Soundproofing Silk Curtains: The New Frontier of Silence

Starting from the fascinating observation that it’s much more difficult to create silence than noise, a team led by MIT researchers, using and developing a series of studies from previous research groups, has created prototypes of soundproofing curtains capable of absorbing up to 90% of external noise.

The material chosen for the production of the noise-reducing curtain, in order to optimize the effectiveness of the research, is a natural silk fabric.

The world we live in is increasingly characterized by the presence of noise. Noise, especially unwanted noise, at high levels or at particular times of the day, poses a problem for the quality of life and coexistence.

Research into noise-reducing materials and sound-absorbing curtains is becoming increasingly important, and new materials and technologies are in demand. Unfortunately, often, primarily for cost reasons, synthetic materials derived directly from petroleum are used. These materials are thick and bulky, causing high levels of pollution during their production, use, and, above all, disposal.

Scientists have combined a pure natural silk fabric, just thicker than a human hair, with a special fiber that vibrates when applied to it, creating a piezoelectric soundproofing fabric.

The evolution developed by MIT researchers to create a noise-reducing silk fabric began with the assumption that sound waves striking the silk fabric and piezoelectric fiber stiffen the silk fabric structure. This stiffening, acting like a mirror, prevents noise propagation even in very large spaces such as rooms, cars, or recording studios. The silk soundproofing fabric is held firm and rigid by sound waves propagated from noisy sources and suppresses any vibrations necessary for sound propagation, effectively canceling the noise.

The application of silk’s excellent chemical, physical, and especially mechanical properties in the soundproofing field provides essential support for piezoelectric fibers.
Silk fiber exhibits:

• Porosity and amorphous phases: within the structural matrix of its constituent proteins, fibroin and sericin are essential for absorbing certain types of sound waves.
• Molecular construction: the overlapping layers with an internal B-sheet structure increase the ability to refract sound waves.
• Insulation: high thermal, electrical, and acoustic insulation properties.
• Fiber microstructure: the individual fibrils are compact, thin, and smooth. They create a structure that blocks the diffusion of sound waves.
• Lightness and density: the fibers are lightweight with sufficient density to dampen medium-high frequencies, such as voices, ringing, or instrument noises.

The combination of these different features has led to the development of acoustic silk curtain prototypes that:

• Directly suppress approximately 65 decibels
• Indirectly suppress approximately 70% of sound

The noise generated by a group of friends in the next apartment talking and laughing at high volume could be eliminated by a simple, elegant silk curtain with a thickness of less than 0.15 millimeters
This is possible with thicknesses and volumes that are completely unmatched by the sound-absorbing panels commonly used in acoustics or noise reduction.

Silk soundproofing curtains or more complex silk sound-absorbing panel designs can be used in various contexts:

• Private homes: between adjoining rooms, to improve sleep or create quiet zones.
• Hotels and hospitality facilities: as an elegant and functional solution to increase acoustic privacy.
• Creative workspaces: to separate noisy areas from those dedicated to concentration.