|
Haake, A., Dual, J.
Micro-manipulation of small particles by node position
control of an ultrasonic standing wave
Ultrasonics, Volume 40, Issues 1-8, May 2002, Pages 317-322
Abstract
For the controlled positioning of small particles with ultrasound a standing
wave in a fluid is used. The standing wave is implemented in a resonator, that
consists of a fluid filled tube and two piezoelectric transducers on each end.
A one-dimensional model of a piezo-device including the fluid-loading on one
side and a backside support is introduced. This model allows the calculation of
the transmitted wave as a function of the applied electric voltage and the
incident wave. In addition, when an electrical impedance is connected to the
piezo-device, the reflection coefficient can be varied in amplitude and phase,
so that the parameters of the reflected wave can be controlled completely.
The resonator itself, consisting of a piezo-device on each end and the fluid
between, is included in the model. Several methods to shift the nodes of the
standing wave in the resonator are investigated and the ability to position
particles is discussed.
01/03/03 | compiled by
Stephan Kaufmann | ZfM
| ETH
|