A Microcapsule System That Mimics Heptotactic Cells

Biological cells can signal to each other using biomolecules, and this signaling acts as a cue for motion. Often, this motion is driven by adhesion gradients on the substrate where the cells are located. In this work, it is shown that synthetic microcapsules, encapsulated with nanoparticles, can mimic cell behavior. The nanoparticles can act as 'signals', which modulate the adheshion gradient of the substrate on which the microcapsules are located, leading to autonomous motion of the microcapsules. Simulations and analysis of this system yield several interesting results. For a train of N microcapsules moving at a velocity U, we show that U~N^-1/2. Also, results on collective behavior of a system of microcapsules in 3D is presented.