Quiet spaces can be created using sound-absorbing silk.

Researchers at MIT and other institutions have developed a sound-absorbing silk fabric that can be used to create quiet spaces in a noisy world. The fabric, which is incredibly thin and contains a special fiber that vibrates when an electrical voltage is applied to it, can suppress sound in two different ways. One technique involves generating sound waves that interfere with unwanted noise to cancel them out, similar to the concept of noise-cancelling headphones. The other technique is to hold the fabric still to suppress vibrations that transmit sound, effectively reducing noise in larger spaces such as rooms or cars.

The research team used common materials like silk, canvas and muslin to create practical noise-canceling fabrics for real-world use. These fabrics could be used to create partitions in open work spaces or thin walls in buildings to prevent sound from passing through them. By harnessing the vibrations of the piezoelectric fiber inside the fabric, the researchers were able to develop a fabric speaker that emits sound waves to destructively interfere with unwanted noise. This innovation can significantly reduce the volume and transmission of sound in various environments, providing a new mechanism for creating quiet spaces with a thin sheet of fabric.

The study’s lead author, Grace (Noel) Yang, along with other collaborators from MIT and various universities, have made significant progress in the field of sound suppression with their sound-absorbing silk fabric. By applying electrical signals to the fabric’s piezoelectric fiber, the researchers were able to control vibrations and generate sound waves that cancel out unwanted noise. The fabric also has the ability to reflect sound when it is still, effectively reducing the transmission of noise through it.

Future research efforts will focus on exploring the use of fabric to block sounds of multiple frequencies, which may require complex signal processing and additional electronics. The team also plans to further study the architecture of the fabric and how tuning factors such as the number of piezoelectric fibers, stitching direction and applied tensions could improve its performance. By turning various “knobs” to control structural vibrations and suppress sound, researchers aim to continue refining their sound-absorbing fabric for maximum effectiveness in creating quiet spaces.

This groundbreaking work is supported by funding from organizations including the National Science Foundation, the Army Research Office, the Defense Threat Reduction Agency, and the Wisconsin Alumni Research Foundation. Interdisciplinary collaboration between researchers from different institutions and expertise in various fields was crucial to the success of this project. Moving forward, the team aims to advance its understanding of fabric technologies for noise cancellation and continue to develop innovative solutions to combat the problem of unwanted noise in our environment.