Although 3D printing has been a game-changer in many industries for creating new synthetic materials, scientists are also turning to nature in order to develop some of the strongest synthetic materials available. One natural substance scientists have studied as a model for creating synthetic materials is nacre, also known as mother-of-pearl. Being an exceptionally tough, stiff material produced by some mollusks and serving as their inner shell layer, it also comprises the outer layer of pearls, giving them their lustrous shine. But while nacre’s unique properties make it an ideal inspiration in the creation of synthetic materials, most methods used to produce artificial nacre are complex and energy intensive. The good news is researchers may have found a solution to this problem. A biologist at the University of Rochester has invented an inexpensive and environmentally friendly method for making artificial nacre using an innovative component: bacteria. The artificial nacre is made of biologically produced materials and has the toughness of natural nacre, while also being stiff, and surprisingly bendable. Although nacre-inspired materials have been created synthetically before, the methods used to make them typically involve expensive equipment, extreme temperatures, high-pressure conditions, and toxic chemicals. With the new method, however, all researchers have to do is grow a specific type of bacteria, put it in a solution containing another type of bacteria, and let it sit in a warm place. One of the most beneficial characteristics of the end product is that it is biocompatible—made of materials the human body produces or that humans can eat naturally anyway. This makes the nacre ideal for medical applications like artificial bones and implants.