The Role of Ionic Liquids at the Biological Interfaces in Bioelectronics

The growing demand for personalized healthcare and neurophysiological monitoring is accelerating the advancement of intelligent bioelectronic technologies capable of interacting precisely with biological systems. The human body, as a complex multicellular organism, performs diverse and regulated physiological functions. These biological systems rely on tightly regulated ion-based mechanisms to respond to stimuli, perceive sensory inputs, and maintain homeostasis. The human nervous system operates as a biologically optimized information processing network with remarkable energy efficiency and adaptability. Efforts to artificially replicate such physiological mechanisms have become a central focus in the development of bioelectronics that establish precise ion-based interactions with living tissues. Accordingly, this review highlights ionic liquids (ILs) as artificial ionic materials that play a pivotal role in bridging ion-based signal transmission in biological systems with the electron-based operation of electronic devices. To realize integrated and multifunctional interfaces capable of engaging with a wide range of biological tissues, a comprehensive understanding of the composition-structure-function relationships and elucidation of the precise working mechanisms of ILs is imperative. Through this, ILs may evolve beyond their traditional role as electrolytes into core platform materials for bioinspired electronic systems that integrate sensing, actuation, and adaptive intelligence.