Related Experiment Video
Updated: Jul 18, 2026

Optical Trap Loading of Dielectric Microparticles In Air
Published on: February 5, 2017
The escape of a particle from a driven harmonic potential to an attractive surface
Z Tshiprut1, J Klafter, M Urbakh
1School of Chemistry, Tel Aviv University, 69978 Tel Aviv, Israel.
Abstract:
We investigate theoretically the dynamics of a colloidal particle, trapped by optical tweezers, which gradually approaches an attractive surface with a constant velocity until it escapes the trap and jumps to the surface. We find that the height of the energy barrier in such a colloid-surface system follows the scaling DeltaE proportional, variant(z(0)(t)-const)(32) when the trap approaches the surface, z(0)(t) being the trap surface distance. Using this scaling we derive equations for the probability density function of the jump lengths, for the velocity dependence of its mean and most probable values, and for the variance. These can be used to extract the parameters of the particle-surface interaction from experimental data.
Related Concept Videos
Escape Velocity
To calculate the escape velocity, it is assumed that no energy is lost to any frictional forces. In practice, a satellite launched from...
Forced Oscillations
Motion Of A Charged Particle In A Magnetic Field
Energy Diagrams - II
The point in the energy diagram at which the system’s potential energy is the lowest is known as the local minima. The system tends to stay in this position indefinitely unless acted upon by a net force. The slope of the potential energy diagram at the local minima is zero, indicating that zero net force is acting on the system. The slope...
Atomic Nuclei: Nuclear Relaxation Processes
Problem Solving: Energy in Simple Harmonic Motion
Consider the spring in a shock absorber of a car. The spring attached to the wheel executes simple harmonic motion while the car is moving on a bumpy road. The force on the...

