Ionic Gel-Based Somatosensory Neuromorphic Device with Diverse Neuronal Spiking Behaviors

The development of neuromorphic devices that emulate the sensory and processing capabilities of the human somatosensory system is of significant interest for neuro-robotics and medical devices. Here, we present an iontronic somatosensory neuromorphic device that shows various neuronal spiking behaviors in response to tactile and thermal stimuli by utilizing ion gel-based capacitive artificial receptors and threshold switching devices. The capacitance of the ionic artificial receptor varies with mechanical and thermal stimuli. It controls the switching dynamics of the threshold switching device, thereby regulating the frequency and pattern of the spiking voltage signals of the somatosensory neuromorphic device. Moreover, the capacitive artificial receptors exhibit various time-dependent responses, leading to diverse tactile response characteristics. A soft iontronic somatosensory neuromorphic device composed of a simple circuit with a capacitive sensor and the switching device can be combined with spiking neural networks for recognizing complex stimuli. We envision that the iontronic somatosensory neuromorphic device with various spiking dynamics holds great promise for multifunctional neuromorphic tactile systems.