Touchable gustatory sensing

The integration of technologies such as human-machine interfaces and biomimetic intelligent robots has brought about a unique revolution in modern science and technology, recognized as one of the most promising and critical frontier technologies. In the construction of smart robots, sensors are the most crucial units, second only to processor chips in importance. Robots equipped with various supplementary sensors can receive commands and perceive the external environment. Among these, tactile perception is an essential sensory function in which human skin directly interacts with the external environment. This perception arises from the coordinated responses of subcutaneous mechanoreceptors and neurons to different environmental stimuli, as well as the brain’s recognition of incoming signals through neural fibers

The 2021 Nobel Prize in Physiology or Medicine was jointly awarded to David Julius and Ardem Patapoutian for their discovery of temperature and touch receptors. Tactile perception in human skin is a mechanotransduction process where mechanical stimuli activate ion channels, converting stress stimuli into electrophysiological signals.3 David Julius identified the capsaicin receptor in human skin. Capsaicin, the spicy component of chili peppers, selectively activates sensory neurons to evoke a burning pain sensation. At the biomolecular level, touch and taste share the same mechanistic model of activating ion channels. Tactile sensation, as the most primitive sense in microorganisms, is combined with taste. Organisms perceive the external environment, including temperature, chemicals, and morphology. Today, tactile sensation with gustatory elements provides richer and more significant biological information at the molecular and ionic levels, applicable in health monitoring, clinical diagnostics, and human-machine interactions.