Tactile sensory synapse based on organic electrochemical transistors with ionogel triboelectric layer

• Published in: Nano energy 2024-12, Vol.131, p.110202, Article 110202
• Main Authors: Sultan, M. Junaid, Bag, Atanu, Hong, Seok Ju, Wang, Guangyu, Kumar, Surjeet, Chouhdry, Hamna Haq, Lee, Nae-Eung
• Format: Article
• Language: English
• Subjects: Artificial mechanoreceptor; Organic electrochemical transistor; Slow adapting; Synapse-like function; Triboelectric coupling
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2024.110202

Recent advancements in artificial tactile sensory systems have significantly improved their ability to replicate the sensory functions of biological systems by integrating various sensory and synaptic components, yet these configurations often lack the efficiency and seamless integration seen in nature. To address these limitations, we introduce a monolithic artificial mechanoreceptor that combines an organic electrochemical transistor with an ionogel (IG), serving as both a mechano-responsive triboelectric sensing layer and a gate electrolyte. Triboelectrification upon mechanical stimulation using different materials produces an output voltage of the triboelectric generator which drives the movement of ions within the tribo-negative IG based on 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid and poly(vinylidene fluoride-co-hexafluoropropylene), modulating de-doping of the poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) channel. This enhances synaptic functionalities such as spike number-dependent plasticity (SNDP) and spike duration-dependent plasticity (SDDP) during mechanical stimulation, allowing the device to mimic biological mechanoreceptors by sensing and converting external mechanical signals, including the number, force, and duration of touches, into synaptic plasticity. Furthermore, the device shows potential for material recognition using machine learning techniques, marking a significant advancement towards efficient artificial tactile systems. [Display omitted] •Monolithic mechanoreceptor integrates TENG and OECT for efficient tactile sensing.•Ionogel serves as tribo-sensing layer and gate dielectric, simplifying the structure.•Device mimics biological functionalities, converting mechanical signals into memory.•Triboelectric transduction enables material recognition using machine learning.•Simplified architecture enhances power consumption and data handling.