Stoneman Michael, Fox Michael, Zeng Chaoyang, Raicu Valerică
Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, USA.
Lab Chip. 2009 Mar 21;9(6):819-27. doi: 10.1039/b816993d. Epub 2008 Dec 4.
We report an improved method for production of microfluidic device masters using two-photon photopolymerization of SU-8 negative photoresist, which relies on a two-photon microscope (TPM) commonly used in imaging of biological samples. The device masters serve as negative relief structures for polydimethylsiloxane-based microfluidic devices. We observed that not only did the two-photon excitation of the SU-8 photoresist initiate crosslinking of the material in the region of the focus of the near-infrared laser beam (as expected) but it also resulted in emission of fluorescence in the visible range. The detected emission of SU-8 photoresist undergoing two-photon excitation displayed a strong correlation with the size of the polymerized objects produced during the exposure; this allowed the progress of the microfluidic master production process to be monitored in real-time. We demonstrate the use of the fluorescence detection during two-photon photopolymerization in the production of microfluidic devices, which were designed to trap individual yeast cells to be imaged with the same TPM used for microfluidic master writing.
我们报告了一种改进的方法，用于使用SU-8负性光刻胶的双光子光聚合来生产微流控器件母版，该方法依赖于常用于生物样品成像的双光子显微镜（TPM）。这些器件母版用作基于聚二甲基硅氧烷的微流控器件的负性浮雕结构。我们观察到，SU-8光刻胶的双光子激发不仅（如预期的那样）在近红外激光束焦点区域引发了材料的交联，还导致了可见光范围内的荧光发射。检测到的经历双光子激发的SU-8光刻胶的发射与曝光过程中产生的聚合物体的尺寸显示出强烈的相关性；这使得能够实时监测微流控母版生产过程的进展。我们展示了在微流控器件生产过程中双光子光聚合期间荧光检测的应用，这些微流控器件旨在捕获单个酵母细胞，以便用用于微流控母版写入的同一台TPM进行成像。
