The nascent engineered living material (ELM) field seeks to directly harness natural and synthetic living processes to imbue materials with responsive and adaptive behaviours. Top-down fabrication, where microorganisms are incorporated into a fabricable material, has been utilised in the majority of ELM designs so far. However, to capture a principle component of natural living materials, i.e., autonomous proliferation and growth, bottom-up approaches to materials design must be explored. Indeed, natural biofilms of non-motile microorganisms have been shown to utilise cyclical osmotic swelling of secreted extracellular polymeric molecules to expand their growth front. In this project, the aim is to recapitulate this osmotic-swelling-driven expansion to enable continual construction and growth of a microbial cell laden biopolymeric network in 3D. The successful candidate will investigate both the physical swelling of the biopolymer network, and the potential for the swelling-induced transport of vegetative cells from the central core to an external growth front.

Osmotically-driven expansion of a bacterial biofilm after hyperosmotic shock (from Yan et al., Nature Communication 8, 327, 2017.)