Functional protein materials: beyond elastomeric and structural proteins

In the past two decades researchers have shown great interest in mimicking biological structures and their complex structure–property relationships that have evolved from a small number of chemically similar building blocks. The great strides in this field are evident in bio-inspired materials and structures that are making their way into commercial products. Among natural biopolymers, proteins provide a versatile building block with inherent structural and functional complexity that is unmatched by synthetic materials. Herein, we review recent strategies to influence the self-assembly of protein materials whose hierarchical structure may prove useful in a variety of applications, for example in soft-robotics and energy storage.