Soundproofing has been around for decades, with various approaches attempting to reduce the impact of sound pressure created by machinery and other ambient sources. The need for soundproofing ranges from protecting the health of people impacted by sound at destructive levels and frequencies to eliminating unwanted acoustic impact during scientific or technical work. It also becomes important when there’s a need to reduce aggravation and related negative perceptions of people who are exposed to sound pollution generated by business activity.
Methods for mitigating the negative impacts of sound include noise barriers or sound dampening structures, which can be heavy and expensive, sound generators such as noise cancellation headphones that have limited effectiveness, or increasing the distance between the source of the sound and the recipient, which can impact the critical placement of machinery and other sources of sound. But Jabil is always searching for new technology applications to address business problems, even if the applications are not currently requested from our customers. One of Jabil’s research and development efforts in this area is starting to show promising value.
Jabil researchers launched a project to study the different properties of metamaterials and how they might impact the performance of acoustic technology. They started experimenting with a technology known as an acoustic hyperlens as a guide. This is a ground-breaking technology that is attempting to increase the performance of devices that use sound to map a 3-dimensional space (think medical scanners, underwater sonar, etc.). But what they discovered was an entirely new application that transformed and controlled sound, instead of using it simply for image mapping.
The Jabil team determined that metamaterial’s geometric forms could actually change the direction of the soundwaves themselves, which is now taking the team in the direction of use cases such as industrial sound deadening or unique soundproofing applications in spaces where noise pollution requires control.
Metamaterials are man-made materials that have engineered properties that do not occur in nature. The materials used by the Jabil team have inherent anisotropic properties, which means that the properties vary in different directions through the material. The Jabil team was able to use these properties to transform the directional behavior of sound waves.
By utilizing additive manufacturing, the Jabil team was able to create very complex geometries within 3D printed components that are not possible through traditional manufacturing techniques such as CNC production. Through specialized 3D printing techniques, the team was able to orient the metamaterial structure to allow the transformation and redirection of traveling soundwaves passing through the structure.
By reversing the direction of a soundwave and reflecting it back to its source or pointing it in a direction that can be dictated by the designer, new types of sound shielding can be developed for industrial machinery. Since the additive-manufactured metamaterial structure will be redirecting sound and not trying to absorb it, the material can be much lighter and more cost-effective to produce than traditional sound insulation material.
This approach can be used to soundproof any space that requires noise pollution reduction and in other applications where sound needs to be isolated and controlled. It could be produced as a standalone shield or used in tandem with existing soundproofing technologies.
Jabil is at the beginning of what could be the evolution of entirely new industries involving the transformation of sound, and it’s all been made possible through metamaterials and additive manufacturing.