Unlike most man-made machines, which rely on centralized “engines”, biological organisms convert energy to motion in a highly distributed fashion: macroscopic forces emerge from the coordinated actions of many chemically powered, molecular scale actuators. Distributed energy conversion in biology offers several advantages (robust to failure, tunable actuation, complex deformations, etc.) that motivate the pursuit of non-biological, colloidal machines, in which energy is harnessed at colloidal scales to produce emergent behaviors at the mesoscale and perform useful functions at the macroscale. To realize these capabilities, we aim (1) to develop efficient mechanisms of energy conversion to enable distributed actuation in colloidal materials; (2) to understand and ultimately design the collective dynamics of many interacting, colloidal motors; (3) to harness these dynamic behaviors within artificial systems to perform useful functions. As part of the Center for Bio-Inspired Energy Science (CBES) – a DOE-funded Energy Frontier Research Center at Northwestern University – our contribution focuses on the development of active colloidal systems with which to investigate collective, non-equilibrium dynamics. Building on recent advances in the study of self-propelled colloids, we are exploring the dynamics of particles subject to active rotational motion and how it depends on particle shape and connectivity, hydrodynamic and colloidal interactions, as well as spatiotemporal variations in energy input. This experimental effort is supported by theory and simulations performed both within our group and by our collaborators (Sharon Glotzer, U. Mich).
M. Spellings, D. Klotsa, M. Engel, S. Sabrina, A.M. Drews, N.H.P. Nguyen, K.J.M. Bishop*, S.C. Glotzer*, Shape control and compartmentalization in active colloidal cells. Proc. Natl. Acad. Sci. U.S.A. 112, E4642–E4650 (2015) [Highlight in Nature Physics]
S. Sabrina, M. Spellings, S.C. Glotzer*, K.J.M. Bishop*, Coarsening dynamics of binary liquids with active rotation. Soft Matter 11, 8409-8416 (2015) [cover art]
