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Updated: Aug 29, 2026

Optical Trap Loading of Dielectric Microparticles In Air
Published on: February 5, 2017
Periodic oscillation of a colloidal disk near a wall in an optical trap
Zhengdong Cheng1, Thomas G Mason, P M Chaikin
1Corporate Strategic Research, ExxonMobil Research and Engineering Company, Route 22 East, Annandale, New Jersey 08801, USA. zcheng@deas.harvard.edu
Abstract:
Colloidal disks can be stably trapped using optical tweezers. However, when the tweezers press the disk against an opposing wall, we observe an instability leading to periodic motion which we model using coupled nonlinear equations. The resulting "switchback" oscillation involves combined orientational and translational motion of the disk. This observation reveals a new degree of freedom in colloidal architectures, that is, the ability to drive translational motion from a static light field energy source.
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