Created by scientists at Switzerland's ETH Zurich research institute and the University of Fribourg, the experimental composite is composed of laminated alternating layers of two materials. One of these is a previously developed synthetic version of nacre. Also known as mother-of-pearl, the natural version of nacre is composed of stacked-brick-like calcium carbonate plates, and it's what gives certain types of mollusc shells their hardness and stiffness. ETH's synthetic version is similarly tough, but is made of aligned aluminum oxide plates that are joined together via a mixture of epoxy resin and titanium oxide particles.