Professor Naoki Hosoya of the Department of Mechanical and Functional Engineering, Faculty of Engineering, Shibaura Institute of Technology has developed a speaker that vibrates "artificial muscles" at high speed to produce sound.
Dielectric Elastomer Actuator (hereinafter referred to as "DEA"), which is expected to be applied to artificial muscles, power generation devices (energy harvesting), soft robots, etc., has been attracting attention in recent years.The speaker developed this time makes this DEA into a self-supporting hemisphere or a balloon-like sphere and vibrates to produce sound. DEA has a capacitor structure in which a polymer dielectric film is sandwiched between flexible electrodes, and has a mechanism in which the electrodes are deformed by attracting each other due to electrostatic force due to a potential difference between the electrodes.
This speaker, which was developed by taking advantage of the characteristics of DEA, which is lightweight and flexible but can generate a large displacement, has almost omnidirectional acoustic radiation characteristics in the range that can be heard by humans, and is centered on the speaker. It is possible to deliver sound to the direction.In addition, since the material itself vibrates and generates sound, it has the advantage of not limiting the shape of the speaker.It weighs only a few grams and can be installed in different locations and conditions.
The speakers developed this time open up new possibilities for stage layouts in concerts and the like.In addition, it can be expected to be used as a point sound source required for acoustic tests, for example.In order to understand the characteristics of room acoustics in concert halls, it is ideal to measure the reverberation time by an acoustic test using a point sound source, but if the speaker is relatively large with respect to the sound field, it should be regarded as a point sound source. I can't.On the other hand, the speaker developed this time seems to be able to realize a point sound source regardless of the sound field and size.
The research team plans to accelerate research toward the development of speakers that can provide sounds that are easy for various people to hear.
