At the CES 2020 trade show in Las Vegas, Nissan debuted a new lightweight sound insulation material to help keep road noise from infiltrating the cabin.
- Nissan invented a new acoustic meta-material to control wide-frequency band noise in a vehicle’s cabin.
- Lighter than conventionally used materials, it’s just as effective, costs the same and has the added bonus of increasing efficiency.
- New methods to reduce noise will become even more important as we transition to inherently quieter electric vehicles.
The new acoustic meta-material is a simple and lightweight combination of a lattice structure and plastic film. (Photo: Nissan)
Lightweight and cost effective
Back around 2008, Nissan began doing research on meta-material. At that point in time, it was used on high-sensitivity antennas used for electromagnetic wave research. Nissan saw the potential for the application in insulating against sound waves on the road, resulting in the invention of its acoustic meta-material.
The acoustic meta-material uses a simple combination of a lattice structure and plastic film to control air vibrations to limit the transmission of wide frequency band noise (500-1200 hertz). Those earsplitting, body-rattling sounds are the result of road and engine noise. Road noise ranges from 700-1300 hertz.
To dampen this high frequency, the current “state-of-the-art” is to use heavy rubber board. Nissan’s new acoustic meta-material lops off three-quarters of the weight while getting the job done just as effectively. Due to its simple structure, Nissan claims it meta-material will cost the same or less than current materials utilized when produced at scale. Of course, shaving weight from the vehicle is important, as it boosts energy efficiency.
Sounds reaching just 500Hz cause discomfort. Make sure your volume is set to a low level before you enter the test zone. (Video: YouTube)
WHY THIS MATTERS
Although electric motors are virtually silent in comparison to gas-powered engines, road noise is still an issue. This can be exacerbated by the absence of the gas-engine roar. If Nissan can produce its meta-material at scale, it can help create that pleasant cabin experience passengers expect, while also increasing the energy efficiency of future EVs.