Development of Three-dimensional Micro/nano Fabrication Process with Particulate Materials

将粉末颗粒置入三维空间，形成微结构。本研究采用三种方法制作结构：1)颗粒间的火花等离子焊接，2)静电作用下的熔滴，3)磁性颗粒中的磁场自组装1。颗粒间的放电等离子焊接当两个颗粒之间施加高压时，两个颗粒被焊接。通过拉伸试验发现，颗粒之间是紧密相连的。另一方面，粒子也可以通过焦耳加热连接在一起。然而，在这种情况下，这种联系并不那么强烈。介绍了如何在脉冲电流感应过程中建立连接关系，并开发了超小型SPS粉末压制系统来制备微结构。在这个过程中，利用了从上述实验中获得的脉冲电流的效果。利用静电力使用液滴利用细小颗粒和液体的混浊来形成液滴。将浆料放入玻璃毛细管中，在毛细管和基板之间施加高压。液滴从毛细管末端飞到平板上，在平板上形成小点。磁性粒子中的磁场自组装磁性粒子在磁场中形成线状或柱状等结构。我们用场来控制粒子的运动。将微观结构填充到粘性橡胶中，固化橡胶后观察结构。具有磁性颗粒结构的橡胶可用作微执行器。

Powder particles are set into three-dimensional space to fabricate micro structure. Three approaches are employed to make structures in the present study as following, 1) Welding by spark plasma between particles, 2) Using droplets by electro-static force and 3) Self-assembling by magnetic field in magnetic particles.1. Welding by spark plasma between particlesTwo particles are welded when high voltage is applied between them. It is found by tensile test that the particles are connected strongly. The other hand, the particles could be also connected by Joule heating. However, the connection is not so strong in this case. It is shown how to establish the connection during pulse current induced process.We also develop very small SPS powder compaction system to fabricate micro structure. In this process, the effect of the pulse current obtained from above experiment is utilized.2. Using droplets by electro-static forceSlurry of fine particles and liquid are utilized to make a droplet. The slurry is put into glass capillary and high voltage is applied between the capillary and a base plate. The droplet fly to the plate from the tip of the capillary to fabricate small dots on the plate.3. Self-assembling by magnetic field in magnetic particlesThe magnetic particles form structures such as line or columnar pattern in the magnetic field. We control the movement of the particles by the field. The micro structure is filled into the viscous rubber and after solidified the rubber the structure is observed. The rubber with the magnetic particles' structure can be used as a micro actuator.