Title: Cellular proliferation-driven curvature changes in stimuli-responsive engineered living materials

Abstract: Stimuli-responsive engineered living materials, ELMs, are of interest due to their ability to actuate and display a physical response, which can be harnessed for application in soft robotics and bioremediation. Typically, stimuli-responsive ELMs have been prepared using a one-pot synthesis approach where living cells are incorporated into a monomer precursor solution followed by crosslinking. Here we synthesize a stimuli-responsive ELM using a new approach, diffusing cyanobacteria cells (Synechococcus elongatus PCC 7942) into a crosslinked thermo-responsive hydrogel, poly (N-isopropylacrylamide) (PNIPAm). We show that introducing living cells via diffusion creates a pseudo-bilayer and subsequent curvature change of the stimuli-responsive ELM as the cells proliferate. We anticipate that the understanding of cyanobacteria-PNIPAm system will spur the development of more advanced stimuli-responsive ELMs capable of complex actuation.

Funding Acknowledgement: This work was supported by the National Science Foundation through University of California San Diego Materials Research Science and Engineering Center (UCSD MRSEC), grant number DMR-2011924.