Make engineered living materials carry their weight

Engineered living materials (ELMs) are a new class of materials synthesized and/or populated by living organisms. ELMs have the potential to reduce energy costs in manufacturing and provide desirable material functionalities including self-healing and sensing. To substantially reduce carbon emissions, ELMs must be able to replace rigid materials. However, naturally occurring materials synthesized by cells are not sufficiently stiff to replace rigid engineering materials. Furthermore, the cellular viability in the stiffest ELMs is not yet adequate for achieving their sustainability potential. The need for rigid ELMs will require new approaches to enhance cell viability and/or combine living cells with rigid scaffolds. Among naturally occurring materials, bone is a rare example of a rigid material that is synthesized and functionalized by cells that maintain impressive viability. Bone is expected to provide lessons for surmounting challenges in achieving the requisite viability and mechanical properties required for ELMs to serve common load-bearing purposes.