Nacre, the inner lining of seashells, has both high stiffness and high fracture toughness, making it an exquisite structural material.

The toughness of nacre derives from its complex nanostructure, where stacked layers of 500 nm-thick calcium carbonate platelets are separated by 20-nm-thick layers of sticky, elastic biopolymers.

Naturally occurring nacre

Bacterial nacre made in the Meyer lab

The Meyer lab can fabricate artificial nacre by using only bacterially-produced materials that are inexpensive and environmentally-friendly. We are developing techniques to tune the flexibility and the 3D-shape of our nacre to make more advanced materials.

The Meyer lab uses two strains of bacteria to produce a layered structure that mimics the structures produced by mollusks. The final material resists shattering, and mechanical analysis shows that it is as tough as naturally occurring nacre.

In addition to nacre, we are also using bacteria to create advanced materials with unique electrical and optical properties, such as graphene and microlenses.

•Spiesz EM*, Schmieden DT*, Grande AM, Liang K, Schwiedrzik J, Natalio F, Michler J, Garcia SJ, Aubin-Tam M-E, Meyer AS. Bacterially-produced, nacre-inspired composite materials. Small (2019), *equal contributions

•DT Schmieden, AS Meyer, ME Aubin-Tam. Using bacteria to make improved, nacre-inspired materials. MRS Advances (2016), 1 (8), 559-564