Metamaterial Knows No Bounds

Dean Sigler Electric Aircraft Materials, Sustainable Aviation Leave a Comment

Jonathan Berger has come up with a foam structure that will make it more than the ephemeral filling in composite construction sandwiches.  Isomax™ foam could be the entire structure because of its unique geometry.  He claims it to be the world’s first material to achieve structural performance predicted by theoretical bounds. His letter in the journal Nature describes the geometry Berger and his collaborators created to enable such lightness, strength, and versatility.  Berger, a postdoctoral researcher at UCSB’s mechanical engineering department, worked with mechanical engineering professor Robert McMeeking and materials scientist Haydn N. G. Wadley from the University of Virginia to prove the ideas Berger first conceived in 2015. This solid foam, “a combination of stiff substance and air pockets,” uses three-dimensional pyramid and cross cell geometry to achieve high stiffness.  The ordered cells are set apart by walls forming three sides and a base, and as octahedra, reinforced inside a “cross” of intersecting diagonal walls.   This “mostly air” structure …