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

将粉末颗粒置于三维空间中以制造微结构。本研究主要采用三种方法来制备磁性纳米结构：1）粒子间的火花等离子体焊接，2）静电力作用下的液滴，3）磁场作用下的磁性粒子自组装.粒子间火花等离子体焊接当在两个粒子之间施加高电压时，两个粒子被焊接。拉伸试验表明，颗粒间连接牢固。另一方面，粒子也可以通过焦耳加热连接。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诱导过程中建立连接。我们还开发了非常小的SPS粉末压制系统来制造微结构。在这个过程中，利用了上述实验中得到的脉冲电流的作用.通过静电力使用液滴利用细颗粒和液体的浆体来形成液滴。将浆料放入玻璃毛细管中，并在毛细管与基板之间施加高电压。液滴从毛细管的尖端飞到板上，在板上形成小的点。磁性粒子的磁场自组装磁性粒子在磁场中形成线状或柱状等结构。我们通过场来控制粒子的运动。将微结构填充到粘性橡胶中，并在橡胶固化后观察其结构。具有磁性颗粒结构的橡胶可用作微驱动器。

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.