Patent attributes
A propeller includes a rotatable hub and at least two propeller blades coupled to the rotatable hub. Each of the propeller blades is formed from a combination of a first material having a negative Poisson's ratio (NPR) and a second material having a positive Poisson's ratio (PPR). The first material and the second material can be layered or can be formed as a matrix with one of the first or second material embedded in the other. In a layered configuration, a layer of the first material is positioned between adjacent layers of the second material, and the layers can be connected by tabs of NPR material. The combination of the NPR and PPR materials improve the strength and impact resilience of the propeller blades compared to conventional materials.