Cascaded bowknot-type taper based Mach-Zehnder interferometer for microfluidic flow rate sensing

摘要

In microfluidic chip applications, the flow rate plays an important role. Here we proposed a simple liquid flow rate sensor by using two cascaded bowknot-type tapers (BTTs) to form a Mach-Zehnder interferometer (MZI) as the sensing element. As the water flows in the vicinity of the BTT, the cascaded BTTs based MZI's interference spectrum changes due to its contact with water. By comparing the time-swept spectra of the cascaded BTTs MZI from the state of one BTT in water to that of another BTT in water as the water flowing over it, the flow rate can be detected. The proposed sensor has a detectable range from 0.66 mm/s to 10.6 mm/s.