压电基片上集成微通道数字微流体微混合器研究

微流体在压电基片上输运往往偏离声表面波传播方向,尤其是当压电基片表面疏水层不很均匀时,给微流体诸如混合等操作带来不便。在1280旋转Y切割X传播方向的LiNbO3基片上研制了集成有聚二甲基硅氧烷为材料T型微通道的微混合器,压电基片上采用光刻工艺制作相互垂直叉指换能器及反射栅。待混合的两微流体采用微量进样器分别进样到声路径微通道中,依次在两叉指换能器上加RF电信号,它激发的声表面波驱动其声路径上微通道中的微流体沿微通道输运、合并,并快速混合。对2μl水-2μl蓝色染料微流体和2μl甘油-2μl蓝色染料微流体进行混合实验,结果表明,声表面波的作用可以提高微通道中微流体的混合速度,且混合程度更高。

Micro-mixer for Digital Micro-fluids on Piezo-electrical Substrate with Micro-channel

The movement of a digital micro-fluid on piezo-electrical substrate would deviate from propagation direction of surface acoustic wave,especially when its hydrophobic surface is not smooth. And this would be difficult to mix digital micro-fluids. A micro-mixer fabricated on 1280 YX-LiNbO3 substrate was developed,which integrated T type PDMS micro-channel,IDTs and reflectors. Two digital micro-fluids for mixture were piped into micro-channels in acoustic paths by a micro-injector and then were transported,merged and fast mixed using surface acoustic wave excited by RF signal. The mixture experiments of 2 μl water-2 μl blue dye and of 2 μl glycerol-2 μl blue dye showed that the mixture velocity and degree of the digital micro-fluids were improved by surface acoustic wave.