Credit: Image courtesy of Zhibin Guan, University of California, Irvine
Scientists created a bioinspired gradient in mechanical properties. The range is achieved by programming the density of a special interaction between metal ions and electron-donating ligands. The left image is a polychaete worm jaw that uses metal-ligand interactions to create a mechanical gradient, which can prevent damage to the jaw tip during biting and venom injection. The bioinspired polymer-metal material developed in the laboratory (right) contains zinc (Zn), copper (Cu), or cobalt (Co) (all are blue) and a network of nitrogen-based ligands (green).