scholarly journals Sequential storage and release of microdroplets

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zenon Toprakcioglu ◽  
Tuomas P. J. Knowles
Keyword(s):  
Analytical Chemistry ◽  
Continuous Phase ◽  
Chemical Processes ◽  
Computational Simulations ◽  
Droplet Deformation ◽  
Critical Rate ◽  
Storage And Retrieval ◽  
Key Features ◽  
On Chip ◽  
Shed Light

AbstractDroplet microfluidic methods have opened up the possibility of studying a plethora of phenomena ranging from biological to physical or chemical processes at ultra low volumes and high throughput. A key component of such approaches is the ability to trap droplets for observation, and many device architectures for achieving this objective have been developed. A challenge with such approaches is, however, recovering the droplets following their confinement for applications involving further analysis. Here, we present a device capable of generating, confining and releasing microdroplets in a sequential manner. Through a combination of experimental and computational simulations, we shed light on the key features required for successful droplet storage and retrieval. Moreover, we explore the effect of the flow rate of the continuous phase on droplet release, determining that a critical rate is needed to ensure complete droplet deformation through constrictions holding the droplets in place prior to release. Finally, we find that once released, droplets can be retrieved and collected off chip. The ability to generate, store and sequentially release droplets renders such a device particularly promising for future applications where reactions may not only be monitored on-chip, but droplets can also be retrieved for further analysis, facilitating new exploratory avenues in the fields of analytical chemistry and biology.

scholarly journals Sequential Storage and Release of Microdroplets for On and Off-chip Analysis

2021 ◽  
Author(s):  
Zenon Toprakcioglu ◽  
Tuomas Knowles
Keyword(s):  
Continuous Phase ◽  
Chemical Processes ◽  
Computational Simulations ◽  
Droplet Deformation ◽  
Critical Rate ◽  
Storage And Retrieval ◽  
Key Features ◽  
On Chip ◽  
Shed Light ◽  
Chip Analysis

Droplet microfluidic methods have opened up the possibility of studying a plethora of phenomena ranging from biological to physical or chemical processes at ultra-low volumes and high throughput. A key component of such approaches is the ability to trap droplets for observation, and many device architectures for achieving this objective have been developed. A challenge with such approaches is, however, recovering the droplets following their confinement for applications involving further analysis. Here, we present a device capable of generating, confining and releasing microdroplets in a sequential manner. Through a combination of experimental and computational simulations, we shed light on the key features required for successful droplet storage and retrieval. Moreover, we explore the effect of the ow rate of the continuous phase on droplet release, determining that a critical rate is needed to ensure complete droplet deformation through constrictions holding the droplets in place prior to release. Finally, we find that once released, droplets can be retrieved and collected off chip. The ability to generate, store and sequentially release droplets renders such a device particularly promising for future applications where reactions may not only be monitored on-chip, but droplets can be retrieved for further analysis, facilitating new exploratory avenues in the fields of analytical chemistry and biology.

Design of Router Supporting Multiply Routing Algorithm for NoC

2014 ◽  
Vol 981 ◽  
pp. 431-434
Author(s):  
Zhan Peng Jiang ◽  
Rui Xu ◽  
Chang Chun Dong ◽  
Lin Hai Cui
Keyword(s):  
Complex System ◽  
High Performance ◽  
Routing Algorithm ◽  
Network On Chip ◽  
System On Chip ◽  
Low Latency ◽  
Deterministic Routing ◽  
Key Features ◽  
Design Challenge ◽  
On Chip

Network on Chip(NoC)，a new proposed solution to solve global communication problem in complex System on Chip (SoC) design，has absorbed more and more researchers to do research in this area. Due to some distinct characteristics, NoC is different from both traditional off-chip network and traditional on-chip bus，and is facing with the huge design challenge. NoC router design is one of the most important issues in NoC system. The paper present a high-performance, low-latency two-stage pipelined router architecture suitable for NoC designs and providing a solution to irregular 2Dmesh topology for NoC. The key features of the proposed Mix Router are its suitability for 2Dmesh NoC topology and its capability of suorting both full-adaptive routing and deterministic routing algorithm.

scholarly journals Deformation characteristics of a single droplet driven by a piezoelectric nozzle of the drop-on-demand inkjet system

2019 ◽  
Vol 869 ◽  
pp. 634-645 ◽  
Author(s):  
Shangkun Wang ◽  
Yonghong Zhong ◽  
Haisheng Fang
Keyword(s):  
Surface Tension ◽  
Pressure Wave ◽  
Deformation Process ◽  
Deformation Characteristics ◽  
Single Droplet ◽  
Computational Simulations ◽  
Droplet Deformation ◽  
On Demand ◽  
Drop On Demand ◽  
Maximum Value

In the drop-on-demand (DOD) inkjet system, deformation process and the direct relations between the droplet motions and the liquid properties have been seldom investigated, although they are very critical for the printing accuracy. In this study, experiments and computational simulations regarding deformation of a single droplet driven by a piezoelectric nozzle have been conducted to address the deformation characteristics of droplets. It is found that the droplet deformation is influenced by the pressure wave propagation in the ink channel related to the driven parameters and reflected in the subsequent droplet motions. The deformation extent oscillates with a certain period of $T$ and a decreasing amplitude as the droplet moves downwards. The deformation extent is found strongly dependent on the capillary number ($Ca$), first ascending and then descending as the number increases. The maximum value of the deformation extent is surprisingly found to be within range of 0.068–0.082 of the $Ca$ number regardless of other factors. Furthermore, the Rayleigh’s linear relation of the oscillation frequency of the droplet to the parameter, $\sqrt{\unicode[STIX]{x1D70E}/\unicode[STIX]{x1D70C}r^{3}}$ (where $\unicode[STIX]{x1D70E}$ is the surface tension coefficient, $\unicode[STIX]{x1D70C}$ is the density and $r$ is the droplet’s radius), is updated with a smaller slope shown both by experiment and simulation.

Advanced sub 0.13µm Cu Devices – Failure Analysis and Circuit Edit With Improved FIB Chemical Processes and Beam Characteristics

2002 ◽  
Author(s):  
J. David Casey ◽  
Thomas J. Gannon ◽  
Alex Krechmer ◽  
David Monforte ◽  
Nicholas Antoniou ◽  
...  
Keyword(s):  
Failure Analysis ◽  
High Speed ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Chemical Processes ◽  
Design Verification ◽  
End Point Detection ◽  
On Chip ◽  
Point Detection ◽  
Low K

Abstract Advances in FIB (focused ion beam) chemical processes and in the Ga (gallium) beam profile are discussed; these advances are necessary for the successful failure analysis, circuit edit and design verification of advanced, sub-0.13µm Cu devices. Included in this article are: a novel FIB method (CopperRx) for smoothly milling thick, large grained Cu lines; H2O and O2 processes for cleanly cutting thin, smaller grained Cu lines, thereby forming electrically open interconnects; a XeF2 GAE (gas assisted etching) process for etching low k, CVD dielectrics such as F and C doped SiO2; H2O and XeF2 GAE processes for etching low k, spin-on, organic dielectrics such as SiLK; a recently developed recipe for the deposition of SiO2 based material with intermediate resistivity (106 µohm·cm) which is useful in the design verification of frequency sensitive, high speed analog and SOC (system on chip) circuits; an improved, more Gaussian Ga beam with less current density in the beam tails (VisION column) which provides higher resolution, real time images needed for end-point detection on sub 0.13µm features during milling.

scholarly journals Eye development in the four-eyed fish Anableps anableps : cranial and retinal adaptations to simultaneous aerial and aquatic vision

2017 ◽  
Vol 284 (1852) ◽  
pp. 20170157 ◽  
Author(s):  
Louise N. Perez ◽  
Jamily Lorena ◽  
Carinne M. Costa ◽  
Maysa S. Araujo ◽  
Gabriela N. Frota-Lima ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
Cell Layer ◽  
Eye Development ◽  
Frontal Bone ◽  
Larval Stages ◽  
Layer Density ◽  
Key Features ◽  
Insight Into ◽  
Shed Light

The unique eyes of the four-eyed fish Anableps anableps have long intrigued biologists. Key features associated with the bulging eye of Anableps include the expanded frontal bone and the duplicated pupils and cornea. Furthermore, the Anableps retina expresses different photoreceptor genes in dorsal and ventral regions, potentially associated with distinct aerial and aquatic stimuli. To gain insight into the developmental basis of the Anableps unique eye, we examined neurocranium and eye ontogeny, as well as photoreceptor gene expression during larval stages. First, we described six larval stages during which duplication of eye structures occurs. Our osteological analysis of neurocranium ontogeny revealed another distinctive Anablepid feature: an ossified interorbital septum partially separating the orbital cavities. Furthermore, we identified the onset of differences in cell proliferation and cell layer density between dorsal and ventral regions of the retina. Finally, we show that differential photoreceptor gene expression in the retina initiates during development, suggesting that it is inherited and not environmentally determined. In sum, our results shed light on the ontogenetic steps leading to the highly derived Anableps eye.

Separation-driven coalescence of droplets: an analytical criterion for the approach to contact

2009 ◽  
Vol 632 ◽  
pp. 97-107 ◽  
Author(s):  
ANN LAI ◽  
NICOLAS BREMOND ◽  
HOWARD A. STONE
Keyword(s):  
Viscosity Ratio ◽  
Continuous Phase ◽  
Separation Distance ◽  
Dimensional Model ◽  
Droplet Deformation ◽  
Dimensional Parameter ◽  
Domain Perturbation ◽  
Microfluidic Flow ◽  
Analytical Criterion ◽  
Good Agreement

Recent microfluidic experiments by Bremond, Thiam & Bibette (Phys. Rev. Lett., vol. 100, 2008, paper no. 024501), along with simulations by Yoon et al. (Phys. Fluid, vol. 19, 2007, paper no. 102102) and near-contact experiments and simulations by Manica et al. (Langmuir, vol. 24, 2008, pp. 1381–1390), have demonstrated that two droplets can coalesce as they are separating rather than upon their collision. We analyse the experimental microfluidic flow configuration for the approach to contact with a two-dimensional model: we apply a lubrication analysis followed by the method of domain perturbation to determine the droplet deformation as a function of time. We find the approximate shape for the deformed droplet at the time of contact. In particular, for droplets of radius R, moving apart according to h0(t) = h0(0) + αt2, where 2h0(t) is the separation distance, we define a non-dimensional parameter A=4CμR2α1/2/πγ[h0(0)]3/2, where μ is the viscosity of the continuous phase; γ is the interfacial tension; and C depends on the viscosity ratio between the droplets and the continuous phase. Our model suggests that there exists a critical value Acrit = 16/33/2 ≈ 3.0792, below which separation is unlikely to facilitate the coalescence of the droplets. The predictions are in good agreement with available experimental data.

scholarly journals Rights transfers in Madagascar biodiversity policies: achievements and significance

2004 ◽  
Vol 9 (6) ◽  
pp. 825-847 ◽  
Author(s):  
MARTINE ANTONA ◽  
ESTELLE MOTTE BIÉNABE ◽  
JEAN-MICHEL SALLES ◽  
GÉRALDINE PÉCHARD ◽  
SIGRID AUBERT ◽  
...  
Keyword(s):  
Natural Resources ◽  
Central Government ◽  
Local Communities ◽  
Natural Resources Management ◽  
Practical Implementation ◽  
Resources Management ◽  
Delegation Of Authority ◽  
Trade Offs ◽  
Key Features ◽  
Shed Light

Decentralization and people's participation have been key features of government environmental policy since the 1990s. In Madagascar, the policy of Secured Local Management of Natural Resources, known as the GELOSE act, has created a framework for the transfer of rights from central government to local communities. This article analyses the practical implementation of this policy by focusing on the nature of the rights transferred and on the nature of the contracts and incentives developed. The Aghion and Tirole model for allocation of formal and real authority in an organization is used to shed light on the contractual definition process and on the trade-offs between giving responsibilities to local communities and losing control over natural resources management. It is shown that a congruence of interests between the parties is crucial for effective delegation of authority to local communities and that this congruence may emerge in relation to the transfer of exclusion rights.

Membrane Integration into PDMS-free Microfluidic Platforms for Organ-on-Chip and Analytical Chemistry Applications

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Stefan Schneider ◽  
Denise Gruner ◽  
Andreas Richter ◽  
Peter Loskill
Keyword(s):  
Analytical Chemistry ◽  
Crucial Role ◽  
Microfluidic Systems ◽  
Microfluidic Platforms ◽  
Research Fields ◽  
On Chip ◽  
Robust Integration

Membranes play a crucial role in many microfluidic systems, enabling versatile applications in highly diverse research fields. However, the tight and robust integration of membranes into microfluidic systems requires complex...

scholarly journals Microfluidic on-chip Production of Alginate Hydrogels Using Double Co-flow Geometry

2021 ◽  
Author(s):  
Amirmohammad Sattari ◽  
Sajad Janfaza ◽  
Mohsen Mashhadi Keshtiban ◽  
Nishat Tasnim ◽  
Pedram Hanafizadeh ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Precursor Solution ◽  
Average Diameter ◽  
Continuous Phase ◽  
Solution Viscosity ◽  
Flow Conditions ◽  
External Gelation ◽  
Flow Geometry ◽  
On Chip ◽  
Spherical Droplets

Abstract Microfluidic on-chip production of microgels employing external gelation has numerous biological and pharmaceutical applications, particularly for the encapsulation of delicate cargos, however, the on-chip production of microgels in microfluidic devices can be challenging due to problems such as clogging caused by accelerated progress in precursor solution viscosity. Here, we introduce a novel microfluidic design incorporating two consecutive co-flow geometries for microfluidic droplet generation. A shielding oil phase is employed to avoid emulsification and gelation stages from occurring simultaneously, thereby preventing clogging. The results revealed that the microfluidic device could generate highly monodispersed spherical droplets (coefficient of variation < 3%) with an average diameter in the range of 60–200 μm. Additionally, it was demonstrated that the device could appropriately create a shelter of the oil phase around the inner aqueous phase regardless of the droplet formation regime and flow conditions. The ability of the proposed microfluidic device in the generation of microgels was validated by producing alginate microgels utilizing an aqueous solution of calcium chloride as the continuous phase.

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