柔性低功耗感觉神经元器件的设计与系统集成研究

Learning from human somatosensory system on structure, function and working mechanism can provide continuous innovative ideas for developing new emerging flexible electronic systems with miniaturization, intelligence and integration. Electronic skin, which is flexible/stretchable as human skin and presents tactile sensing with high sensitivity, has become the research frontier and hotspot in the field of flexible electronics in recent years. However, most of the current research results focus on pressure detection, but do not explore to emulate the working mechanism and low-power characteristics of human somatosensory system, which will contribute to achieve real tactile perception for electronic skin. This project will draw lessons from the biological sensory neuron model, and proposes to develop a flexible and low-power sensory neuron system which is suitable for high density integration. Firstly, tactile sensors with high sensitivity and linear response in a wide range of pressure will be obtained by using GaN nanowires, device stack structure and micro-structure design. Secondly, threshold switching oscillators with high nonlinearity, small threshold voltage and low leakage current will be achieved by optimizing the parameters of Ag nanomaterials, based on device working mechanism. Finally, the flexible low-power sensory neuron system will be constructed by integrating with tactile sensor and threshold switching oscillator above, and the force/frequency transduction mechanism will be explored. From the perspective of device level, give prospects to the future application and development in artificial intelligence (AI) fields such as bionic robots and intelligent prostheses.

借鉴人体躯体感觉系统的结构、功能和工作机制，能够为研制微型、智能和集成化的新型柔性电子系统提供源源不断的创新思路。电子皮肤（Electronic Skin）具有人体皮肤一般的柔韧性，还具备高灵敏触觉探测功能，成为了近年来柔性电子领域的研究前沿与热点。然而，目前研究大多聚焦于压力信号探测，并未深入探究模仿躯体感觉系统的工作模式及低功耗特征，以使电子皮肤获得真正的触觉感知。本项目将借鉴生物感觉神经元模型，拟研制适于高密度集成的柔性低功耗感觉神经元系统。利用GaN纳米线、器件叠层结构及微结构设计，制备在较大压力范围内具有高灵敏度和线性响应的触觉传感器；从器件工作机制出发，优化调控Ag纳米材料参数，制备具有高非线性比、低阈值电压和低漏电流特性的阈值开关振荡器；将上述两种器件在柔性/弹性基底系统集成，构建柔性低功耗感觉神经元系统，探究力/频率转导的工作模式，从器件层面探索未来人工智能领域的发展。

触觉感知系统是目前人工智能领域亟需发展的重要方向之一，在仿生机器人、人机界面接口、生物神经元交互等有着广阔的应用前景。借鉴生物感觉神经元工作模式，本项目围绕新型柔性低功耗感觉神经元器件的设计和系统集成研究，着重解决了器件设计、系统集成、动态特性调控等关键难题。本项目顺利完成了预期的研究内容和目标，取得的主要成果有：（1）利用化学气相沉积法合成了竹节状GaN压电半导体微纳米线，发展了柔性接触转移工艺，构筑了新型柔性触觉感知器件，获得了较高灵敏度（GF=736）、突触特性等功能。（2）探索了Ag纳米线与聚二甲基硅氧烷（PDMS）复合薄膜的可控制备方法，构筑了具有较低操作电压和极低漏电流的非线性阈值开关柔性振荡器（神经元器件）；结合低温测试、仿真模拟等手段分析了Pt/Ag nanodots/HfO2/Pt基神经元器件的工作机制及自激振荡模式。（3）通过将柔性触觉传感器和振荡器进行系统集成，构筑了柔性低功耗感觉神经元系统，实现了压力-频率转导的工作模式，并优化了器件的设计方法及系统集成工艺，以及展示了神经反射弧启发的智能功率器件。项目执行期间，在Nature Communications、Nano Letters等权威期刊发表标注基金支持的SCI论文20篇（其中影响因子10以上11篇）、国际会议EI论文2篇，申请专利2项，撰写学术专著1章；应邀在国际/国内学术会议或线上研讨会做邀请报告6次；培养博士后1名（已出站）、博士/硕士研究生11名（已毕业7名）。