Researchers from Stanford University in the United States and Seoul National University in South Korea have developed an artificial sensory nervous system that can activate the twitching reflex in cockroaches and recognize Braille letters. The related article was recently published in the journal *Science*. This work, creating artificial skin for prosthetics, is a first step in restoring sensation to amputees and may one day provide robots with some reflexive abilities.
This achievement mimics how the skin stretches and repairs itself. Like an intelligent sensory network, it not only knows how to transmit pleasant sensations to the brain but also knows when to command muscles to make timely, reflexive decisions. Zhenan Bao, a professor of chemical engineering at Stanford University and one of the paper's senior authors, said that the skin is a complex sensing, signaling, and decision-making system, and artificial sensory neural systems are a key step in creating skin-like sensory neural networks for various applications.
This paper describes an artificial sensory neural circuit that can be embedded in skin-like coverings for future neural prosthetic devices and soft robots. It integrates three key components: a touch sensor capable of detecting minute external pressure; flexible electronic neurons that can emit signals; and artificial synaptic transistors that sense signal stimuli. The biological synapses transmit signals and store information for simple decisions, while the synaptic transistors perform these functions within the artificial neural circuit.
The team tested the system's ability to generate reflexes and tactile sensations. In one test, they attached an artificial nerve to a cockroach's leg and applied minute increments of pressure to a touch sensor. The electronic neuron converted the sensor signal into a digital signal and transmitted it through a synaptic transistor, causing the cockroach's leg to twitch more or less violently as the pressure on the touch sensor increased or decreased. In another test, the artificial nerve was also able to distinguish Braille letters.
