A PMUT Integrated Microfluidic System for Fluid Density Sensing

TL;DR

This paper presents a novel integrated PMUT-microfluidic system capable of real-time, low-volume fluid density sensing, with potential applications in healthcare for monitoring blood density and hemoglobin levels.

Contribution

The study introduces a dual electrode PMUT integrated with microfluidics as a self-contained, high-sensitivity fluid density sensor suitable for real-time monitoring in various applications.

Findings

Successfully measured fluid densities in the range of 1020-1090 kg/m3.

Achieved a sensitivity of 26.3 Hz/(kg/m3), capable of detecting 1% changes in blood hemoglobin content.

Demonstrated potential for real-time blood density and hemoglobin monitoring.

Abstract

We demonstrate the design, fabrication and use of a dual electrode PMUT (Piezoelectric Micromachined Ultrasound Transducer) integrated with a microfluidic channel as a fluid density sensor in both static and dynamic density-change conditions. The dual electrode configuration makes the PMUT resonator a self-contained resonant peak-shift sensor and the microfluidic integration makes this system a versatile fluid density sensing platform that can be used with extremely low volumes of fluids in various industrial and healthcare applications. The density measurements carried out here under flowing fluid conditions demonstrate the potential of this system as a real-time fluid density monitoring system. We include results of density measurements in the range of 1020 - 1090 kg/m3 that corresponds to the human blood density variation generally due to the change in its hemoglobin content. The sensitivity of the sensor-26.3 Hz/(kg/m3)-is good enough to reliably detect even 1% change in the hemoglobin content of the human blood. Thus, this system could potentially be used also as a hemoglobin measurement sensor in healthcare applications.