Detaching and moving of adhered particles with a photoacoustic micro-resonator

In this work, a method of causing solid-phase adhered particles to detach and move via photoacoustic resonance was studied. A laser micro-resonator was designed for excitation of the photoacoustic resonance. Both simulation and experimental results showed that a sound field was formed due to transient photoacoustic interactions between the laser and the resonator. A fundamental resonance was found at 18.9 kHz when the laser harmonized with the Eigen-frequency of the resonator. For the 100 μJ/pulse laser energy, the maximum centrifugal acceleration of 3.6 × 105 m/s2 was acquired by the fundamental photoacoustic resonance. The micro-resonator performed competently for the detachment of adhered particles larger than 5 μm. Particle motion could be controlled with an acceleration or constant speed by manipulating the laser frequency and energy. This photoacoustic manipulation of microscopic objects may have applications in separation and fixation of cells, giant molecules, and dusts in lab-on-a-chip systems.In this work, a method of causing solid-phase adhered particles to detach and move via photoacoustic resonance was studied. A laser micro-resonator was designed for excitation of the photoacoustic resonance. Both simulation and experimental results showed that a sound field was formed due to transient photoacoustic interactions between the laser and the resonator. A fundamental resonance was found at 18.9 kHz when the laser harmonized with the Eigen-frequency of the resonator. For the 100 μJ/pulse laser energy, the maximum centrifugal acceleration of 3.6 × 105 m/s2 was acquired by the fundamental photoacoustic resonance. The micro-resonator performed competently for the detachment of adhered particles larger than 5 μm. Particle motion could be controlled with an acceleration or constant speed by manipulating the laser frequency and energy. This photoacoustic manipulation of microscopic objects may have applications in separation and fixation of cells, giant molecules, and dusts in lab-on-a-chip systems.