Estimating Droplet Size with Microphones
A new method utilizes condenser microphones and neural networks to estimate droplet radius from resonant frequency.
Liquid aerosols have numerous applications, and knowing their droplet size distribution is crucial for understanding the dynamics of these processes.
- Viral particles
- Perfume
- Mist
Current methods for measuring droplet size, such as laser diffraction, are expensive and complex. Avshalom Offner developed an inexpensive method to indirectly estimate the size of aerosol droplets using microphones.
An electret condenser microphone acts like a parallel plate capacitor.
Offner dripped water droplets of varying sizes onto the microphone surface using a precise pipette. Upon impact, each droplet vibrated the top plate at a distinct resonant frequency, resulting in a voltage change on the microphone.
Author's summary: Microphones estimate droplet size.