Before revision:  To generate and manipulate these micron-scale structures and force fields , cells create spatiotemporal patterns of molecular-scale activity ] ]  ] . Here, we control micron-scale structures and fluid flow by manipulating molecular-scale protein activity set by dynamic optical boundaries in an engineered system of purified proteins .
After revision:  To generate and manipulate these micron-scale structures and force fields , cells create spatiotemporal patterns of molecular-scale activity ] ] ] . Here, we control micron-scale structures and fluid flow in an engineered system of purified proteins .