Passive wireless MEMS microphones for biomedical applications

Area of Science:

• * Biomedical Engineering
• * Materials Science
• * Electrical Engineering

Background:

• * Traditional acoustic sensors often require batteries and wired connections, limiting their application in certain biomedical scenarios.
• * Existing wireless telemetry systems can be bulky or expensive, hindering the development of disposable or miniature sensor solutions.
• * There is a need for low-cost, miniaturized, and battery-less acoustic sensors for continuous and non-invasive patient monitoring.

Purpose of the Study:

• * To develop and evaluate passive wireless Surface Acoustic Wave-Interdigital Transducer (SAW-IDT) MEMS microphones for high-frequency acoustic sensing.
• * To demonstrate a novel sensing strategy for pulse-modulated SAW-IDT sensors that does not require calibration.
• * To explore the potential of these sensors for disposable and wireless biomedical monitoring applications.

Main Methods:

• * Fabrication of wireless, battery-less SAW-IDT MEMS microphones using batch manufacturing techniques.
• * Implementation of a pulse-modulated sensing strategy detecting the AC component of acoustic pressure signals.
• * Testing and evaluation of sensor performance, including wireless telemetry distance and integration with a MEMS microphone.

Main Results:

• * Successful implementation of the pulse-modulated SAW-IDT sensing strategy on fabricated sensors.
• * Achieved wireless telemetry distances of up to 5 centimeters.
• * Demonstrated the feasibility of a complete passive wireless sensor package including a MEMS microphone and SAW-IDT device.

Conclusions:

• * The developed passive wireless SAW-IDT MEMS microphones offer a promising solution for low-cost, disposable acoustic sensing.
• * This technology enables new possibilities for wireless monitoring of body sounds in diverse biomedical applications, including neonatal care and post-operative monitoring.
• * The battery-less and miniature nature of these sensors minimizes patient discomfort and expands the scope of wearable health monitoring devices.