Biocompatible and Reusable Synaptic Transistor With Efficient Electron-Ion Dynamic Coupling Interface

The development of bio-based synaptic transistors faces significant challenges. These arise from conflicting requirements between the hydrophilic ion interface and the polar nature needed for the channel interface. To address this, we introduced modification layers between the channel and bio-based pectin. Specifically, we employed a method that simultaneously regulates hydrophobicity and polarity, thereby optimizing the electron-ion coupling interface. Through a comprehensive analysis of interface polarity and surface energy characteristics, we identified poly(methyl methacrylate) (PMMA) as the optimal modification material. PMMA not only enhances proton permeation but also significantly improves electron transport. Consequently, synaptic transistors incorporating PMMA modification layers demonstrated a marked increase in post-synaptic response intensity. Furthermore, these devices successfully replicated a wide range of complex synaptic functions, including applications such as image display with low-frequency suppression and enhanced contouring. In addition to its performance-enhancing properties, the PMMA modification layer serves as a protective shield, ensuring stable synaptic signal output under mechanical bending conditions for over 10⁴ cycles. It also can maintain functionality throughout the cyclic degradation and replacement of ion interfaces. This research offers exciting potential for advancements in biocompatible and reusable electronics.