scholarly journals Light-Driven Droplet Manipulation Technologies for Lab-on-a-Chip Applications

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Sung-Yong Park ◽  
Pei-Yu Chiou
Keyword(s):  
High Speed ◽  
Digital Microfluidics ◽  
Lab On A Chip ◽  
High Energy ◽  
High Energy Density ◽  
Massively Parallel ◽  
Physical Mechanisms ◽  
Recent Developments ◽  
Droplet Manipulation ◽  
Light Beams

Droplet-based (digital) microfluidics has been demonstrated in many lab-on-a-chip applications due to its free cross-contamination and no dispersion nature. Droplet manipulation mechanisms are versatile, and each has unique advantages and limitations. Recently, the idea of manipulating droplets with light beams either through optical forces or light-induced physical mechanisms has attracted some interests, since light can achieve 3D addressing, carry high energy density for high speed actuation, and be patterned and dynamically reconfigured to generate a large number of light beams for massively parallel manipulation. This paper reviews recent developments of various optical technologies for droplet manipulation and their applications in lab-on-a-chip.

Thermal Model of a Thin Film Pulsed Pyroelectric Generator

2016 ◽  
Author(s):  
Nicholas R. Jankowski ◽  
Andrew N. Smith ◽  
Brendan M. Hanrahan
Keyword(s):  
Thin Film ◽  
Power Generation ◽  
Energy Conversion ◽  
High Speed ◽  
High Energy ◽  
High Energy Density ◽  
Working Fluid ◽  
Film Material ◽  
Thermodynamic Cycles ◽  
The Impact

Recent high energy density thin film material development has led to an increased interest in pyroelectric energy conversion. Using state-of-the-art lead-zirconate-titanate piezoelectric films capable of withstanding high electric fields we previously demonstrated single cycle energy conversion densities of 4.28 J/cm3. While material improvement is ongoing, an equally challenging task involves developing the thermal and thermodynamic process though which we can harness this thermal-to-electric energy conversion capability. By coupling high speed thermal transients from pulsed heating with rapid charge and discharge cycles, there is potential for achieving high energy conversion efficiency. We briefly present thermodynamic equivalent models for pyroelectric power generation based on the traditional Brayton and Ericsson cycles, where temperature-pressure states in a working fluid are replaced by temperature-field states in a solid pyroelectric material. Net electrical work is then determined by integrating the path taken along the temperature dependent polarization curves for the material. From the thermodynamic cycles we identify the necessary cyclical thermal conditions to realize net power generation, including a figure of merit, rEC, or the electrocaloric ratio, to aid in guiding generator design. Additionally, lumped transient analytical heat transfer models of the pyroelectric system with pulsed thermal input have been developed to evaluate the impact of reservoir temperatures, cycle frequency, and heating power on cycle output. These models are used to compare the two thermodynamic cycles. This comparison shows that as with traditional thermal cycles the Ericsson cycle provides the potential for higher cycle work while the Brayton cycle can produce a higher output power at higher thermal efficiency. Additionally, limitations to implementation of a high-speed Ericsson cycle were identified, primarily tied to conflicts between the available temperature margin and the requirement for isothermal electrical charging and discharging.

Recent developments of Co3O4-based materials as the catalysts for oxygen evolution reaction

2021 ◽  
Author(s):  
Zhenyu Hu ◽  
Liping Hao ◽  
Fan Quan ◽  
Rui Guo
Keyword(s):  
Energy Density ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Fossil Fuels ◽  
High Energy ◽  
High Energy Density ◽  
Environmental Concerns ◽  
Efficient Energy ◽  
Recent Developments

The demand for the development of clean and efficient energy is becoming more and more pressing due to depleting fossil fuels and environmental concerns. Hydrogen is a high energy density...

Ignition Characteristics of a New High-Energy Density Fuel in High-Speed Flows

1997 ◽  
Vol 13 (2) ◽  
pp. 246-249 ◽  
Author(s):  
C. Segal ◽  
M. J. Friedauer ◽  
H. S. Udaykumar ◽  
W. Shyy ◽  
A. P. Marchand
Keyword(s):  
Energy Density ◽  
High Speed ◽  
High Energy ◽  
High Energy Density ◽  
Ignition Characteristics ◽  
High Speed Flows ◽  
High Energy Density Fuel

The Critical Pressure at the Onset of Flame Instability of Syngas/Air/Diluent Outwardly Expanding Flame at Different Initial Temperatures and Pressures

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Ziyu Wang ◽  
Ziwei Bai ◽  
Guangying Yu ◽  
Sai Yelishala ◽  
Hameed Metghalchi
Keyword(s):  
High Speed ◽  
Critical Pressure ◽  
Hydrodynamic Instability ◽  
Experimental Studies ◽  
Initial Pressure ◽  
High Energy ◽  
Oxide Semiconductor ◽  
High Energy Density ◽  
Flame Instability ◽  
Wide Range

Syngas has gained attention recently due to its high energy density and environmentally friendly characteristics. Flame stability plays an important role in flame propagation in energy conversion devices. Experimental studies were performed in a cylindrical chamber to investigate flame instability of syngas/air/diluent mixture. A Z-shape Schlieren system coupled with a high-speed complementary metal–oxide–semiconductor camera was used to record flame pictures up to 40,000 frames per second. In this research, syngas is a mixture of hydrogen and carbon monoxide and diluent is a blend of 14% CO2 and 86% N2 with the same specific heat as the burned gases. Three main flame instabilities namely Rayleigh–Taylor (body force) instability, hydrodynamic instability, and thermal-diffusive instability have been studied. For the onset of flame instability, a power law correlation for the ratio of critical pressure to initial pressure of syngas/air/diluent flames over a wide range of initial temperatures (298–450 K), initial pressures (1.0–2.0 atm), equivalence ratios (0.6–3.0), diluent concentrations (0–10%), and hydrogen percentages (5–25%) in the fuel has been developed.

Joining of Tubular Parts by Electromagnetic Forming; Experimental Investigations

2014 ◽  
Vol 792 ◽  
pp. 115-120 ◽  
Author(s):  
Pál Rácz ◽  
Nándor Göbl ◽  
Daniel Horváth ◽  
Athanasios G. Mamalis
Keyword(s):  
High Speed ◽  
New Technologies ◽  
Dissimilar Materials ◽  
High Energy ◽  
Mechanical Tests ◽  
Electromagnetic Forming ◽  
High Energy Density ◽  
Experimental Investigations ◽  
Forming Process ◽  
High Speed Forming

Electromagnetic forming is a high speed forming process, wherein the forming pressure is created by high energy density electromagnetic pulse. Besides direct shaping there are other application areas as well, so electromagnetic plastic forming is a potential field of creating joints between tube and rod-like components. Connecting components of dissimilar materials is an increasing demand in the manufacturing process of structures in the automotive industry. The application of new technologies, such as electrodynamic, especially electromagnetic forming, is a possible method to satisfy these demands. The article summarizes the most important fundamentals of electromagnetic forming; in particular, tube-rod joints, the main types of such joints; interference-fit and form-fit joints are described. Experiments, which were carried out producing tube-rod joints with electromagnetic forming, are also introduced. A new type of form-fit joints for tube-rod connections has been developed, which can withstand not only tensile loads but also torsion. Experiments and mechanical tests have proved the applicability of this kind of joints.

scholarly journals Meso/macroscopically multifunctional surface interfaces, ridges, and vortex-modified anode/cathode cuticles as force-driven modulation of high-energy density of LIB electric vehicles

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
H. Khalifa ◽  
S. A. El-Safty ◽  
A. Reda ◽  
M. A. Shenashen ◽  
M. M. Selim ◽  
...  
Keyword(s):  
Energy Density ◽  
High Speed ◽  
Large Scale ◽  
Coulombic Efficiency ◽  
Scale Up ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Diverse Range

Abstract Modulation of lithium-ion battery (LIB) anodes/cathodes with three-dimensional (3D) topographical hierarchy ridges, surface interfaces, and vortices promotes the power tendency of LIBs in terms of high-energy density and power density. Large-scale meso-geodesics offer a diverse range of spatial LIB models along the geodetically shaped downward/upward curvature, leading to open-ended movement gate options, and diffusible space orientations. Along with the primary 3D super-scalable hierarchy, the formation of structural features of building block egress/ingress, curvature cargo-like sphere vehicles, irregularly located serrated cuticles with abundant V-undulated rigidness, feathery tube pipe conifers, and a band of dagger-shaped needle sticks on anode/cathode electrode surfaces provides high performance LIB modules. The geodetically-shaped anode/cathode design enables the uniqueness of all LIB module configurations in terms of powerful lithium ion (Li+) movement revolving in out-/in- and up-/downward diffusion regimes and in hovering electron density for high-speed discharge rates. The stability of built-in anode//cathode full-scale LIB-model meso-geodesics affords an outstanding long-term cycling performance. The full-cell LIB meso-geodesics offered 91.5% retention of the first discharge capacity of 165.8 mAhg−1 after 2000 cycles, Coulombic efficiency of ~99.6% at the rate of 1 C and room temperature, and high specific energy density of ≈119 Wh kg−1. This LIB meso-geodesic module configuration may align perfectly with the requirements of the energy density limit mandatory for long-term EV driving range and the scale-up commercial manufactures.

scholarly journals On-board Electrical, Electronics and Pose Estimation System for Hyperloop Pod Design

2020 ◽  
Author(s):  
Prathamesh Saraf ◽  
Nihal Singh ◽  
Plava Kattamuri ◽  
Jay Karhade ◽  
Ishika Bhattacharya
Keyword(s):  
Pose Estimation ◽  
High Speed ◽  
Discharge Rate ◽  
Estimation Algorithm ◽  
High Energy ◽  
High Energy Density ◽  
Electrical System ◽  
Computationally Efficient ◽  
Metropolitan Cities ◽  
Estimation System

Hyperloop is a high-speed ground-based transportation system utilizing sealed tubes, with the aim of ultimately transporting passengers between metropolitan cities in efficiently designed autonomous capsules. In recent years, the design and development of sub-scale prototypes for these Hyperloop pods has set the foundation for realizing more practical and scalable pod architectures. This paper proposes a practical, power and space optimized on-board electronics architecture, coupled with an end-to-end computationally efficient pose estimation algorithm. Considering the high energy density and discharge rate of onboard batteries, this work additionally presents a robust system for fault detection, protection and management of batteries, along with the design of the surrounding electrical system. Performance evaluation and verification of proposed algorithms and circuits has been carried out by software simulations using both Python and Simulink.

Permeability Performance on Porous Structure of Injection Mold Fabricated by Metal Laser Sintering Combined with High Speed Milling

2012 ◽  
Vol 6 (5) ◽  
pp. 576-583 ◽  
Author(s):  
Hiroyuki Narahara ◽  
◽  
Sho Takeshita ◽  
Hirofumi Fukumaru ◽  
Hiroshi Koresawa ◽  
...  
Keyword(s):  
Porous Media ◽  
Laser Beam ◽  
High Speed ◽  
High Energy ◽  
Laser Sintering ◽  
High Energy Density ◽  
Airflow Rate ◽  
Macroporous Structure ◽  
High Speed Milling ◽  
Ordered Macroporous

Metal Laser Sintering Combined with High Speed Milling is the technology in which high speed cutting is united with the selective laser sintering process. By changing the conditions of laser beam irradiation, it is possible to build a sintered porous media which has a hole in an arbitrary part by this process. If the mold tool of this structure is used for injection molding, it is proved that the compressed air imprisoned in the mold and the gas coming out of resin are discharged from it, poor molding can be reduced. However, as sintered porous media is hard to control for the size and position of an ordered macroporous structure, it is difficult to build porous media with an ordered macroporous structure deliberately. This results in a smaller amount of airflow and a greater variation in airflow. In order to solve this problem, latticework is proposed as a new gas permeable structure in this paper. Different from a lower density sintered structure, metallic powder is sintered and fused using a laser beam with a high energy density, and fusion is carried out into the latticework structure. The fused gaps of the structure serve as a hole. Since each hole will keep the position and become the ordered macroporous structure even if lamination continues, the improvement in performance of gas permeability is expected. The airflow equation for the structural design to satisfy a required airflow rate is also examined in this paper.

Sign in / Sign up

Export Citation Format

Share Document