Capture of particles by a flexible granular envelope

The capture of small particles by a flexible envelope can model many common phenomena. For example, in the rotating environment of a commercial dryer, large, flexible, non-convex objects like fitted sheets and duvet covers often capture smaller items like socks that fail to dry as a result. Amoeba exploit a similar process for prey capture by extruding pseudopodia in which smaller organisms become trapped. We have developed a quasi-2D granular system with qualitatively similar dynamics: a granular chain envelope composed of custom ball chain in a background dispersion of spherical grains inside a rotating drum. The particle-scale geometry of the granular chain determines the available conformations of the envelope, leading to a biased convexity. We share the results of our investigation of the kinetics of particle capture for this novel model system.