Many microbial cells form biofilms as a means of survival. Biofilms are formed when a large number of microbial cells aggregate together. This year, the UCSF iGEM team has engineered artificial biofilms via yeast cell surface display. We synthetically engineered S. cerevisiae to form tunable biofilm-like structures by inducing the display of adhesive proteins on their surface. By combining the natural yeast mating receptors – Aga1 and Aga2 – with adhesive proteins from a variety of organisms, we created several adhesive interactions among yeast cells. Our synthetic cell adhesions can serve as a model for biofilm formation and primitive multicellular structures.