Artificial Reflex Arc: An Environment-Adaptive Neuromorphic Camouflage Device

Cephalopods can swiftly merge into the surroundings by changing their skin color even without the involvement of brains. Inspired by this ability, we designed a tunable, environment- adaptive camouflagic artificial reflex arc that can independently activate electrochromism in response to optical stimuli. The receptor of this arc consists in a light-stimulated synaptic transistor (LSST) that also performs synaptic functions, e.g., excitatory post-synaptic current (EPSC) generation, paired-pulse facilitation (PPF), high-pass filtering, and modulation. Amplified EPSC causes color transform of an electrochromic device (ECD) upon external optical stimuli. We emulate the phenomenon that an octopus changes color according to the background light with or without intentional modulation to demonstrate the camouflage effect of our device.