A low-power stretchable neuromorphic nerve with proprioceptive feedback

• Published in: Nature biomedical engineering Vol. 7; no. 4; pp. 511 - 519
• Main Authors: Lee, Yeongjun, Liu, Yuxin, Seo, Dae-Gyo, Oh, Jin Young, Kim, Yeongin, Li, Jinxing, Kang, Jiheong, Kim, Jaemin, Mun, Jaewan, Foudeh, Amir M., Bao, Zhenan, Lee, Tae-Woo
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.04.2023; Nature Publishing Group
• Subjects: 639/301/1005/1007; 639/301/923/1028; Animals; Artificial muscles; Bioengineering; Biomedical and Life Sciences; Biomedical engineering; Biomedical Engineering/Biotechnology; Biomedicine; Carbon nanotubes; Cortex (motor); Disorders; Electrodes; Electronics; Engineering; Feedback; Feedback, Sensory; Hydrogels; Injuries; Mice; Motor Neurons; Movement disorders; Muscle spindles; Muscles; Nanotechnology; Nanotubes, Carbon; Nanowires; Nerves; Nervous system; Neural prostheses; Neurological diseases; Neurology; Neuromorphic computing; Patients; Power management; Proprioception; Prosthetics; Quality of life; Rehabilitation; Sensors; Signal processing; Spinal cord; Spinal cord injuries; Synapses - physiology; Transistors
• ISSN: 2157-846X; 2157-846X
• DOI: 10.1038/s41551-022-00918-x

By relaying neural signals from the motor cortex to muscles, devices for neurorehabilitation can enhance the movement of limbs in which nerves have been damaged as a consequence of injuries affecting the spinal cord or the lower motor neurons. However, conventional neuroprosthetic devices are rigid and power-hungry. Here we report a stretchable neuromorphic implant that restores coordinated and smooth motions in the legs of mice with neurological motor disorders, enabling the animals to kick a ball, walk or run. The neuromorphic implant acts as an artificial efferent nerve by generating electrophysiological signals from excitatory post-synaptic signals and by providing proprioceptive feedback. The device operates at low power (~1/150 that of a typical microprocessor system), and consists of hydrogel electrodes connected to a stretchable transistor incorporating an organic semiconducting nanowire (acting as an artificial synapse), connected via an ion gel to an artificial proprioceptor incorporating a carbon nanotube strain sensor (acting as an artificial muscle spindle). Stretchable electronics with proprioceptive feedback may inspire the further development of advanced neuromorphic devices for neurorehabilitation. A stretchable neuromorphic ‘nerve’ restores coordinated and smooth motions in the legs of mice with neurological motor disorders, enabling the animals to kick a ball, walk or run.