Nissan's Sound Absorbing ‘Acoustic Meta-Material' Named One of the 100 Greatest Inventions of 2020 by Popular Science

author: Eric Walz   

Nissan’s lightweight acoustic meta-material uses a lattice structure and plastic film designed to control air vibrations.

As the world's automakers ramp up production of near silent battery-powered cars, new technology is being developed to help eliminate road noise from entering the cabin, which is often amplified in vehicles with electrified or fully-electric powertrains. 

Without the sounds of an internal combustion engine to help drown out unwanted noise, drivers of fully-electric cars are often more aware of wind and tire noise, especially when traveling on the highway. 

To address these concerns, Japan's Nissan Motor Co has invented a new acoustic meta-material that can help keep vehicle interiors quieter. The automaker's noise-reducing technology was recognized earlier this month by Popular Science as one of the 100 greatest inventions of 2020 in the "Best of What's New Award" in the automotive category.

Each year, the Popular Science Best of What's New Awards recognize breakthrough products and technologies that represent notworthly advancements in their categories.

Nissan debuted its Acoustic Meta-Material on the Ariya concept SUV unveiled earlier this year at CES.

Nissan's acoustic meta-material is a lightweight sound insulation material. It's designed using a lattice structure and plastic film designed to control air vibrations in order to limit the transmission of wide frequency band noise in the 500-1200 hertz frequency range. This frequency range includes typical road and engine noise from a moving vehicle. 

Automotive engineers refer to the unwanted noise as "noise vibration and harshness" (NVH) and the world's automakers have been working to reduce its for decades, especially in luxury models where a quiet, comfortable cabin is often associated with overall vehicle quality.

NVH consists of a combination of sounds and vibrations from a vehicle's drivetrain as well as road noise and ambient noise outside the vehicle, and reducing it is a challenge.

While most materials used to isolate this frequency band consist mainly of rubberized or fiber boards placed under the interior carpets and behind body panels that add weight to the vehicle, Nissan's lightweight acoustic meta-material is only one quarter of the weight of traditional sound-deadening materials, yet it provides the same degree of sound isolation to the cabin, the company claims.

Nissan is not the only automaker working to reduce unwanted cabin noise.

Electric automaker Tesla has been addressing noise issues and the use of sound dampening materials, including for the Model 3, the company's first mass-market electric car. After launching the sedan in July 2017, the Model 3 was criticized for excessive wind and road noise, but Tesla made significant improvements since the sedan was first produced.

The desire to further eliminate outside noises from the Model 3's cabin has even led to third party companies selling sound reducing kits for the electric sedan. Some kits include sheets of materials that directly fit into the wheel well or trunk of the Model 3. Sound reducing tips are frequently discussed on Tesla's owner forums online.

Nissan says the material represents a breakthrough in engineering and offers customers a relaxing, quiet cabin, while the lighter materials contribute to improving range or fuel economy.

"We plan to use acoustic meta-material in a wide range of applications – not only in luxury cars and electric vehicles, but also in vehicles where the use of heavy sound insulation materials has been limited," said Susumu Miura, Nissan's advanced material engineer in charge of the acoustic meta-material project. "Through development and use of this material, we aim to make our customers' driving experience more comfortable and enjoyable."

Nissan's acoustic meta-material is currently under development for commercialization and is one of the ways the automaker is employing advanced technology to enhance the driving experience.

Eric Walz

Originally hailing from New Jersey, Eric is a automotive & technology reporter covering the high-tech industry here in Silicon Valley. He has over 15 years of automotive experience and a bachelors degree in computer science. These skills, combined with technical writing and news reporting, allows him to fully understand and identify new and innovative technologies in the auto industry and beyond. He has worked at Uber on self-driving cars and as a technical writer, helping people to understand and work with technology.