Biodegradable, Bifunctional Electro-acoustic Transducers Based on Cellular Polylactic Acid Ferroelectrets for...

Area of Science:

• Materials Science
• Acoustic Engineering
• Sustainable Electronics

Background:

• Growing reliance on smart electronics contributes to electronic waste.
• Need for sustainable electronic materials with improved performance and biodegradability.
• Existing electroacoustic devices often lack environmental consideration.

Purpose of the Study:

• To fabricate a biodegradable and flexible bifunctional electroacoustic transducer.
• To evaluate its performance as both a microphone and a loudspeaker in air.
• To demonstrate its potential for eco-friendly applications in IoT and AI.

Main Methods:

• Fabrication of a flexible electroacoustic transducer using cellular polylactic acid (PLA) ferroelectret films.
• Characterization of acoustic impedance, figure of merit (FOM), and signal-to-noise ratio (SNR).
• Testing of microphone sensitivity and loudspeaker sound pressure levels (SPLs) across various frequencies.

Main Results:

• The device exhibits low acoustic impedance (∼0.02 MRayl) and high FOM (∼11 GPa^-1).
• Achieved a prominent SNR of ∼23.5 dB @1 kHz.
• Demonstrated high microphone sensitivity (4.2 mV/Pa) and loudspeaker SPLs (60-103 dB) over a broad frequency range (1-80 kHz).

Conclusions:

• The PLA ferroelectret-based transducer offers high-performance acoustic-electric conversion.
• Its flexibility, biodegradability, and bifunctionality make it suitable for advanced, eco-friendly electronic applications.
• The device enables accurate speech recognition and control, supporting the development of sustainable IoT and AI technologies.