基于LiNbO3:Pr3+单晶薄膜应力发光性能的电子皮肤触觉传感器

Electric skin is a kind of artificial flexibility electronic device, which can simulate human tactile sense via electronic methods. Electric skin is widely applied in artificial intelligence, wearable device and skin repairing fields. The electric skin should detect a very weak pressure as well as the pressure distribution, which been brought into research focus internationally. In this proposal, the novel tactile sensor is designed as the 3D structure of ZnO nanorods-LiNbO3:Pr3+-Substrate, where the advantageous mechanouminescence of the Pr3+ doped LiNbO3 (LiNbO3:Pr3+) single-crystal film works as the pressure-detection medium, and the single ZnO nanorod as a pixel. As the key material, the LiNbO3:Pr3+ crystal with different Li/Nb ratio will be obtained through Czochralski method. Then the 300-nm thick LiNbO3:Pr3+ single-crystal film on SiO2 substrate will be prepared through commercial milling technique from LiNbO3:Pr3+ wafer. This study will provide an understanding of the mechanism of mechanouminescence for LiNbO3:Pr3+ as well as the regulation mechanism of Li/Nb ratio to the luminescence intensity. Moreover, the interaction of piezoelectric effect between ZnO nanorods and LiNbO3:Pr3+ single-crystal film will be understood. After building the function relationship between luminescence intensity and pressure, the tactile sensor for electric skin will be finally achieved with high sensitivity and high resolution.

电子皮肤是一种用于实现仿人类触觉感知功能的人造柔性电子器件，在人工智能、可穿戴设备和皮肤修复医学等领域具有广阔的发展空间。电子皮肤首先要具备辨别细微压强及其分布的触觉功能，具有高灵敏触觉系统的电子皮肤是当今国际上最热门的前沿研究领域之一。本研究以新型压光模式的触觉传感器为主要目标，以掺Pr3+铌酸锂单晶薄膜应力荧光为压力探测媒介，以图案化ZnO纳米柱阵列作为压力发光触发点，构建“纳米阵列/应力发光薄膜/衬底”三维结构器件。在关键材料制备技术上，通过温场优化设计实现不同Li/Nb配比掺Pr3+铌酸锂晶体的生长技术；研究掺Pr3+铌酸锂的应力发光机理，明确单晶薄膜应力发光过程中力-电-光三种物理信号的相互作用关系；通过研究ZnO在柔性衬底上成核和生长机制，实现图案化ZnO纳米柱阵列制备技术，进而研究ZnO纳米柱压电效应对于单晶薄膜应力发光的压电增强效应，实现高分辨率、高灵敏性的触觉传感技术。

铌酸锂拥有特殊的缺陷结构，可以通过元素掺杂、晶体组分等调控途径改进或者引进特定的物理性质，其中激活离子掺杂铌酸锂具有优秀的光谱性质，被广泛运用于光学器件。本项目主要研究了3英寸掺镨铌酸锂晶体的生长机制及其光学性能，首次实现了3英寸掺镨铌酸锂晶体的生长。并实现了3英寸钕镁双掺铌酸锂晶体的生长，研究了钕镁双掺铌酸锂晶体的周期极化机理，搭建了小型化自光参量振荡器，首次实现了瓦数级中红外激光输出。研究了8英寸钕镁双掺铌酸锂晶体的生长机制，形成相对应的独立自主的知识产权，并已完成产业转化。传感器方面，实现了ZnO纳米柱阵列制备并倒模出基于PMMA/CNTs材料的纳米微孔阵列，搭建了16像素触觉传感器件，明确了柔性非对称薄膜在触觉传感器作用机理，利用这种非对称薄膜建立了具有16像素触觉感应电子皮肤的4×4压阻矩阵系统，实现了包含压力点的空间和时间分辨率的四维分辨率。