Electrodynamic Trapping of Aerocolloidal Particles: Experimental and Theoretical Trapping Limits

Toward elemental analysis of ambient single particles using electrodynamic balance and laser-induced breakdown spectroscopy

“…However, experiments show that submicron particles charged with a corona-based charger neither stably trap into the focus spot nor oscillate violently, but instead slowly drift away from the trap. The phenomena was also noted by Aardahl et al (1997), who studied the convective forces causing the instability.…”

“…With the maximum amplitude, the achieved charging states should be enough to overcome the trapping limit due to the DC-field. As already mentioned, external forces such as the convective airflow may also disturb the trapping procedure as the particle size gets smaller (e.g., Aardahl et al 1997).…”

Nucleation Behavior of n-Alkane Microdroplets in an Electrodynamic Balance

“…In our previous experiments ,,, on aqueous solutions, the droplets have been charged by induction. However, nonpolar liquids such as alkanes have to be charged externally. , This can be done with the help of a corona discharge between the injector nozzle and the trap. A sharp needle mounted opposite to a grounded plate is kept on a high negative potential ( U = −3 kV).…”

Results of the PROGRA2 Experiment: An Experimental Study in Microgravity of Scattered Polarized Light by Dust Particles with Large Size Parameter

“…Also, levitation techniques in general are feasible for studies on single grains only; it is for instance impossible to achieve a stable levitation for a cloud of irregular particles of varying size and size distribution. Electrodynamic trapping (Aardahl et al 1997, Schnelle 1996 introduces both undesirable polarization and also produces a quasi-stable harmonic motion of the grains about a position where time-averaged forces on particles are zero. The introduction of other forces such as laser-induced radiation pressure and photophoresis disturbs the trapping, and small particles (diameter of a few micrometers) are extremely difficult to trap in practice.…”