Science Advances,
Journal Year:
2021,
Volume and Issue:
7(45)
Published: Nov. 3, 2021
In
linear,
lossless,
time-invariant,
and
nonbiased
acoustic
systems,
mode
transitions
are
time
reversible,
consistent
with
Lorentz
reciprocity
implying
a
strict
symmetry
in
space-time
for
sound
manipulation.
Here,
we
overcome
this
fundamental
limitation
by
implementing
spatiotemporally
modulated
metamaterials
that
support
nonreciprocal
steering.
Our
mechanism
relies
on
the
coupling
between
an
ultrathin
membrane
external
biasing
electromagnetic
fields,
realizing
programmable
dynamic
control
of
impedance
over
motionless
noiseless
platform.
The
fast
flexible
modulation
our
metamaterial
imparts
effective
unidirectional
momentum
to
realize
k-ω
space
different
diffraction
modes.
On
basis
these
principles,
demonstrate
efficient
steering,
showcasing
evanescent
wave
conversion
upconversion
focusing.
More
generally,
platform
offers
opportunities
generation
Bloch
waves
extension
other
domains,
such
as
non-Hermitian
topological
parity-time
symmetric
acoustics.
Reviews of Modern Physics,
Journal Year:
2022,
Volume and Issue:
94(2)
Published: April 22, 2022
As
devices
and
circuits
scale
to
ever
smaller
sizes
thermal
management
in
them
becomes
more
important,
heat
transport
across
their
interfaces
plays
a
crucial
role
development.
While
the
study
of
interfacial
resistance
goes
back
almost
90
years,
its
increasing
importance
has
led
significant
recent
progress
theory,
experiment,
simulation.
This
review
chronicles
this
for
solid-solid,
solid-liquid,
solid-gas
interfaces,
discusses
how
tailor
minimize
resistance,
mentions
some
remaining
challenges.
Annual Review of Condensed Matter Physics,
Journal Year:
2023,
Volume and Issue:
14(1), P. 471 - 510
Published: March 10, 2023
Elasticity
typically
refers
to
a
material's
ability
store
energy,
while
viscosity
tendency
dissipate
it.
In
this
review,
we
discuss
fluids
and
solids
for
which
is
not
the
case.
These
materials
display
additional
linear
response
coefficients
known
as
odd
elasticity.
We
first
introduce
elasticity
from
continuum
perspective,
with
an
emphasis
on
their
rich
phenomenology,
including
transverse
responses,
modified
dislocation
dynamics,
topological
waves.
then
provide
overview
of
systems
that
range
quantum
fluids,
astrophysical
gasses,
active
driven
matter.
Finally,
comment
microscopic
mechanisms
by
arise.
Reports on Progress in Physics,
Journal Year:
2021,
Volume and Issue:
84(8), P. 086502 - 086502
Published: Jan. 14, 2021
The
introduction
of
engineered
resonance
phenomena
on
surfaces
has
opened
a
new
frontier
in
surface
science
and
technology.
Pillared
phononic
crystals,
metamaterials,
metasurfaces
are
an
emerging
class
artificial
structured
media,
featuring
that
consist
pillars—or
branching
substructures—standing
plate
or
substrate.
A
pillared
crystal
exhibits
Bragg
band
gaps,
while
metamaterial
may
feature
both
gaps
local
hybridization
gaps.
These
two
band-gap
phenomena,
along
with
other
unique
wave
dispersion
characteristics,
have
been
exploited
for
variety
applications
spanning
range
length
scales
covering
multiple
disciplines
applied
physics
engineering,
particularly
elastodynamics
acoustics.
intrinsic
placement
pillars
semi-infinite
surface—yielding
metasurface—has
similarly
provided
avenues
the
control
manipulation
propagation.
Classical
waves
admitted
including
Lamb
plates
Rayleigh
Love
substrates,
ranging
frequency
from
hertz
to
several
gigahertz.
With
presence
pillars,
these
couple
resonances
richly
creating
properties
subwavelength
regime
some
at
higher
frequencies
as
well.
At
nanoscale,
it
was
shown
atomic-scale
resonances—stemming
nanopillars—alter
fundamental
nature
conductive
thermal
transport
by
reducing
group
velocities
generating
mode
localizations
across
entire
spectrum
constituent
material
well
into
terahertz
regime.
In
this
article,
we
first
overview
history
development
materials,
then
provide
detailed
synopsis
selection
key
research
topics
involve
utilization
similar
substructures
different
contexts.
Finally,
conclude
providing
short
summary
perspectives
state
field
its
promise
further
future
development.
Nature Communications,
Journal Year:
2021,
Volume and Issue:
12(1)
Published: Oct. 12, 2021
Materials
made
from
active,
living,
or
robotic
components
can
display
emergent
properties
arising
local
sensing
and
computation.
Here,
we
realize
a
freestanding
active
metabeam
with
piezoelectric
elements
electronic
feed-forward
control
that
gives
rise
to
an
odd
micropolar
elasticity
absent
in
energy-conserving
media.
The
non-reciprocal
modulus
enables
bending
shearing
cycles
convert
electrical
energy
into
mechanical
work,
vice
versa.
sign
of
this
elastic
is
linked
non-Hermitian
topological
index
determines
the
localization
vibrational
modes
sample
boundaries.
At
finite
frequency,
also
tune
phase
angle
produce
direction-dependent
properties.
Our
continuum
approach,
built
on
symmetries
conservation
laws,
could
be
exploited
design
others
systems
such
as
synthetic
biofilaments
membranes
loops.
National Science Review,
Journal Year:
2022,
Volume and Issue:
9(12)
Published: Feb. 21, 2022
Metasurfaces,
the
ultrathin
media
with
extraordinary
wavefront
modulation
ability,
have
shown
versatile
potential
in
manipulating
waves.
However,
existing
acoustic
metasurfaces
are
limited
by
their
narrow-band
frequency-dependent
capability,
which
severely
hinders
real-world
applications
that
usually
require
customized
dispersion.
To
address
this
bottlenecking
challenge,
we
report
ultra-broadband
achromatic
capable
of
delivering
arbitrary
and
frequency-independent
wave
properties
bottom-up
topology
optimization.
We
successively
demonstrate
three
functionalities,
including
beam
steering,
focusing
levitation,
featuring
record-breaking
relative
bandwidths
93.3%,
120%
118.9%,
respectively.
All
metasurface
elements
show
novel
asymmetric
geometries
containing
multiple
scatters,
curved
air
channels
local
cavities.
Moreover,
reveal
inversely
designed
can
support
integrated
internal
resonances,
bi-anisotropy
scattering,
collectively
form
mechanism
underpinning
Our
study
opens
new
horizons
for
high-efficiency
functional
devices
on
demand,
promising
extension
to
optical
elastic
metamaterials.
