Study the effect of acoustic and optical tweezers on a brownian particle

In this study, we investigate the dynamic of a silica spherical microparticle in the presence of optical and acoustic forces. We show that the optical tweezers confine the particle around the focused beam and the acoustic tweezers apply finer force on the particle. We demonstrate the difference in the particle dynamics in the presence and absence of acoustic forces. Applying force on a trapped particle is especially useful to study collective behavior and measure minuscule force between particles and cells. Both tweezers systems have shortcomings and advantages. For example, optical tweezer has a restriction on the heavy particles since they are prone to sink. However, acoustic tweezers can levitate the particles for optical tweezers to trap them. On the other hand, the optical tweezers system can precisely trap and move the trapped particle, while acoustic tweezers are suitable for rough trapping. Combining the two systems can forge a setup that can compensate for each system's limitations.

We show the effect of a 10-megahertz acoustic radiation perpendicular to the focused laser beam with the power of 5mW. We calculated the theoretical trajectory of a particle in the presence of optical and acoustic forces. By applying the acoustic radiation, the particle wiggles in the optical trap. Increasing the acoustic force causes the particle to escape from the optical trap and localization in a pressure nodal plane.