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

Abstract

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.

Plasmon-driven nanowire actuators for on-chip manipulation

“…12), and the maximum expansion can be estimated as 0.17 nm, which agrees with the experimental result. Besides, the calculated moving speed is 6.5 μm s −1 per milliwatt of the 1064 nm laser power, which is two orders of magnitude larger than the micro/nanoparticle transport speed using optical tweezers and near-field evanescent forces (actuation average power typically exceeds tens of milliwatts) 24,34,35 , suggesting the higher efficiency of our plasmon driven approach.…”

“…Currently, a common manipulation method in air environments is manually using 3D stage-actuated tungsten or silica probes to apply thrust on the nanowire sides 6,7,18,19 , but the nanowires can only be moved laterally with accuracy of ~1 μm. On the other hand, surface acoustic waves (SAWs) induced by the elastic expansion of metal lattices under transient heating of pulsed lasers [20][21][22] , have been used to drive microscale metal objects for surface cleaning, particle detaching, and microplate rotating [23][24][25] , thus providing the possibility of overcoming the strong surface adhesion to manipulate metal nanowires in non-liquid environments.…”

Heat-Mediated Optical Manipulation

“…Shape deformation caused by optothermally induced surface acoustic waves (SAWs) has been exploited for the directional motion of metal nanostructures on solid substrates. 453 For instance, Linghu et al demonstrated the crawling of Au nanowires on a silica fiber (Figure 35a). 168 When a pulsed 1064 nm laser was channeled through the silica fiber, surface plasmon polaritons were excited on the Au nanowire, which generated abundant thermal energy at the front end of the nanowire.…”

“…Shape deformation caused by optothermally induced surface acoustic waves (SAWs) has been exploited for the directional motion of metal nanostructures on solid substrates . For instance, Linghu et al demonstrated the crawling of Au nanowires on a silica fiber (Figure a) .…”

Optical manipulation and assembly of micro/nanoscale objects on solid substrates

“…Shape deformation of objects can also be caused by optothermally induced SAWs, which have been exploited for optical navigation of plasmonic nanoobjects on solid substrates ( Li et al., 2019a ). Recently, Linghu et al.…”