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Measurement and accumulation of electric charge on a single dielectric particle trapped in air



Thomas W. LeBrun, Haesung Park


Normally occurring charges on small particles provide a means to control the motion of the particles. Using a piezoelectric- based resonator to launch microparticles into a trap, we can vary particle-surface interactions to transfer charge to the particle via contact electrification. This allows more detailed studies of contact electrification itself as well generation of higher charge states for precision measurements of force or nonlinear dynamics using electric field modulation. In practice, particles may be repeatedly landed on the substrate and relaunched during loading. This leads to charge transfer so that the net charge on the polystyrene (PS) particle becomes sufficient to allow electrostatic forcing to drive ballistic motion over a range of displacement two orders of magnitude greater than thermal fluctuations. An increase in charge from 1000 to 3000 electrons is demonstrated and the induced motion of the trapped particle is accurately described using simple classical mechanics in phase space.
Proceedings Title
SPIE OptoWest
Conference Dates
February 13-18, 2016
Conference Location
San Francisco, CA


Optical levitation, contact electrification, electrostatic modulation, parametric force analysis, arbitrary force measurement, microparticles, optical tweezers, optical trapping, nonlinear dynamics


LeBrun, T. and Park, H. (2016), Measurement and accumulation of electric charge on a single dielectric particle trapped in air, SPIE OptoWest, San Francisco, CA, [online], (Accessed July 24, 2024)


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Created March 4, 2016, Updated November 10, 2018