A concept of a planar modular mechanical metamaterial inspired by the
nature's principle of local adaptivity is proposed. The metamaterial consists
of identical pieces similar to jigsaw puzzle tiles. Their rotation within
assembly provides a substantial flexibility in terms of structural behavior and
mechanical interlocks enable reassembly. The tile design with a diagonal
elliptical opening allows us to vary elastic properties--from stiff to
compliant, with positive, zero, or negative Poisson's ratio. The outcomes of
experimental testing on additively manufactured specimens confirm that the
assembly properties can be accurately designed using optimization approaches
with finite element analysis at heart.Comment: 9 pages, 8 figure