  This work proposes the complete design cycle for several auxetic materials
where the cycle consists of three steps (i) the design of the
micro-architecture, (ii) the manufacturing of the material and (iii) the
testing of the material. We use topology optimization via a level-set method
and asymptotic homogenization to obtain periodic micro-architectured materials
with a prescribed effective elasticity tensor and Poisson's ratio. The space of
admissible micro-architectural shapes that carries orthotropic material
symmetry allows to attain shapes with an effective Poisson's ratio below -1.
Moreover, the specimens were manufactured using a commercial stereolithography
Ember printer and are mechanically tested. The observed displacement and strain
fields during tensile testing obtained by digital image correlation match the
predictions from the finite element simulations and demonstrate the efficiency
of the design cycle.
