Low-temperature laser-stimulated controllable generation of micro-bubbles in a water suspension of absorptive colloid particles

Abstract

A method is described for the generation of micrometer-sized vapor-gas bubbles in a water suspension containing absorptive pigment nanoparticles. The diluted suspension (mean interparticle distance 20 μm) absorbs the continuous laser radiation (wavelength 808 nm), and each particle in the best illuminated volume (~10 × 10 × 200 μm) serves as a bubble-nucleation center. The suspension heating is inessential (several degrees above the room temperature) and the bubbles are formed mainly of the air gases dissolved in water. The bubbles can stably exist within or near the illuminated area where their location is governed by the competition between thermal and optical forces and can be controlled via the laser beam parameters. The method enables controllable creation, support, prescribed transportation, and destruction of the bubbles. This can be useful in applications aimed at precise sorting, transportation, and delivery of species in nano- and micro-engineering as well as for biomedical studies.

Single-Nanoparticle Thermometry with a Nanopipette

“…Even though these experiments were carried out in degassed solutions, we cannot confirm if these bubbles are formed by water vapor or air, since the electrolyte solution is exposed to the ambient environment during imaging. Very likely, however, formation of the bubbles occurs at temperatures that are significantly below the water boiling point since the observed temperature increase above the particle deposit does not exceed 10.9 K. However, formation of a micro- or nanobubble can occur even at relatively low temperatures, and the presence of particles (as nuclei for bubble growth) facilitates its stability. , As the dynamics and origin of nucleation of nanobubbles around nanoparticles are of ardent interest both fundamentally and for applications including biology ( e . g ., perforation of tissues and membranes) and photoacoustic imaging (as a trigger of shock waves), SICM thermometry may be an excellent high-resolution tool for studying their origin, evolution of their size, and the local temperature.…”

Polarization - interference mapping of the distributions of the parameters of the Stokes vector of the object field of a biological optically anisotropic layer

“…The ellipticity of polarization was chosen as the main information parameter (without reducing the completeness of the analysis), the value of which is integrally determined by both the birefringence of biochemical crystals and the directions of the optical axes [12][13][14][15][16][17][18][19][20][21][22] fig. 1, fig.…”

Growth of Laser-Induced Microbubbles inside Capillary Tubes Affected by Gathered Light-Absorbing Particles

“…In recent years, a common and convenient method to generate microbubbles is induced by laser heating. Laser-induced microbubbles are generally produced by the thermal effect of radiation with either a continuous-wave (CW) laser [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ] or a pulsed laser [ 26 ]. Materials are used for heating to create microbubbles include absorbing substrates [ 27 , 28 , 29 , 30 , 31 ], absorbing liquids [ 20 , 32 ], and light-absorbing particles (APs) [ 33 , 34 , 35 ].…”