Particle Migration by Optical Scattering Force in Microfluidic System With Light-Absorbing Liquid

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Masahiro Motosuke ◽  
Jun Shimakawa ◽  
Dai Akutsu ◽  
Shinji Honami
Keyword(s):  
Laser Beam ◽  
Light Absorption ◽  
Laser Power ◽  
Microfluidic System ◽  
Particle Migration ◽  
Optical Scattering ◽  
Optical Force ◽  
Control Technique ◽  
Temperature Sensitive ◽  
Scattering Force

Optical force offers a promise of being applied as a noninvasive manipulation tool for microscopic objects without physical contact. Particle control in a microfluidic system is achieved by optics showing advantages over electric or the other methods. With optics, the fluid need not to be contamination free and there is no need for electrode fabrication. Particles can experience different forces depending on the optical configuration. The scattering force is predominant under parallel or gently focused irradiation, while the gradient force is predominant in tightly focused irradiation. This paper reports the experimental and theoretical investigations of the potential of optical scattering force for particle control technique in a microfluidic system with a light-absorbing liquid. The light-absorption of the incident laser beam in the liquid causes a temperature rise and induces the corresponding property changes of liquid and particles. The experiments were presented for particle migration using the scattering force exerted by a compact diode laser with a wavelength of 635 nm. The absorption of the light in the liquid was controlled by the concentration of dye substance added in a buffer solution. The velocities of polystyrene particles with a diameter of 1.9 μm and the temperature distributions of the liquid under laser irradiation were measured by tracking their movement and by temperature-sensitive fluorophore, respectively. When there is no light absorption in the liquid, the migration velocity of particles under the laser beam is linearly increased with the increase of the laser power, in agreement with the calculations based on ray optics theory. In the case of light-absorbing liquid, the migration speed of particles experiencing the optical force indicates a nonlinear increase as the laser power increases. This enhancement mainly attributes to the temperature-sensitive change of liquid viscosity resulting in a reduction of viscous drag for migrating particles. An appropriate arrangement of light absorption leads to an enhancement in the photophoretic velocity of particles, and eventual performance promotion of particle separation and/or sorting using the optical force.

Particle Migration by Optical Scattering Force in Microfluidic System With Light-Absorbing Liquid

2009 ◽  
Author(s):  
Masahiro Motosuke ◽  
Jun Shimakawa ◽  
Shinji Honami
Keyword(s):  
Particle Velocity ◽  
Laser Power ◽  
Microfluidic System ◽  
Optical Scattering ◽  
Optical Force ◽  
Physical Contact ◽  
Control Technique ◽  
Viscous Drag ◽  
Fluid Temperature ◽  
Scattering Force

The optical force offers the promise of being applied as noninvasive manipulation tool for microscopic objects without physical contact. The optical scattering force is predominant in the light field with parallel or gently focused beam, while the gradient force in the tightly focused one. The optical approach using the scattering force for the microfluidic system has advantages over the electric or the other methods of particle control, such as no physical contact or no need for electrode fabrication. This paper reports experimental and theoretical investigations of the potential of optical scattering force for particle control technique in a microfluidic system with light-absorbing liquid. Light-absorption of liquid induces the change of liquid properties mainly in the viscosity, which means the decrease of viscous drag for suspended particles. In the experimental system, the light source to exert the optical force was a compact diode laser with the wavelength of 635 nm. The absorption of the beam was controlled by the concentration of dye substance in a buffer solution. Polystyrene particles with the diameter of 1.9 μm were suspended in the liquid flowing in the microchannel. The particle velocity field and fluid temperature distribution were measured by the image processing with the individual particle tracking and by the temperature-sensitive fluorescent dye dissolved in the fluid, respectively. When there is no absorption of the light in the liquid, the particle velocity is linearly increased with the increase of the laser power. The calculated optical force based on the ray optics agrees with this tendency. In the case of the light-absorbing liquid, the migration speed of the particle indicates the nonlinear increase as the laser power increases. This nonlinearity is attributed to temperature dependence of the viscosity of the liquid.

scholarly journals Enhancement of optical force acting on vesicles via the binding of gold nanoparticles

2019 ◽  
Vol 6 (5) ◽  
pp. 190293 ◽  
Author(s):  
Yumeki Tani ◽  
Takashi Kaneta
Keyword(s):  
Gold Nanoparticles ◽  
Light Scattering ◽  
Laser Beam ◽  
Binding Constant ◽  
Electrostatic Interactions ◽  
Propagation Direction ◽  
Optical Force ◽  
Surface Charges ◽  
Scattering Force ◽  
The Relationship

Here we found that gold nanoparticles (AuNPs) enhance the optical force acting on vesicles prepared from phospholipids via hydrophobic and electrostatic interactions. A laser beam was introduced into a cuvette filled with a suspension of vesicles and it accelerated them in its propagation direction via a scattering force. The addition of the AuNPs exponentially increased the velocity of the vesicles as their concentration increased, but polystyrene particles had no significant impact on velocity in the presence of AuNPs. To elucidate the mechanism of the increased velocity, the surface charges in the vesicles and the AuNPs were controlled; the surface charges of the vesicles were varied via the use of anionic, cationic and neutral phospholipids, whereas AuNPs with positive and negative charges were synthesized by coating with citrate ion and 4-dimethylaminopyridine, respectively. All vesicles increased the velocity at different degrees depending on the surface charge. The vesicles were accelerated more efficiently when their charges were opposite those of the AuNPs. These results suggested that hydrophobic and electrostatic interactions between the vesicles and the AuNPs enhanced the optical force. By accounting for the binding constant between the vesicles and the AuNPs, we proposed a model for the relationship between the concentration of the AuNPs and the velocity of the vesicles. Consequently, the increased velocity of the vesicles was attributed to the light scattering that was enhanced when AuNPs were adsorbed onto the vesicles.

scholarly journals Laser Superficial Fusion of Gold Nanoparticles with PEEK Polymer for Cardiovascular Application

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 971
Author(s):  
Oktawian Bialas ◽  
Mateusz Lis ◽  
Anna Woźniak ◽  
Marcin Adamiak
Keyword(s):  
Particle Size ◽  
Laser Beam ◽  
Gold Particle ◽  
Laser Power ◽  
Biomedical Application ◽  
Parameters Optimization ◽  
Size Reduction ◽  
Particle Size Reduction ◽  
Nano Gold ◽  
Gold Particle Size

This paper analyses the possibility of obtaining surface-infused nano gold particles with the polyether ether ketone (PEEK) using picosecond laser treatment. To fuse particles into polymer, the raw surface of PEEK was sputtered with 99.99% Au and micromachined by an A-355 laser device for gold particle size reduction. Biomimetic pattern and parameters optimization were key properties of the design for biomedical application. The structures were investigated by employing surface topography in the presence of micron and sub-micron features. The energy of the laser beam stating the presence of polymer bond thermalisation with remelting due to high temperature was also taken into the account. The process was suited to avoid intensive surface modification that could compromise the mechanical properties of fragile cardiovascular devices. The initial material analysis was conducted by power–depth dependence using confocal microscopy. The evaluation of gold particle size reduction was performed with scanning electron microscopy (SEM), secondary electron (SE) and quadrant backscatter electron detector (QBSD) and energy dispersive spectroscopy (EDS) analysis. The visibility of the constituted coating was checked by a commercial grade X-ray that is commonly used in hospitals. Attempts to reduce deposited gold coating to the size of Au nanoparticles (Au NPs) and to fuse them into the groove using a laser beam have been successfully completed. The relationship between the laser power and the characteristics of the particles remaining in the laser irradiation area has been established. A significant increase in quantity was achieved using laser power with a minimum power of 15 mW. The obtained results allowed for the continuation of the pilot study for augmented research and material properties analysis.

scholarly journals Laser beam calibration for wood surface colour treatment

2021 ◽  
Author(s):  
M. Jurek ◽  
R. Wagnerová
Keyword(s):  
Laser Beam ◽  
Power Control ◽  
Wood Surface ◽  
Laser Power ◽  
Production Quality ◽  
Chemical Processes ◽  
Continuous Control ◽  
Calibration System ◽  
Laser Engraving ◽  
Wood Surfaces

AbstractLaser engraving of photographs on wood surfaces is a challenging task. To optimize the outcome and production quality it is necessary to control every aspect of the laser engraving process. Most of the production machines and technologies overall are mainly focused on laser power control. However, with other systems and deeper knowledge of the wood characteristics it is possible to achieve even better quality. This paper deals with enlarging the number of achievable shades of burned wood and its optimization. A calibration system was developed to control colour shades of engraved wood with a combination of laser power and optic focus. With this approach it is possible to widen achievable palette of engraved shades by continuous control of chemical processes of laser and wood interaction. The production is divided into wood burning and wood carbonization by variation of laser beam focus.

scholarly journals Optical nanomanipulation on solid substrates via optothermally-gated photon nudging

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jingang Li ◽  
Yaoran Liu ◽  
Linhan Lin ◽  
Mingsong Wang ◽  
Taizhi Jiang ◽  
...  
Keyword(s):  
Colloidal Particles ◽  
Solid Substrate ◽  
Optical Scattering ◽  
Functional Nanostructures ◽  
Non Invasive ◽  
Solid Substrates ◽  
All Optical ◽  
Scattering Force ◽  
Reconfigurable Assembly

AbstractConstructing colloidal particles into functional nanostructures, materials, and devices is a promising yet challenging direction. Many optical techniques have been developed to trap, manipulate, assemble, and print colloidal particles from aqueous solutions into desired configurations on solid substrates. However, these techniques operated in liquid environments generally suffer from pattern collapses, Brownian motion, and challenges that come with reconfigurable assembly. Here, we develop an all-optical technique, termed optothermally-gated photon nudging (OPN), for the versatile manipulation and dynamic patterning of a variety of colloidal particles on a solid substrate at nanoscale accuracy. OPN takes advantage of a thin surfactant layer to optothermally modulate the particle-substrate interaction, which enables the manipulation of colloidal particles on solid substrates with optical scattering force. Along with in situ optical spectroscopy, our non-invasive and contactless nanomanipulation technique will find various applications in nanofabrication, nanophotonics, nanoelectronics, and colloidal sciences.

scholarly journals Plasmonic linear nanomotor using lateral optical forces

2020 ◽  
Vol 6 (45) ◽  
pp. eabc3726
Author(s):  
Yoshito Y. Tanaka ◽  
Pablo Albella ◽  
Mohsen Rahmani ◽  
Vincenzo Giannini ◽  
Stefan A. Maier ◽  
...  
Keyword(s):  
Laser Beam ◽  
Incident Light ◽  
Lateral Force ◽  
Diffraction Limit ◽  
Propagation Direction ◽  
Optical Force ◽  
Optical Forces ◽  
Incident Laser ◽  
New Class ◽  
Force Direction

Optical force is a powerful tool to actuate micromachines. Conventional approaches often require focusing and steering an incident laser beam, resulting in a bottleneck for the integration of the optically actuated machines. Here, we propose a linear nanomotor based on a plasmonic particle that generates, even when illuminated with a plane wave, a lateral optical force due to its directional side scattering. This force direction is determined by the orientation of the nanoparticle rather than a field gradient or propagation direction of the incident light. We demonstrate the arrangements of the particles allow controlling the lateral force distributions with the resolution beyond the diffraction limit, which can produce movements, as designed, of microobjects in which they are embedded without shaping and steering the laser beam. Our nanomotor to engineer the experienced force can open the door to a new class of micro/nanomechanical devices that can be entirely operated by light.

scholarly journals Temperature Calibration Measurements based on Laser-Induced Phosphorescence Technique for Combustion Applications

2015 ◽  
Vol 10 (1) ◽  
Keyword(s):  
Laser Radiation ◽  
Laser Beam ◽  
Intensity Ratio ◽  
Laser Power ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Temperature Calibration ◽  
Phosphor Powder ◽  
Calibration Methods

Phosphor powder and phosphor-binder mixtures are successfully employed for temperature calibration measurements by using laser-induced phosphorescence (LIP) technique with an emphasis on higher precisions and accuracies than other non-intrusive methods. The phosphorescence intensities are used to perform these calibrations in three different strategies. The influence of laser power regular changes on particles heating and the calibration analyses is also carried out. A pulsed laser at 355 nm was used for exciting specimens of the phosphor powder as well as the phosphor-binder mixtures. The laser beam was directed onto the specimens and varied in three laser power levels (LPLs). The samples were kept in an oven with temperatures ranging from room temperature up to 1800 °C. The three strategies which are expressed in terms of non-dimensional intensity versus wavelength (NDI-W), normalised intensity (NI) and intensity ratio (IR) were used for the calibration assessments. A modified IR was compared with two different IRs. A precision of around ± (0.50-1.41)% was attained for different calibration methods. This research confirmed that these calibrations are possible using three different strategies, given high precisions and accuracies. The laser power alternations influenced the NI and do affect neither the NDI-W nor the IR curves. The laser radiation does not play any role for heating the particles of the studied powder.

scholarly journals Effect of Laser Parameters on Sequential Laser Beam Micromachining and Micro Electro-Discharge Machining

2021 ◽  
Author(s):  
Mir Akmam Noor Rashid ◽  
Tanveer Saleh ◽  
Wazed Ibne Noor ◽  
Mohamed Sultan Mohamed Ali
Keyword(s):  
Laser Beam ◽  
Laser Power ◽  
Short Circuit ◽  
Scanning Speed ◽  
Hole Drilling ◽  
Machining Time ◽  
Research Attention ◽  
Pilot Hole ◽  
Electro Discharge Machining ◽  
Input Parameters

Abstract Laser beam micromachining (LBMM) and micro electro-discharge machining (µEDM) based sequential micromachining technique, LBMM-µEDM has drawn significant research attention to utilizing the advantages of both methods, i.e. LBMM and µEDM. In this process, a pilot hole is machined by the LBMM and subsequently finishing operation of the hole is carried out by the µEDM. This paper presents an experimental investigation on the stainless steel (type SS304) to observe the effects of laser input parameters (namely laser power, scanning speed, and pulse frequency) on the performance of the finishing technique that is the µEDM in this case. The scope of the work is limited to 1-D machining, i.e. drilling micro holes. It was found that laser input parameters mainly scanning speed and power influenced the output performance of µEDM significantly. Our study suggests that if an increased scanning speed at a lower laser power is used for the pilot hole drilling by the LBMM process, it could result in significantly slower µEDM machining time. On the contrary, if the higher laser power is used with even the highest scanning speed for the pilot hole drilling, then µEDM processing time was faster than the previous case. Similarly, µEDM time was also quicker for LBMMed pilot holes machined at low laser power and slow scanning speed. Our study confirms that LBMM-µEDM based sequential machining technique reduces the machining time, tool wear and instability (in terms of short circuit count) by a margin of 2.5 x, 9 x and 40 x respectively in contrast to the pure µEDM process without compromising the quality of the holes.

Analysis of Roughness and Heat Affected Zone of Steel Plates Obtained by Laser Cutting

2014 ◽  
Vol 974 ◽  
pp. 169-173 ◽  
Author(s):  
Imed Miraoui ◽  
Mohamed Boujelbene ◽  
Emin Bayraktar
Keyword(s):  
Surface Roughness ◽  
Laser Beam ◽  
Heat Affected Zone ◽  
Laser Power ◽  
Laser Cutting ◽  
Major Effect ◽  
Steel Plates ◽  
Beam Diameter ◽  
Laser Beam Diameter ◽  
Cut Surface

In the present study, high-power CO2 laser cutting of steel plates has been investigated and the effect of the input laser cutting parameters on the cut surface quality is analyzed. The average roughness of the cut surface of the specimens, produced by different laser beam diameter and laser power, were measured by using roughness tester. The scanning electron microscopy SEM is used to record possible metallurgical alterations on the cut edge. The aim of this work is to investigate the effect of laser beam diameter and laser power on the cut surface roughness and on the heat affected zone width HAZ of steel plates obtained by CO2 laser cutting. An overall optimization was applied to find out the optimal cutting setting that would improve the cut surface quality. It was found that laser beam diameter has a negligible effect on surface roughness but laser power had major effect on roughness. The cut surface roughness decreases as laser power increases. Improved surface roughness can be obtained at higher laser power. Also, laser beam diameter and laser power had major effect on HAZ width. It increases as laser power increases.

Sign in / Sign up

Export Citation Format

Share Document