This invention introduces a diaphragm-less, viscosity-driven microphone that measures air particle velocity instead of pressure. Using microfabricated viscous-coupled elements, it achieves high directional sensitivity, broadband response, and resistance to environmental noise. Inspired by biological flow sensors, it enables compact, low-cost, and precise acoustic detection for next-generation audio and sensing applications.
Traditional microphones rely on diaphragm deflection to detect pressure fluctuations, a method that limits directional sensitivity and responsiveness to air particle motion. Such designs struggle with wind noise, low-frequency disturbances, and restricted frequency range, making them unsuitable for precise sound source localization and acoustic intensity measurements. A new approach is needed to measure air particle velocity directly and achieve directional, high-fidelity acoustic detection in a miniaturized format.
This invention introduces a diaphragm-less microphone that detects acoustic particle velocity using microfabricated thin sensing elements driven by viscous coupling with air motion. These lightweight beams, connected by compliant torsional pivots to a central platform, rock out of phase in response to air velocity changes. The motion is transduced via capacitive sensing electrodes to produce precise directional acoustic signals. The design mimics biological flow sensors, providing broadband frequency response, environmental robustness, and manufacturability using standard MEMS processes.
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• Inherent directional sensitivity through vector velocity detection
• Robust operation resistant to wind and low-frequency noise
• Broad and flat frequency response over a wide acoustic spectrum
• Miniaturized, planar design compatible with standard MEMS fabrication
• High sensitivity due to viscous force–driven air motion coupling
• Simplified, low-cost production enabled by two-mask microfabrication process
• Biologically inspired mechanism achieving natural-like acoustic precision
• High-fidelity audio capture for consumer electronics and communications
• Directional microphones for hearing aids and assistive listening devices
• Active noise cancellation and source localization systems
• Environmental and industrial acoustic monitoring
• Miniature flow and particle velocity sensors for diagnostic and control systems
• Biomedical acoustic sensing and physiological sound monitoring
• United States – 63/523,270 – Provisional – Filed 06/26/2023 – Converted
• United States – 18/754,629 – Utility – Filed 06/26/2024 – Status: Filed
Microfabrication and lab-scale prototype.
This technology is available for licensing.
Promising for MEMS device manufacturers, audio electronics firms, and sensing technology developers seeking compact, biologically inspired directional microphones with superior noise resistance and acoustic precision.
Prototype fabrication data and performance test results available upon request.