Getting a grip on touch receptors

A synchronized event-cue feedback loop integrating a 3D printed wearable flexible sensor-tactor platform

Wearable devices designed for the somatosensory system aim to provide event-cue feedback electronics and therapeutic stimulation to the peripheral nervous system. This prompts a neurological response that is relayed back to the central nervous system. Unlike virtual reality tools, these devices precisely target peripheral mechanoreceptors by administering specific stimuli. Given variations in mechanoreceptor density and type across different body locations, adaptable flexible electronics are essential for effective targeting. Here, we develop a sensing-actuation platform using advanced manufacturing techniques. This platform seamlessly integrates custom flexible silicone-based actuators with carbon nanotube (CNT)-elastomer tactile sensors, enabling wearable electronics to deliver responsive feedback. By optimizing the cantilevers of the actuators, these tactors can achieve a broad spectrum of driving frequencies. Three functional, synchronized event-cue feedback devices-a prosthetic, sole, and glove-are presented, demonstrating their capability to utilize CNT sensors for detecting pressure variations from weight, gait, and grip, and transmit signals to flexible tactors, eliciting vibrotactile cues. The deployment of these innovative devices holds promise for stimulating peripheral nerves, augmenting prosthetic functionality, and enhancing grip control and tactile sensation in individuals with limited nervous system function.

Bionic Recognition Technologies Inspired by Biological Mechanosensory Systems

Mechanical information is a medium for perceptual interaction and health monitoring of organisms or intelligent mechanical equipment, including force, vibration, sound, and flow. Researchers are increasingly deploying mechanical information recognition technologies (MIRT) that integrate information acquisition, pre-processing, and processing functions and are expected to enable advanced applications. However, this also poses significant challenges to information acquisition performance and information processing efficiency. The novel and exciting mechanosensory systems of organisms in nature have inspired us to develop superior mechanical information bionic recognition technologies (MIBRT) based on novel bionic materials, structures, and devices to address these challenges. Herein, first bionic strategies for information pre-processing are presented and their importance for high-performance information acquisition is highlighted. Subsequently, design strategies and considerations for high-performance sensors inspired by mechanoreceptors of organisms are described. Then, the design concepts of the neuromorphic devices are summarized in order to replicate the information processing functions of a biological nervous system. Additionally, the ability of MIBRT is investigated to recognize basic mechanical information. Furthermore, further potential applications of MIBRT in intelligent robots, healthcare, and virtual reality are explored with a view to solve a range of complex tasks. Finally, potential future challenges and opportunities for MIBRT are identified from multiple perspectives.