A novel technique for measuring pico-scale flow rate of a liquid solution using a microchannel

As micrototal analysis system (μ-TAS) becoming more extensively used, techniques for fabricating microchannels, microactuators, and measuring systems are becoming increasingly important. This study describes a novel method for fabricating a closed microchannel that can be used to measure the pico-scale flow rate of a liquid solution with an accuracy of better than 1 pL/s. The flow rate of 9 pL/s is calculated from the measurements. Without any high temperature or high-voltage processing, the microchannel can be integrated in the complementary metal-oxide-semiconductor (CMOS) microfluidic system and the fabricating process involves only some standard CMOS processes and common materials. The batch fabrication of a single integrated circuit (IC) chip is essential to reaching the goal of a system in one chip.