kinetiX, 2018

a designed doubly curved helmet designed using our structure.

Metamaterial are of increasing interest to the scientists and designers. We report a group of new configurations of mechanical metamaterial that exhibits auxeticity.

An auxetic material is a material that exhibits a Negative Poisson’s Ratio (NPR). Unlike conventional materials, when an auxetic material is stretched (or compressed) in one direction, instead of becoming thinner (or thicker), it becomes thicker (or thinner) in perpendicular directions.

This project describes a group of auxetic-inspired material structures that can transform into various shapes upon compression. While the majority of the studies of auxetic materials focus on their mechanical properties and topological variations, our work proposes a parametric design approach that gives auxetic structures the ability to deform beyond shrinking or expanding for the first time. To do so, we see the auxetic structure as a parametric four-bar linkage. We developed four cellular-based material structure units composed of rigid plates and elastic/rotary hinges. Different compositions of these units lead to a variety of tunable shape-changing possibilities, such as uniform scaling, shearing, bending and rotating. By tessellating those transformations together, we can create various higher level transformations for design.

We hope this work will inspire researches in metamaterials design(micro), shape-change materials(meso) and transformabale furniture(macro). Application includes packaging design, conformable exoskeleton, or reconfigurable furniture.