  Vibration energy harvesting is a technology that enables electric power
generation by augmenting vibrating materials or structures with piezoelectric
elements. In a recent work, we quantified the intrinsic energy-harvesting
availability of a piezoelectric phononic crystal (Piezo-PnC) by calculating its
damping ratio across the Brillouin zone and subtracting off the damping ratio
of the corresponding non-piezoelectric version of the phononic crystal. It was
highlighted that the resulting quantity is indicative of the amount of useful
energy available for harvesting and is independent of the finite structure size
and boundary conditions and of any forcing conditions. Here we investigate the
intrinsic energy harvesting availability of two other material systems chosen
to be statically equivalent to a given Piezo-PnC: a piezoelectric locally
resonant metamaterial (Piezo-LRM) and a piezoelectric inertially amplified
metamaterial (Piezo-IAM). Upon comparing with the intrinsic energy harvesting
availability of the Piezo-PnC, we observe an emergence of energy harvesting
capacity, a phenomenon we refer to as metaharvesting. This is analogous to the
concept of metadamping, except the quantity evaluated is associated with
piezoelectric energy harvesting rather than raw dissipation. Our results show
that the intrinsic energy harvesting availability is enhanced by local
resonances, and enhanced further by inertial amplification. These findings open
a pathway towards fundamental design of architectured piezoelectric materials
with superior energy harvesting capacity.
