J2240102 弾性表面波を用いた粉体フィーダーの提案([J224-01]『マイクロ・ナノ機械の信頼性』のための材料創製・測定・解析技術 ナノ構造加工・プロセス)

Abstract

In order to operate dry micro powder, we propose a powder feeder driven by surface acoustic wave (SAW). The powder feeder consists of one interdigital transducer (IDT) and two triangular guide walls. The IDT has 20 electrode pairs, a pitch size of 400 μm, and an aperture width of 5 mm, while the guide wall, located at an inclination angle of 5° against the central axis of the IDT, has a length of 35 mm and a minimum 300-μm interval between walls. The IDT and the guide walls are made of a 1-μm Al layer and were fabricated on a piezoelectric wafer (127.8-degree y-rotated x-propagating LiNbO_3) by one photolithography process. To investigate characteristics of the powder feeder, we carried out a transport experiment by using copper powder whose particle size was about 10 μm. As a result, when a signal of 31.6-MHz radio frequency was applied to the IDT, the powder was gradually collected during transport to the opposite side of the IDT until the powder particles arrived at the substrate edge one after the other and fell down through the narrow part between the guide walls. This result demonstrates that, by arranging the guide walls, the powder can be accurately poured down a target point.