Noninvasive fluid bubble detection based on capacitive micromachined ultrasonic transducers
Jiawei Yuan1,2, Zhikang Li1,2,3, Qi Ma1,2
1State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi'an Jiaotong University, 710049 Xi'an, China.
Microsystems & Nanoengineering
|February 27, 2023
Summary
Capacitive micromachined ultrasonic transducers (CMUTs) offer a novel solution for fluid bubble detection, outperforming traditional methods in size and integration. This technology enables robust, real-time monitoring in critical applications like medical devices and aerospace systems.
Area of Science:
- Materials Science
- Acoustics
- Microelectromechanical Systems (MEMS)
Background:
- Ultrasonic bubble detection is crucial for safety in industrial, aerospace, and medical fields.
- Conventional PZT transducers are limited by size, power, and integration, hindering real-time monitoring in confined spaces like ECMO and dialysis machines.
Purpose of the Study:
- To investigate the feasibility of Capacitive Micromachined Ultrasonic Transducers (CMUTs) for fluid bubble detection.
- To establish and validate the theoretical framework for CMUT-based bubble detection using acoustic energy attenuation.
Main Methods:
- Developed and validated theoretical models using finite element simulations.
- Fabricated CMUT chips operating at a 1.1 MHz resonant frequency.
- Experimentally measured fluid bubbles in an 8 mm diameter pipe.
Main Results:
- Successfully detected fluid bubbles with radii ranging from 0.5-2.5 mm.
- Observed a significant increase in received voltage variation with increasing bubble radii.
- Demonstrated negligible impact of bubble position, flow velocity, fluid type, and pipe characteristics on detection accuracy.
Conclusions:
- CMUTs show significant promise for non-invasive, real-time ultrasonic bubble detection.
- The CMUT-based technique is robust and feasible for various applications, including those with space constraints.
- This technology overcomes limitations of conventional transducers, enabling advanced monitoring solutions.
