Department of Electrical and Computer Engineering, College of Engineering, Texas A&M University, College Station, TX 77843-3128, USA.
Biomed Microdevices. 2010 Apr;12(2):345-51. doi: 10.1007/s10544-009-9390-9.
We present a novel micro-macro hybrid soft-lithography master (MMHSM) fabrication technique where microdevices having both microscale and macroscale features can be replicated with a single soft-lithography step. A poly(methyl methacrylate) (PMMA) master having macroscale structures was first created by a bench-top milling machine. An imprinting master mold having microscale structures was then imprinted on the PMMA surface through a hot-embossing process to obtain a PMMA master mold. A poly(dimethylsiloxane) (PDMS) master was then replicated from this PMMA master through a standard soft-lithography process. This process allowed both microscale (height: 3-20 microm, width: 20-500 microm) and macroscale (height: 3.5 mm, width: 1.2-7 mm) structures to co-exist on the PDMS master mold, from which final PDMS devices could be easily stamped out in large quantities. Microfluidic structures requiring macroscale dimensions in height, such as reservoirs or fluidic tubing interconnects, could be directly built into PDMS microfluidic devices without the typically used manual punching process. This significantly reduced alignment errors and time required for such manual fabrication steps. In this paper, we successfully demonstrated the utility of this novel hybrid fabrication method by fabricating a PDMS microfluidic device with 40 built-in fluidic interfaces and a PDMS multi-compartment neuron co-culture platform, where millimeter-scale compartments are connected via arrays of 20 microm wide and 200 microm long microfluidic channels. The resulting structures were characterized for the integrity of the transferred pattern sizes and the surface roughness using scanning electron microscopy and optical profilometry.
我们提出了一种新颖的微-宏观混合软光刻母版（MMHSM）制造技术，通过单次软光刻步骤即可复制具有微尺度和宏观尺度特征的微器件。首先使用台式铣床制作具有宏观结构的聚甲基丙烯酸甲酯（PMMA）母版。然后通过热压印工艺在 PMMA 表面压印具有微结构的压印母模，以获得 PMMA 母模。然后通过标准的软光刻工艺从该 PMMA 母版复制出 PDMS 母版。该工艺允许 PDMS 母版上同时存在微尺度（高度：3-20 微米，宽度：20-500 微米）和宏观结构（高度：3.5 毫米，宽度：1.2-7 毫米），可以从最终的 PDMS 模具中大量轻松冲压出器件。需要宏观尺寸高度的微流控结构，例如储液器或流体管道互连，可以直接构建到 PDMS 微流控器件中，而无需通常使用的手动打孔工艺。这大大减少了此类手动制造步骤的对准误差和所需时间。在本文中，我们通过制造具有 40 个内置流道接口的 PDMS 微流控器件和 PDMS 多腔神经元共培养平台，成功地证明了这种新颖的混合制造方法的实用性，其中毫米级别的腔室通过 20 微米宽和 200 微米长的微流道阵列连接。使用扫描电子显微镜和光学轮廓仪对所得结构进行了转移图案尺寸完整性和表面粗糙度的特征分析。
