Nano Machining of Channels by Rubbing at Ultrasonic Frequency Under Control of Surface Fracture at Nano Scale

本计画的目的是提出一种超音波频率下的奈米研磨加工方法，并展示其奈米通道的制作能力与应用。主要研究结果如下：1.用于纳米加工的集中质量悬臂我们开发了一种独特的用于纳米加工的悬臂。悬臂在自由端的尖端上具有杆状质量。附加质量除了增加平移惯性外，还增加了惯性矩。在第二种弯曲振动模式下，悬臂的自由端由于附加质量的惯性而表现得像铰接端。尖端的垂直运动被压低，并且尖端围绕所附质量的重力中心旋转。尖端顶点横向振动，并且能够感测尖端顶点和样品表面之间的相互作用的剪切力。当附加质量的惯性矩比悬臂的惯性矩大4倍时，即使在尖端与样品表面接触的情况下，集中质量悬臂的动力学也变得与单自由度质量弹簧系统相同。这意味着集中质量悬臂梁在循环接触模式下使用时能够提供足够的摩擦力。通道的纳米加工虽然悬臂梁自由端的垂直运动被抑制，但偏转角度可以被检测到。循环接触的正常操作模式被施加到集中质量悬臂，其中剪切力被控制。我们展示了在树脂表面上制造具有几百纳米的宽度和几十纳米的深度的纳米通道。

The aim of this project is to present a method of nano machining by rubbing at ultrasonic frequency and to show the ability of fabrication of nano channels and the application. The results are summarized as follows:1. Concentrated-mass cantilever for nano machiningWe developed a unique cantilever for nano machining. The cantilever has a rod-like mass on the tip equipped at the free end. The attached mass enhances the moment of inertia in addition to the translational inertia. In the second mode of flexural vibration, the free end of the cantilever behaves like a pined end due to the inertia of the attached mass. The vertical motion of the tip is depressed and the tip rotates around the gravitational center of the attached mass. The tip apex vibrates laterally and is able to sense interactive shear force between the tip apex and a sample surface. When the moment of inertia of the attached mass is 4 times larger than that of the cantilever, the dynamics of the concentrated-mass cantilever becomes the same as that the one-freedom mass-spring system even in the case that the tip is bought into contact with a sample surface. This means that the concentrated-mass cantilever is able to provide sufficient rubbing force when it is used in the cyclic contact mode.2. Nano-machining of channelsAlthough the vertical motion of the free end of the cantilever is depressed, the deflection angle can be detected. The normal operation mode for cyclic contact was applied to the concentrated-mass cantilever, where the shear force was controlled. We demonstrated fabrication of nano channels with a width of a few hundreds of nanometers and a depth of a few tens of nanometers on a resin surface.