A micro hemispherical glass shell resonator for online liquid density sensing of microfluidics

Rapid on-line detection of liquid density is crucial in petroleum, pharmaceutical, food processing industry and chemical industries. In this article, we present a novel resonating liquid densitometer with a micro hemispherical glass shell suitable for integration with microfluidic systems. The fluid density is measured via the change in resonant frequency caused by an added mass of fluids. The densitometer was characterized with different liquid solutions. Experimental results are in reasonable agreement with the theory and show good linear behavior of the densitometer. Results by a finite element model of the hemispherical glass shell correspond well with the measured resonant frequency values. The densitometer would be potentially suitable for on-line detection of multiple liquid samples due to its simple structure, high performance, cost effectiveness and easy processing.