Design of traveling-wave field panel for pharmaceutical powders based on computer simulation of particle trajectories

A fundamental study of charged particle levitation and transport in a traveling-wave field was carried out with a view to design and manufacture a series of flatbed panels with embedded electrode arrangement. Fourier transformation technique has been used to provide boundary conditions for the numerical calculations of particle trajectories. From the analysis, a potential function can be extracted which gives a better approximation compared to the one given by Masuda's early work. The numerical method using finite element and finite difference technique to solve field and trajectories, respectively, has been employed with a well-designed user interface. The user interface for integrating both methods is of universal value on its own. Based on this study, a computer program is under development with three levels of accuracy. The first level with consideration of the first spatial harmonic is presented in this paper, which is sufficient for designing panel electrode arrangements for the confinement and transport of dry powders. For the advanced study of particle trajectories under higher harmonic vectors, levels 2 and 3 (currently under development) may be utilized to serve different user requirement of accuracy. A series of panel electrodes have been designed and manufactured based on the analyses presented in this paper. Using these panels, lactose powder samples were successfully levitated and transported in the desired direction. Experimental observation is in good agreement with the numerical results.