  Most materials exhibit positive Poisson's ratio (PR) values but special
structures can also present negative and, even rarer, zero (or close to zero)
PR. Null PR structures have received much attention due to their unusual
properties and potential applications in different fields, such as aeronautics
and bio-engineering. Here, we present a new and simple near-zero PR 2D
topological model based on a structural block composed of two smooth and rigid
bars connected by a soft membrane or spring. It is not based on re-entrant or
honeycomb-like configurations, which have been the basis of many null or
quasi-null PR models. Our topological model was 3D printed and the
experimentally obtained PR was$-0.003\,\pm 0.001\,$, which is one the closest
to zero value ever reported. This topological model can be easily extended to
3D systems and with compression in any direction. The advantages and
disadvantages of these models are also addressed.
