| 1. |
|
|
| 2. |
|
|
| 3. |
- Cruz, F. Javier, 1990-, et al.
(författare)
-
High pressure inertial focusing for separation and concentration of bacteria at high throughput
- 2017
-
Ingår i: 28th Micromechanics and Microsystems Europe Workshop. - : IOP Publishing.
-
Konferensbidrag (refereegranskat)abstract
- Inertial focusing is a phenomenon where particles migrate across streamlines in microchannels and focus at well-defined, size dependent equilibrium points of the cross section. It can be taken into advantage for focusing, separation and concentration of particles at high through-put and high efficiency. As particles decrease in size, smaller channels and higher pressures are needed. Hence, new designs are needed to decrease the pressure drop. In this work a novel design was adapted to focus and separate 1 mu m from 3 mu m spherical polystyrene particles. Also 0.5 mu m spherical polystyrene particles were separated, although in a band instead of a single line. The ability to separate, concentrate and focus bacteria, its simplicity of use and high throughput make this technology a candidate for daily routines in laboratories and hospitals.
|
|
| 4. |
- Cruz, Javier, 1990-, et al.
(författare)
-
Fundamentals of Inertial Focusing in High Aspect Ratio Curved Microfluidics
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Microfluidics exploiting the phenomenon of inertial focusing have attracted much attention in the last decade, as they provide the means to facilitate the detection and analysis of rare particles of interest in complex fluids such as blood and natural water. Although many interesting applications have been demonstrated, the systems remain difficult to engineer. A recently presented line of the technology, inertial focusing in High Aspect Ration Curved (HARC) microfluidics, has the potential to change this and make the benefits of inertial focusing more accessible to the community. In this paper, with experimental evidence and fluid simulations, we provide the two necessary equations to design the systems and successfully focus the desired targets in a single, stable, and high-quality position. Last, the experiments revealed an interesting scaling law of the lift force, which we believe provides a valuable insight into the phenomenon of inertial microfluidics.
|
|
| 5. |
|
|
| 6. |
- Cruz, Javier, 1990-, et al.
(författare)
-
High pressure inertial focusing for separating and concentrating bacteria at high throughput
- 2017
-
Ingår i: Journal of Micromechanics and Microengineering. - : IOP PUBLISHING LTD. - 0960-1317 .- 1361-6439. ; 27:8
-
Tidskriftsartikel (refereegranskat)abstract
- Inertial focusing is a promising microfluidic technology for concentration and separation of particles by size. However, there is a strong correlation of increased pressure with decreased particle size. Theory and experimental results for larger particles were used to scale down the phenomenon and find the conditions that focus 1 mu m particles. High pressure experiments in robust glass chips were used to demonstrate the alignment. We show how the technique works for 1 mu m spherical polystyrene particles and for Escherichia coli, not being harmful for the bacteria at 50 mu l min(-1). The potential to focus bacteria, simplicity of use and high throughput make this technology interesting for healthcare applications, where concentration and purification of a sample may be required as an initial step.
|
|
| 7. |
- Cruz, Javier, 1990-, et al.
(författare)
-
High-resolution Particle Separation by Inertial Focusing in High Aspect Ratio Curved Microfluidics
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The ability to focus, separate and concentrate specific targets in a fluid is essential for the analysis of complex samples such as biological fluids, where a myriad of different particles may be present. Inertial focusing is a very promising technology for such tasks. Recently, inertial focusing in High Aspect Ratio Curved (HARC) microchannels was presented, which simplifies the focusing and concentration of targets by positioning particles close together over a wide range of particle size and flow rate. However, by focusing all particles together, HARC systems lose an essential feature of inertial focusing: the possibility of particle separation by size. Within this work, we report that HARC systems not only do have the capacity to separate particles but can do so with extremely high resolution, which we demonstrate for particles with a size difference down to 80 nm.A model considering the main flow, the secondary flow and a simplified expression for the lift force in HARC microchannels was developed and proven accurate for the prediction of the performance of the systems. The concept was also demonstrated experimentally with three different sub-micron particles (0.79, 0.92 and 1.0 µm in diameter) in silicon-glass microchannels, whose separation distance could be modulated by the radius of the channel.With the capacity to focus sub-micron particles and to separate them with high resolution, inertial focusing in HARC systems are a technology with a strong potential for particle manipulation. We believe that this will facilitate the analysis of complex fluid samples containing bioparticles like bacteria, viruses or eukaryotic organelles.
|
|
| 8. |
- Cruz, Javier, 1990-, et al.
(författare)
-
High-resolution particle separation by inertial focusing in high aspect ratio curved microfluidics
- 2021
-
Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- The ability to focus, separate and concentrate specific targets in a fluid is essential for the analysis of complex samples such as biological fluids, where a myriad of different particles may be present. Inertial focusing is a very promising technology for such tasks, and specially a recently presented variant, inertial focusing in High Aspect Ratio Curved systems (HARC systems), where the systems are easily engineered and focus the targets together in a stable position over a wide range of particle sizes and flow rates. However, although convenient for laser interrogation and concentration, by focusing all particles together, HARC systems lose an essential feature of inertial focusing: the possibility of particle separation by size. Within this work, we report that HARC systems not only do have the capacity to separate particles but can do so with extremely high resolution, which we demonstrate for particles with a size difference down to 80 nm. In addition to the concept for particle separation, a model considering the main flow, the secondary flow and a simplified expression for the lift force in HARC microchannels was developed and proven accurate for the prediction of the performance of the systems. The concept was also demonstrated experimentally with three different sub-micron particles (0.79, 0.92 and 1.0 mu m in diameter) in silicon-glass microchannels, where the resolution in the separation could be modulated by the radius of the channel. With the capacity to focus sub-micron particles and to separate them with high resolution, we believe that inertial focusing in HARC systems is a technology with the potential to facilitate the analysis of complex fluid samples containing bioparticles like bacteria, viruses or eukaryotic organelles.
|
|
| 9. |
- Cruz, Javier, 1990-, et al.
(författare)
-
Inertial focusing of microparticles and its limitations
- 2016
-
Ingår i: 27Th Micromechanics And Microsystems Europe Workshop (Mme 2016). - : IOP Publishing.
-
Konferensbidrag (refereegranskat)abstract
- Microfluidic devices are useful tools for healthcare, biological and chemical analysis and materials synthesis amongst fields that can benefit from the unique physics of these systems. In this paper we studied inertial focusing as a tool for hydrodynamic sorting of particles by size. Theory and experimental results are provided as a background for a discussion on how to extend the technology to submicron particles. Different geometries and dimensions of microchannels were designed and simulation data was compared to the experimental results.
|
|
| 10. |
- Cruz, Javier, 1990-, et al.
(författare)
-
Inertial focusing with sub-micron resolution for separation of bacteria
- 2019
-
Ingår i: Lab on a Chip. - : ROYAL SOC CHEMISTRY. - 1473-0197 .- 1473-0189. ; 19:7, s. 1257-1266
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we study inertial focusing in curved channels and demonstrate the alignment of particles with diameters between 0.5 and 2.0 m, a range of biological relevance since it comprises a multitude of bacteria and organelles of eukaryotic cells. The devices offer very sensitive control over the equilibrium positions and allow two modes of operation. In the first, particles having a large variation in size are focused and concentrated together. In the second, the distribution spreads in a range of sizes achieving separation with sub-micron resolution. These systems were validated with three bacteria species (Escherichia coli, Salmonella typhimurium and Klebsiella pneumoniae) showing good alignment while maintaining the viability in all cases. The experiments also revealed that the particles follow a helicoidal trajectory to reach the equilibrium positions, similar to the fluid streamlines simulated in COMSOL, implying that these positions occupy different heights in the cross section. When the equilibrium positions move to the inner wall as the flow rate increases, they are at a similar distance from the centre than in straight channels (approximate to 0.6R), but when the equilibrium positions move to the outer wall as the flow rate increases, they are closer to the centre and the particles pass close to the inner wall to elevate their position before reaching them. These observations were used along with COMSOL simulations to explain the mechanism behind the local force balance and the migration of particles, which we believe contributes to further understanding of the phenomenon. Hopefully, this will make designing more intuitive and reduce the high pressure demands, enabling manipulation of particles much smaller than a micrometer.
|
|
