Touch and see: Physical interactions stimulating patterns in artificial cephalopod skin

Abstract

Cephalopods (e.g., octopus, squid and cuttlefish) employ their colour-changing skin for rapid active camouflage and signalling in complex visual environments. This is achieved through the collective embodied intelligence of chromatophores: pigment organs which stretch under electrical stimulation to affect local skin colouration, and are also responsive to physical stimulation. In this study, we present an experimental investigation of touch-responsive bioinspired artificial cephalopod skin fabricated from soft dielectric elastomer, a material that has the potential to mimic the actuation of biological chromatophore cells in both speed and optical modulation. We measure the behaviour of an interacting cyclic network of such artificial chromatophores, using local strain as the control input that drives cell actuation. By applying simple local feedback rules analogous to cellular automata, we demonstrate that physical stimulation can generate a variety of travelling wave-like patterns that mimic those seen in biological cephalopod skins.