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Academy Groundbreaking Research Next-Gen Materials

Assoc. Prof. Gal Shmuel and his research group
are developing novel materials that enable the
researchers to control waves passing through
them by electrically adjusting momentum –
a discovery with many potential applications:
from channeling energy to acoustic camouflage

The project Assoc. Prof. Gal Shmuel’s research group The DiscoveryAssoc. Prof.
uses analytical and numeric tools to study Gal Shmuel
the dynamic behavior of elastic materials.
This research helps the group develop The group has developed a model for
metamaterials – engineered materials metamaterials with a new property that does
with properties not found in nature. In not exist in naturally-occurring materials. These
the context of dynamics, the vision for materials gain momentum in response to an
metamaterials is the ability to control how they electric field. The balance of momentum in an
conduct waves. This ability is very important object determines how energy flows through it
for numerous engineering applications: from in the form of elastic waves. Because of this, the
improved sensors to energy channeling and newly discovered property allows researchers to
acoustic camouflage. control the flow of energy and the generated waves
by controlling momentum electrically. This property,
Willis coupling
Elasticity called electromomentum, is important to solving many
stress & strain
problems, like acoustic camouflaging: when the waves
around an object are identical to the waves that would
Piezoceoleucptlrinicg

have been there in its absence, the object becomes
hidden. The group’s model brings us closer to mimicking
Dynamics Electro- Electrostatics this ability by controlling the waves an object generates.
momentum & momentum
electric displacement
Working toward this discovery, the researchers used
homogenization theory: a theory that links observable
velocity
coupling & electric Þeld
physical phenomena to structures of matter on a smaller
scale. By developing this theory, the group has shown
An illustration showiEnlagsttihcietycouplings that geometrically asymmetrical materials composed
between different pstrheysssi&csatlrafiine
lds. of piezoelectric elements (elements that deform
when an electric field is applied to them) develop an
Discovered by the group, electromomentum effective momentum in an effective electric field. Using
calculatory examples, the group then showed how this
coupling refers taoncdoeulpelcintrgosbteattPwiciezefoicemeoanuglpdnlienstgic
.
property can be used to control waves reflected by the
electrodynamic metamaterial.
Willis coupling
The group’s first peer-reviewed article on this topic
was published last year in the Journal of Mechanics
and Physics of Solids, the leading journal in the field
of mechanics. More recently, the group published
its calculatory examples in Wave Motion, a journal
dedicated to the study of wave phenomena.

26 | MEgazine | Faculty of Mechanical Engineering

Dynamics Magnetostatics