Abstract

Dynamic assembly, self-organization and motion is a common phenomenon in living systems. Artificial systems that mimic this behavior are currently a research area of intense activity. The goal is to realize systems that can move and exhibit the complex self-organization found in natural systems. Symmetry-breaking appears to be a pre-requisite for achieving many interesting functions including locomotion, but is in general difficult to realize with most colloidal and molecular systems. I will discuss how one can nevertheless obtain motion in molecular and chemically-active colloidal systems. A fabrication process is described that permits us to obtain large numbers of designer micro- and nanostructures with defined shape and material composition. These enable a number of applications, including as nanopropellers that can penetrate biological tissue, and as self-propelled autonomous chemical nanomotors. Whether enzymes can also self-propel is currently being debated and I will discuss recent diffusion measurements that address this question. Finally, it is shown that a recent advance in the generation of complex ultrasound fields promises “one shot” assembly of soft-matter into arbitrary shapes.