When metal nanoparticles are functionalized with charged ligands, the movement of counterions and conduction electrons is coupled, which enables us to develop electronic devices, including diodes, transistors, and logic gates, but dynamically modulating the conductivity of a synaptic device within these materials has proved challenging. Here we show that an artificial synapse can be created from thin films of functionalized metal nanoparticles using an active silver electrode. The electric-field-injected Ag⁺ coordinates with carboxyl ligands that sets up a conduction bridge to increase the nanoparticle conductivity by reducing the electron tunneling/hopping energy barriers. The dynamic modulation of conductivity allows us to implement several important synaptic functions such as potentiation/depression, paired-pulse facilitation, learning behaviors including short-term to long-term memory transition, self-learning, and massed leaning vs spaced learning. Finally, based on the nonvolatile characteristics, the metal nanoparticle synapse is used to build a single-layer hardware spiking neural network (SNN) for pattern recognition.

中文翻译：

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场创建的坐标阳离子桥使金属纳米粒子内的电导调制和人工突触成为可能

当金属纳米粒子被带电配体功能化时，反离子和传导电子的运动是耦合的，这使我们能够开发电子设备，包括二极管、晶体管和逻辑门，但动态调节这些材料中突触设备的电导率已被证明具有挑战性的。在这里，我们表明可以使用活性银电极从功能化金属纳米颗粒的薄膜中创建人工突触。电场注入 Ag ⁺与建立传导桥的羧基配体配合，通过减少电子隧穿/跳跃能垒来增加纳米粒子的导电性。电导率的动态调制使我们能够实现几个重要的突触功能，例如增强/抑制、配对脉冲促进、学习行为，包括短期到长期记忆转换、自学习和集中学习与间隔学习。最后，基于非易失特性，利用金属纳米粒子突触构建单层硬件脉冲神经网络（SNN）进行模式识别。