一种新的纸基微流开关及其活跃方法

A New Paper-Based Microfluidic Switch and Its Activating Method

提出了一种新的、基于声表面波的纸基微流开关。通过软光刻技术制作内含两个微孔的聚二甲基硅氧烷(PDMS)微架,其上固定经折叠、长度可变的纸通道。PDMS微架贴附于压电基片之上,并在待连接的两微通道之下方,折叠纸通道最低端离压电基片间距为2 mm。压电基片上采用微电子工艺光刻一对叉指换能器和反射栅。当足够强度的电信号加到叉指换能器对时,激发两相向声表面波,使得压电基片上微流体输运到折叠纸通道,改变其长度,连接其上待连通的两纸基微通道,完成开关功能。对可编程微流器件提供了一种新的编程和开关控制方法。

A new paper-based microfluidic switch based on surface acoustic wave has been presented.A poly dimethylsilicoxane（PDMS）micro-shelf with two micro-holes was fabricated at first using soft photoetching technology.A folded paper channel with variable length was then fixed on the PDMS micro-shelf,which mounted on a piezoelectric substrate ensuring 2 mm space to the lowest end of the folded paper channel.Two microchannels to be connected were stuck above the folded paper channel.A pair of interdigital transducers（IDTs）together with two reflectors was fabricated on the（XY）/128° LiNbO3 piezoelectric substrate using micro-electric technology.When a RF signal with appropriate power was applied to the IDTs,two surface acoustic waves（SAWs）were generated.A microfluid on the piezoelectric substrate was transported to the folded paper channel due to acoustic streaming.The length of folded paper channel was then enlarged so that it could connect two paper-based microchannels waiting for connection.Thus,the function of the switch was implemented.The presented microfluidic switch and its activating method are helpful to research programmable microfluidic devices.