In a recent press release, Asahi Glass (AGC) announced the development of a ‘sound emitting’ glass. They will demonstrate this new material at Milan Design Week 2018.
The new material is capable of creating clear and steady sounds over the whole frequency range. They will be demonstrating this sound glass in an installation called soundscape, which is a transparent glass container suspended in air and emitting sound waves. In simpler words, they created a glass loudspeaker.
While transparent speakers already exist, they are typically made from polymers, which are sensitive to attracting dust and are easy to scratch. In most of these cases the sound creating membranes are made from the typical materials with high sound dampening properties. Glass by itself has many resonances throughout the frequency bands that makes it a poor material for designing loudspeakers.
AGC sound emitting glass in comparison to an ideal material and other materials, Source: AGC
The graphs shows that the ideal material for making a loudspeaker has the same acoustic pressure level at every frequency. While monolithic glass has many resonance points throughout the frequency spectrum, the new developed material has only one resonance point at very low frequency. This is achieved by adding an interlayer that eliminates almost all of the resonances. AGC does not disclose what they are using as the interlayer other than saying that the material is transparent.
So far AGC has mentioned applications in windows, walls, ceilings, floors, lighting, furniture, mirrors and a wide range of other applications as good targets for this material. While they do not mention electronic applications at this point, such a solution would make for interesting CE devices like TVs, monitors, notebooks, tablets, smartphones, etc. A completely sealed device that emits good audio would certainly be of interest.
Analyst Comment
In the automotive industry acoustic glass has been available for quite some time, achieving a 2-3 db reduction in outside noise. This is achieved by using an improved acoustic dampening PVB material that is laminated into the windshield. AGC offers such a solution as a laminated acoustic glass. It does not seem unreasonable to assume that this new material is the further development of this technology. (NH)
