用于微全分析系统的数字化微流控芯片的研究

Studies on Digital Microfluidic Chip for Micro-Total-Analysis Systems

研制出一种基于介质上电润湿(electrowetting-on-d ielectric,EWOD)机制的可编程数字化微流控芯片。它采用“三明治”结构:受控离散液滴被夹在两极板之间;下极板以硅为衬底,掺杂多晶硅作为芯片微电极阵列,其上涂覆有Teflon(AF1600薄膜的S iO2作为疏水性介质层;上极板是涂覆有Teflon(AF1600疏水薄膜的透明电极。通过分析数字化微流控系统的基本操作(离散液滴的传输、拆分及混合)的物理机理和模拟优化,在35 V低驱动电压下实现了约0.35μL和0.45μL去离子水离散液滴的传输和合并,并在70 V驱动电压下实现了0.8μL液滴的拆分等操作。

A programmable digital microfluidic chip based on electrowetting-on-dielectric is presented, consisting of a sandwiched configuration. The controlled droplets were sandwiched between two parallel plates. The bottom plate consists of silicon used as the substrate, a heavy doped poly-silicon as the microelectrode array, a SiO2 film spin-coated by a Teflon AF1600 film as the hydrophobic dielectric layer. The top plate is a transparent electrode spin-coated by a Teflon AFI600 film. The physical mechanisms and simulations of the fundamental fluidic operations （transporting, cutting, and merging） based on electrowetting-on-dielectric were researehed. The operations of transporting and merging on deionized droplets of 0.35μL and 0.45μL were successfully achieved in air by applying the low actuation voltages of 35 V, and the cutting operation on the deionized droplet of 0. 8 μL was also achieved by applying the voltage of 70 V.