This PFAS-free waterproof sound-permeable membrane is designed to transmit acoustic signals with minimal attenuation while providing a robust barrier against water and particulate ingress. It replaces conventional PTFE-based acoustic vents in microphones, speakers, and ultrasonic sensors. The membrane is manufactured from non-fluorinated polymers and can be supplied in custom sheet sizes, roll widths, or as die-cut parts with adhesive. It maintains excellent acoustical transparency across critical voice and ultrasonic frequency ranges, enabling clear, reliable sensor performance in wet and dusty environments.

Portable electronics, automotive parking sensors, and industrial acoustic transducers require open ports to sound, exposing internal components to moisture and dirt. Current solutions often use ePTFE acoustic mesh, which contains PFAS. New regulations and eco-conscious consumers demand PFAS-free materials. However, removing the membrane is not an option, as it would lead to rapid sensor failure from water damage. A high-performance, PFAS-free acoustic vent is essential.

Our PFAS-free sound-permeable membrane features a precise pore structure that allows sound waves to pass with minimal insertion loss, typically under 3 dB across 100–10,000 Hz. The hydrophobic surface withstands water pressure up to 50 kPa, meeting IP67 requirements. The film is available in custom thicknesses (0.05–0.20 mm) and can be combined with dedicated adhesive rings for easy assembly into sensor housings. It is fully compliant with PFAS-free directives and provides uncompromised audio quality.

• Material: PFAS-free polymer

• Thickness: 0.05–0.20 mm

• Sound insertion loss: < 3 dB at 1 kHz

• Waterproof rating: IP67, IP68 upon request

• Pore size: 0.5–2.0 µm

• Air permeability: 50–150 ml/min/cm²

• Temperature range: -40°C to 105°C

Ideal for smartphone microphones, smartwatch speaker ports, TWS earbud vents, automotive ultrasonic parking sensors, outdoor intercom microphones, and industrial acoustic emission sensors. The membrane can be custom die-cut into circles, rectangles, or complex shapes with locating tabs.

Sound waves strike the membrane and cause it to vibrate sympathetically, transmitting acoustic energy through the microporous structure. Because the pores are much smaller than the wavelength of sound, the membrane acts as an acoustically transparent window. Meanwhile, water droplets are unable to penetrate due to high surface tension, protecting the sensor element. The PFAS-free polymer does not interfere with sound propagation and retains flexibility at low temperatures.

Determine the required sound frequency range for your sensor. Submit a housing CAD model so we can recommend the optimal membrane thickness and adhesive layout to minimize resonance. Choose between standard or high-adhesion adhesives depending on your housing material (stainless steel, PC, or ceramic). We can provide acoustic test data for specific frequencies. Samples are available with pre-applied adhesive rings for immediate evaluation.