面向微纳机器人的等离激元瞬态高能汽泡驱动方法研究

驱动技术是微纳机器人研究的核心，是实现其可控运动的前提和基础。本项目拟以申请人前期研究中发现的新型瞬态高能蒸汽泡——等离激元初始汽泡为驱动载体，利用其高效的光汽转换效率、超快的生长速度、优异的可调控性实现微纳机器人的高效驱动。为此，本项目拟以固液界面热生成和热传导理论为基础，通过探究激光照射表面后温度场分布规律，结合液汽相变理论和超时间分辨率实验观测，揭示等离激元初始汽泡成核机理，建立其生长动态理论模型。在此基础上，综合运用理论建模、多物理场数值仿真、微粒子测速和超高精度力测量等实验手段，以汽泡驱动力产生机理揭示为前提，以气泡成核过程中光-热-机械能转化机制探究为指导，以低雷诺数下机器人流固耦合动力学建模为支撑，以汽泡尺寸、生成频率和激光作用点位置控制为调控手段，实现快速、高效、灵活的微纳机器人运动控制，建立一种基于等离激元初始汽泡的微纳机器人驱动技术，对现有技术进行有效补充。

Investigation of the driving methods for micro-nano robots is important to achieve the controllable motion of robots. In this project, we intend to apply a recently observed explosive plasmonic vapor bubbles to achieve high-speed driving of the micro-nano robots. The plasmonic vapor bubbles, which are discovered in our previous study, have a high light-vapor conversion efficiency and ultra-fast growth rate, and are easy to be controlled. Here we will first study the spatial and temporal evolution of water temperature under laser irradiation in the vicinity of solid liquid interfaces. Furthermore, the nucleation mechanism of the plasmonic bubbles will be revealed and a theoretical model of the bubble growth dynamics will be established. With this, we will further investigate the mechanism of bubble induced propulsion. This can be achieved by theoretical modeling, numerical simulation of multi-physical field, PIV measurement and high precision force measurement. We will also investigate the mechanism of energy conversion, from optical to thermal, and from thermal to kinetic. After that, a fluid-solid coupling kinetic model will be built up to describe the motion characteristics of vapor bubble driven robots. With the model, the motion control of robots will be experimentally implemented by tuning the generation of vapor bubbles, regarding size, nucleation frequency, and laser irradiation position. This driving method is flexible with very high propulsion efficiency, which is believed to be a good option to the current robot driving techniques.