講演抄録/キーワード |
講演名 |
2009-12-18 13:30
円形振動板による微小物体の非接触空中周回搬送 ○小山大介・伊藤 裕・中村健太郎(東工大) US2009-80 |
抄録 |
(和) |
円形振動板を用いた超音波による微小物体の非接触周回搬送について検討した.著者らはこれまでにたわみ振動板と反射板による微小物体の直線非接触搬送について報告した.振動板反射板間に格子状の音響定在波を励振することにより,その音圧節部に粒子を捕捉,操作することが可能である.本報告では円軌跡を伴う粒子の非接触周回搬送を検討した.厚さ0.5 mm,直径30 mmのアルミニウム製振動板に厚さ0.5 mmのリング型PZT素子を接着した.FEA結果より,周波数47.8 kHzにおいて節円数1,節線数3のたわみ振動モードを励振させるため,PZT素子の電極を24分割した.振動板反射板間に音響定在波を励振させるため,振動板と同形状のアルミニウム製円形反射板を振動板と平行に距離5 mmの位置に設置した.FEAより振動板反射板間の音圧分布を計算し,微小剛体球に働く音響放射力を計算し,その捕捉位置を予測した.設計に基づいた試作機を用いた実験より,直径数mmのポリスチレン粒子が円周方向に等間隔に捕捉された.振動板反射板間の音圧分布及び粒子の捕捉位置は実験値と計算値で良く一致した.PZT素子の分割電極の駆動条件を周方向に変化させることにより,捕捉粒子を周回方向に非接触搬送させることが出来た. |
(英) |
Noncontact ultrasonic particle manipulation with a circular trajectory is discussed. The authors have been investigating the noncontact ultrasonic transportation technique of small objects over long distances using a bending vibration plate and reflector. In the technique, the lattice ultrasound standing-wave filed could be generated between the vibrating plate and a reflector, and small particles could be trapped and manipulated with a straight motion. In this paper, the noncontact transportation of small particles with a circular trajectory was investigated. A 0.5-mm-thick aluminum circular plate with a diameter of 30 mm was employed as a vibrating plate and a 0.5-mm-thick piezoelectric ring was attached to the vibrating plate by epoxy. Being based on the calculated result by a finite element analysis (FEA), the electrodes of piezoelectric ring were divided to 24 pieces to generate a flexural vibration mode with one nodal circle and four nodal lines at the resonance frequency of 47.8 kHz. A circular plate with the same dimension as the vibrating plate was installed parallel to the vibrator with a distance of approximately 5 mm as a reflector to generate an acoustic standing wave in air between them. The acoustic field between the vibrating plate and reflector was calculated via the FEA, and the distribution of the acoustic radiation force acting to a small rigid particle was calculated to predict the position of the trapped particle. By using a prototype of the vibrating plate, polystyrene particles with the diameter of several millimeters could be trapped at the horizontal nodal line of the standing wave with a regular interval. The sound pressure distribution between the vibrating plate and reflector was measured by a fiber optic probe, and the experimental and computed results showed good agreements. By shifting the driving condition of the divided electrodes along the circumferential direction, the nodal lines of the vibrating plate was rotated, and the trapped particle in air could be manipulated with a circular trajectory. |
キーワード |
(和) |
非接触搬送 / 超音波 / たわみ振動 / 有限要素解析 / 音響放射力 / / / |
(英) |
Noncontact transportation / Ultrasound / Frexural vibration / FEA / Acoustic radiation force / / / |
文献情報 |
信学技報, vol. 109, no. 347, US2009-80, pp. 1-6, 2009年12月. |
資料番号 |
US2009-80 |
発行日 |
2009-12-11 (US) |
ISSN |
Print edition: ISSN 0913-5685 Online edition: ISSN 2432-6380 |
著作権に ついて |
技術研究報告に掲載された論文の著作権は電子情報通信学会に帰属します.(許諾番号:10GA0019/12GB0052/13GB0056/17GB0034/18GB0034) |
PDFダウンロード |
US2009-80 |