Three-dimensional nanofabrication system for laser-driven micromachines

我们尝试利用波导上产生的倏逝场辐射力来驱动某些类型的微机械。1）微运动器辐射力的分析和微运动器的设计我们建立了计算辐射力的方法。我们的方法基于边界元法（BEM）和扩展的米氏理论。利用该方法对能有效地将光能转化为微驱动器动能的微驱动器的形状和折射率进行了检测。计算结果表明，当微驱动器的相对折射率大于1.5时，利用光的共振效应可以提高能量传递效率。2）紫外光固化树脂微驱动器的制作我们发展了一种三维微细加工技术，用于制作各种类型的微驱动器。在制造技术中，UV固化树脂的三维体积中的点通过近红外激光束的双光子吸收过程光聚合。可以通过扫描近红外激光束的聚焦点来制作3D结构。3）微位移器的驱动实验利用槽形波导上产生的倏逝场驱动了几种微位移器。我们使用的微移动器是直径为1- 5 μ m的电介质和金属颗粒。所用光源为Nd：YLF激光器，其振荡波长为1047 μ m。在实验中，粒子被捕获在波导上产生的倏逝场的范围内，并沿波导沿着纵向运行。其运动速度和距离分别接近每秒10微英寸和超过1厘米。

We tried to use the radiation force from the evanescent field, which is generated on the waveguide, for driving some kinds of micromachines.1) Analysis of the radiation force generated for micro-movers and design of micro-moversThe methods for calculating the radiation force were established by ourselves. Our methods base on boundary element method (BEM) and extended Mie's theory. The shape and refractive index of a micro-mover, which can transfer the energy of light to the kinetic energy of micro-mover efficiently, were examined by the methods. The calculation results showed that the efficiency of the energy transfer can be increased by using the resonance effect of light in case that the relative refractive-index of a micro-mover is greater than 1.5 approximately.2) Fabrication of a micro-mover with UV-cured resinWe developed a three-dimensional microfabrication technique in order to make some kinds of micro-movers. In the fabrication technique, a point in three-dimensional volume of UV-cured resin is photopolymerized through two-photon absorption process with a near-IR laser beam. A 3-D structure can be made by scanning the focused point of the near-IR laser beam. The resolution of our system have attained 1 mum nearly.3) Experiments on drive of micro-moversWe drove some kinds of micro-movers with the evanescent field generated on the channeled waveguide. The micro-movers we used are dielectric and metal particles whose diameter is 1-5mum. The light source we used is Nd : YLF laser whose oscillating wavelength is 1047mum. In the experiments, particles were trapped within the extent of the evanescent filed generated on the waveguide, and longitudinally ran along the waveguide. The velocity and the distance of the movement were near ten microins per second and over 1 cm, respectively.