微通道的雕刻通过激光微铣进行，其中开发了一个预测计算模型来模拟激光功率和曝光时间对聚合物行为的影响。通过实验改变CO激光功率（1.2 - 3.6 W）和速度（38 - 100 mm/s），可以在聚合物基板上微铣出凹槽深度为10 - 240μm、宽度为35 - 245μm的凹形微通道。在巩膜镜中展示的激光微铣电路包括线性通道、T/Y形接头、多重阵列、混合器和螺旋通道，以及串联组织的多组分通道。作用于微通道的毛细力使罗丹明染料在微流体组件内流动，可通过光学显微镜在反射和透射模式下同时观察到。在巩膜镜中开发的微流体组件可能实现用于连续监测应用的泪液采样、储存、分析和多重检测能力。
