Fig. 1: Artificial system in comparison with the biological somatosensory system.

a The biological somatosensory system that is stimulated by external tactile information. Pressure applied onto the mechanoreceptors in the skin can initiate action potentials. The action potentials will be transferred by afferent nerves and combined through the synapse. Afterward, the information will be processed by CNS and transferred to the brain to feel the pain, and at the same time, an action potential will be transmitted to the effector through the efferent nerve to trigger the body’s feedback to avoid further injury. b An artificial somatosensory system that mimics the biological pain perception systems composed of several main components.