Lightweight high-isolation material (acoustic meta-material)
A lightweight sound isolation material that offers a quiet cabin experience
Acoustic
meta-material
offers
outstanding
cabin
quietness
through
the
use
of
lightweight
high-isolation
panels
in
a
lattice
structure
with
membranes.
System operation
A
combination
of
a
lattice
structure
and
plastic
film
membrane
controls
air
vibrations
to
limit
the
transmission
of
wide
frequency
band
noise
(500-1200Hz),
such
as
road
and
engine
noise.
Currently,
most
materials
used
to
isolate
this
frequency
band
consist
mainly
of
heavy
rubber
board.
Nissan’s
new
acoustic
meta-material
weighs
one-fourth
as
much
as
these
while
providing
the
same
degree
of
sound
isolation.
Under
1000Hz,
acoustic
meta-material
is
highly
effective
in
suppressing
road
noise
and
improving
sound
isolation,
creating
an
enjoyable,
in-cabin
experience.
Making
vehicles
lighter
helps
limit
the
environmental
impact
of
driving
by
improving
energy
efficiency.
It
also
enhances
enjoyment,
as
the
quiet
vehicle
cabin
makes
driving
more
comfortable.
System mechanism
Acoustic
meta-material
manipulates
the
direction
of
acoustic
noise,
disrupting
them
in
a
way
that
results
in
sound
(noise)
suppression.
Acoustic
noise
is
classified
as
air
vibration.
When
acoustic
noise
contacts
the
meta-material,
the
meta-material
reflects
or
bounces
the
noise
back
according
to
vibrations
in
the
air.
This
effectively
reduces
the
noise
passing
or
absorbing
through
the
material
and
into
the
cabin,
according
to
physical
law
(mass
law).