E. coli in Mazes

Bacteria often live in topologically complex environments. The path from a colony of bacteria which as exhausted its local supply of food to a source can have many branch points with false, dead-end leads. While chemotaxis can easily navigate bacteria to a food source in the presence of a food gradient, in a sufficiently complex and large maze chemotaxis will fail, leading to bacterial collapse at dead ends. Here, using nano and microfabrication, we made physical puzzles to study the collective behaviors of E. coli bacteria. We constructed mazes for bacteria to solve in order to get food and probed for their searching algorithms, with and without the presence of hydro flows.