Wu Hongkai, Huang Bo, Zare Richard N
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
Lab Chip. 2005 Dec;5(12):1393-8. doi: 10.1039/b510494g. Epub 2005 Oct 17.
A thin layer of polydimethylsiloxane (PDMS) prepolymer, which is coated on a glass slide, is transferred onto the embossed area surfaces of a patterned substrate. This coated substrate is brought into contact with a flat plate, and the two structures are permanently bonded to form a sealed fluidic system by thermocuring (60 degrees C for 30 min) the prepolymer. The PDMS exists only at the contact area of the two surfaces with a negligible portion exposed to the microfluidic channel. This method is demonstrated by bonding microfluidic channels of two representative soft materials (PDMS substrate on a PDMS plate), and two representative hard materials (glass substrate on a glass plate). The effects of the adhesive layer on the electroosmotic flow (EOF) in glass channels are calculated and compared with the experimental results of a CE separation. For a channel with a size of approximately 10 to 500 microm, a approximately 200-500 nm thick adhesive layer creates a bond without voids or excess material and has little effect on the EOF rate. The major advantages of this bonding method are its generality and its ease of use.
涂覆在载玻片上的一层薄聚二甲基硅氧烷（PDMS）预聚物被转移到图案化基底的压纹区域表面上。将该涂覆的基底与平板接触，并通过对预聚物进行热固化（60℃，30分钟）使这两个结构永久结合以形成密封的流体系统。PDMS仅存在于两个表面的接触区域，暴露于微流体通道的部分可忽略不计。通过将两种代表性软材料（PDMS板上的PDMS基底）和两种代表性硬材料（玻璃板上的玻璃基底）的微流体通道进行结合来证明该方法。计算了粘合剂层对玻璃通道中电渗流（EOF）的影响，并与CE分离的实验结果进行了比较。对于尺寸约为10至500微米的通道，约200 - 500纳米厚的粘合剂层可形成无空隙或多余材料的结合，并且对EOF速率影响很小。这种结合方法的主要优点是其通用性和易用性。
