Double-layer Channel Research Articles

Numerical simulation of thermal performance of cold plates for high heat flux electronics cooling

High heat flow density electronic components need cooling plates with strong heat exchange capacity to maintain temperature balance. To obtain better cooling performance, four different flow channel types of cooling plates are designed, including an S-type channel, Z-type channel, mosaic channel and double-layer channel. The maximum temperature of the cooling plate, outlet temperature and pressure drop under different working conditions and coolant are analyzed by numerical simulation. The simulation results show that the double-layer channel design can effectively enhance the heat transfer effect of the cooling plate and reduce the pressure drop. The maximum temperature of the cooling plate of the double-layer flow channel is 6.88 ?C lower than that of the Z-type flow channel. Moreover, increasing the inlet flow rate and lowering the coolant inlet temperature can improve the cooling performance of the cold plate, but increasing the inlet flow rate will lead to an increase in the pressure loss of the cold plate. When the coolant of the dou?ble-layer channel cooling plate is 20% ethylene glycol-water solution, the cooling performance is better than the other three coolants. Other channel cooling plates perform better with water as the coolant.

Mobility Enhancement of BCE-Type Amorphous InGaZnO TFTs Using Triple-Layer Channels

The back-channel-etch-type amorphous InGaZnO (a-IGZO) triple-layer thin-film transistor (TL-TFT) consists of a top barrier and a bottom barrier deposited with oxygen flow (OF) and an a-IGZO main channel deposited without OF in between. The TL-TFT has 1.7 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> and 1.3 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> electron mobilities for the bottom gate (BG) operation as compared to the single-layer and double-layer channel TFTs, respectively. The conduction band difference between the barrier layers and the main channel is high enough to confine the carriers in the main channel. The bottom barrier decreases the Coulomb scattering and the surface roughness scattering to increase the mobility, while the top barrier decreases the plasma-induced damage in the channel and the bottom barrier. However, both the hysteresis and subthreshold swing (S.S.) increase if only the bottom barrier is adopted double-layer TFT (DL-TFT) because the shallow states in the IGZO bottom barrier provide extra tunneling paths for the electrons to be trapped inside the BG oxide. With additional top barrier structure, plasma-induced damage in the main channel and the bottom barrier can be mitigated to reduce the degradation of hysteresis and S.S. Moreover, the TL-TFTs demonstrate better reliability under both positive bias stress and negative bias illumination stress than single-layer TFTs (SL-TFTs) and DL-TFTs.

Effect of Heat Transfer Performance and Thermodynamic Analysis of Complex Structured Double-layer Microchannels Heat Sink

As microelectronics become more and more integrated, in order to solve the increasingly serious microelectronic heat dissipation problem. Design of a complex structure with a double layer channel. The upper layer is a rectangular channel and the lower layer is a complex structure of the design. The DLCF (double layer counter flow) and SLCF (single layer counter flow) are compared numerically. The innovative design suggested in this paper is contrasted with the upper and lower layers, which are both rectangular channels. The simulation is carried out using FLUENT software. Based on previous studies, the concept of enhanced heat transfer coefficient was used to predict the heat transfer efficiency of channels. The friction factor, Reynolds number, as well as the temperature and thermal resistance along the channel are derived. From the results, it is clear that the complex structure of the double-layered channel designed in this paper has a higher heat transfer efficiency. The enhanced heat transfer factor number is higher.

Fuzzy modelling and metaheuristic to minimize the temperature of lithium-ion battery for the application in electric vehicles

The recent progress in the electric vehicles requires developing an efficient battery that can be fast charged and having a longer lifetime. Proper thermal management of the battery systems plays a key factor in the performance and lifetime of batteries. Liquid cooling is one of the feasible methods for effective thermal management of battery systems. In this work, the optimal size of double-layer reverting channel is determined using fuzzy modelling and modern optimization. A novel application of the Slime mould algorithm (SMA) is suggested to find the best size of double-layer cooling channel that can simultaneously minimize battery's temperature, better uniform of battery's temperature, and lower energy consumption. For first time, an accurate fuzzy model of the double-layer channel in terms of four dimensions parameters (width ratio, length ratio of x axis, length ratio of y axis, and thickness of all channels) is successfully obtained. The average coefficient of determination values are 1.0 and 0.8214 respectively for training and testing. Also, the average RMSE values 9.32E-06 and 0.018 respectively for training and testing High coefficient-of-determination values and low for RMSE values both training and testing phases confirmed the accuracy of the model. Then, SMA is used to determine optimal size of the cooling channel to minimize simultaneously the temperature, surface standard deviation, and pressure drop. The results confirmed the accuracy of the proposed fuzzy model in addition to the performance improvement. The overall performance is improved by 7.8% through minimizing the maximum temperature and well thermal distribution.

Ultrathin Sub-5-nm Hf₁₋ₓZrₓO₂ for a Stacked Gate-all-Around Nanowire Ferroelectric FET With Internal Metal Gate

This study investigates a device’s ability to boost its on-state current and subthreshold behavior using a ferroelectric field-effect transistor (FeFET) with an ultrathin sub-5-nm Hf <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-<i>x</i></sub> Zr <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> O2 (HZO). A conventional field-effect transistor (FET) with pure hafnium (HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) is used as a control measure and the impact of an internal metal gate (IMG) is also discussed. The study was conducted by using a sub-5-nm HZO and seed layer to fabricate a gate-all-around (GAA) nanowire (NW); a FeFET with a metal-ferroelectric–metal-insulator-semiconductor (MFMIS) structure; and a double layer (DL) of the channel. The channel size used in the experiment was approximately <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$9.6\times16$ </tex-math></inline-formula> nm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and the total thickness of the gate stack was 9.2 nm. This thickness is 50.5% less than our previous experiment. The FeFET exhibits a considerably high <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{on}$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{off}$ </tex-math></inline-formula> ratio exceeding 107. The IMG serves as a potential equalizer and the ferroelectric material is arranged in a more symmetrical electric field. This results in a lower subthreshold (sub- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{TH}$ </tex-math></inline-formula> ) swing ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S.S._{min}=$ </tex-math></inline-formula> 49.3mV/decade) with a wide range ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{3}$ </tex-math></inline-formula> ) of drain currentcompared to that without an IMG. The findings indicate that a high-performance GAA FET can be achieved by combining a DL channel, GAA NW, ferroelectric material, and an IMG.

Flow and thermal performance of supercritical n-decane in double-layer channels for regenerative cooling of a scramjet combustor

In order to improve the active regenerative cooling performance of a scramjet using supercritical n-decane, a new type of cooling channel, the double-layer channel, is proposed. Based on reliable numerical simulations, temperature profiles, fluid flow track, vortex structure and buoyancy force distribution of three cases are presented, respectively. It is found that the heat transfer performance of the double-layer channel with the same flow direction is better than the other cases and the heat transfer deterioration (HTD) phenomenon is effectively weakened and the wall temperature is greatly reduced. A cross-flow and a large vortex structure induced by the buoyancy forces are helpful to the occurrence of the HTD phenomenon. An “M” type temperature profile and an “M” type buoyancy force distribution are important characteristics of the HTD phenomenon.

Highly Stable AlInZnSnO and InZnO Double-Layer Oxide Thin-Film Transistors With Mobility Over 50 $\text{cm}^{2}/\text{V} \cdot \text{s}$ for High-Speed Operation

We present high-mobility back channel etch Al–In–Zn–Sn–O/In–Zn–O (IZO) double-layer channel thin-film transistors (TFTs). The field-effect mobility of 53.2 $\text{cm}^{2}/\text{V} \cdot \text{s}$ , threshold voltage of 0.5 V, and subthreshold swing of 0.15 V/decade were obtained with a thin IZO-inserted double-layer channel TFT. The positive bias stability was improved with an IZO-inserted double-layer channel. We fabricated 13-stage ring oscillators, which exhibited an oscillating frequency of 296 kHz at ${V} _{\text {DD}} = {20}$ . These results demonstrate that the proposed double-layer channel oxide TFT can be used for demanding applications such as backplane devices for ultrahigh resolution display.

An ultrasensitive fluorescent biosensor using high gradient magnetic separation and quantum dots for fast detection of foodborne pathogenic bacteria

Rapid screening of contaminated foods is the key to prevent and control the outbreaks of foodborne diseases. In this study, a novel fluorescent biosensor was developed for ultrasensitive and rapid detection of E. coli O157:H7. The proposed fluorescent biosensor used the double-layer channel with the immune magnetic nanoparticles (MNPs) for specific separation and efficient concentration of the target bacteria, and the immune quantum dots (QDs) with the portable optical system for quantitative detection of the bacteria. First, the bacteria were captured by the immune MNPs in the channel at the presence of the high gradient magnetic fields (HGMFs) to form the MNP-bacteria complexes. Then, the immune QDs were used to react with the target bacteria to form the MNP-bacteria-QDs complexes in the channel. Finally, the enriched complexes were collected and detected using the portable optical system to obtain the fluorescence intensity for final determination of the E. coli O157:H7 cells in the sample. This proposed biosensor was demonstrated to be able to detect E. coli O157:H7 as low as 14 CFU/mL within 2 h. The recovery of E. coli in the spiked milk samples ranged from 95.92% to 108.15%, indicating that it was capable of detecting E. coli in real samples. Besides, this proposed biosensor was able to detect the bacteria in the volume of 10 mL, and has the potential to detect the bacteria in a larger volume to increase the sensitivity.

Enhanced particle self-ordering in a double-layer channel.

In this work, a novel double-layer microfluidic device for enhancing particle focusing was presented. The double-layer device consists of a channel with expansion-contraction array and periodical slanted grooves. The secondary flows induced by the grooves modulate the flow patterns in the expansion-contraction-array (ECA) channel, further affecting the particle migration. Compared with the single ECA channel, the double-layer channel can focus the particles over a wider range of flow rate. Due to the differentiation of lateral migration, the double-layer channel is able to distinguish the particles with different sizes. Furthermore, the equilibrium positions could be modulated by the orientation of grooves. This work demonstrates the possibility to enhance and adjust the inertial focusing in an ECA channel with the assistance of grooves, which may provide a simple and portable platform for downstream filtration, separation, and detection.

Enhanced long-distance transport of periodic electron beams in an advanced double layer cone-channel target

An enhanced long-distance transport of periodic electron beams in an advanced double layer cone-channel target is investigated using two-dimensional particle-in-cell simulations. The target consists of a cone attached to a double-layer hollow channel with a near-critical-density inner layer. The periodic electron beams are generated by the combination of ponderomotive force and longitudinal laser electric field. Then a stable electron propagation is achieved in the double-layer channel over a much longer distance without evident divergency, compared with a normal cone-channel target. Detailed simulations show that the much better long-distance collimation and guidance of energetic electrons is attributed to the much stronger electromagnetic fields at the inner wall surfaces. Furthermore, a continuous electron acceleration is obtained by the more intense laser electric fields and extended electron acceleration length in the channel. Our investigation shows that by employing this advanced target, both the forward-going electron energy flux in the channel and the energy coupling efficiency from laser to electrons are about threefold increased in comparison with the normal case.

Preparation of Amphotericin B-Ergosterol structures and molecular simulation of water adsorption and diffusion

In this study, molecular simulation was used to explore the structural characteristics and water transport performance of Amphotericin B-Brgosterol (AmBEr) channels. A molecular dynamics (MD) technique was used to construct two types of molecular models of AmBEr channels: single-layer channel (SLC) and double-layer channel (DLC). A MD simulation was used to illustrate the differences between SLC and DLC AmBEr models with respect to structure, channel diameter, interior affinity, and transportation behavior of water molecules. A Monte Carlo (MC) method was adopted to investigate the sorption behavior in these two types of AmBEr channels. The intramolecular properties and intermolecular interactions indicated the feasibility of the simple model construction method adopted in this study. The internal diameter and channel shape showed that the use of funnel-type AmBEr channels would lead to high levels of permeability and selectivity. The special tunnel shape was reflected in the diffusion calculation that resulted in a high displacement of water molecules in two types of channel models. The water molecule-channel hydrogen bond distribution and snapshot analyses of the adsorption site revealed an affinity between the amphotericin B monomer and water molecules. The novel chemical structure of the amphotericin B monomer features simultaneous hydrophilic and hydrophobic segments. This particular structural characteristic was reflected in the unique shape of the water adsorption isotherm curves, which show a unique three-step increase in equilibrated water pressure. In transport prediction, two AmBEr models had similar permeability values but different water transport mechanisms. Concisely, fabrication of the artificial water channel would help to enhance the water permeability in the water transport process. The results from the simulation provided valuable information for structural characterization and in estimating the transport behavior of the molecules in the AmBEr channels.

P-9: High Performance Back Channel Etch Metal Oxide Thin-film Transistor with Double Active Layers

We fabricated high performance back channel etch (BCE) IZO/AIZTO double-layer channel oxide thin-film transistors (TFTs) and analyzed their electrical characteristics and photostability of the devices. The field-effect mobility of 53.2 cm2/Vs was obtained, and we expect IZO/AIZTO double-layer BCE TFT can be used as a backplane devices for next generation high performance display applications.

Improved Mobility and Bias Stability of Thin Film Transistors Using the Double-Layer a-InGaZnO/a-InGaZnO:N Channel.

The amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistors (TFTs) were demonstrated based on a double-layer channel structure, where the channel is composed of an ultrathin nitro-genated a-IGZO (a-IGZO:N) layer and an undoped a-IGZO layer. The double-layer channel device showed higher saturation mobility and lower threshold-voltage shift (5.74 cm2/Vs, 2.6 V) compared to its single-layer counterpart (0.17 cm2/Vs, 7.23 V). The improvement can be attributed to three aspects: (1) improved carrier transport properties of the channel by the a-IGZO:N layer with high carrier mobility and the a-IGZO layer with high carrier concentration, (2) reduced interfacial trap density between the active channel and the gate insulator, and (3) higher surface flatness of the double-layer channel. Our study reveals key insights into double-layer channel, involving selecting more suitable electrical property for back-channel layer and more suitable interface modification for active layer. Meanwhile, room temperature fabrication amorphous TFTs offer certain advantages on better flexibility and higher uniformity over a large area.

Double-Layer Flow Channel Insert for Electric and Thermal Insulation in the Dual-Coolant Lead-Lithium Blanket

A new modification of the flow channel insert (FCI) called “double-layer” or “nested” FCI (nFCI) is assessed numerically for the poloidal duct flows in the dual-coolant lead-lithium (DCLL) blanket under the US DEMO outboard (OB) blanket conditions. The proposed nFCI mitigates the thermal stress while providing sufficient thermal insulation and reducing the MHD pressure drop.

Double-layered magnetooptic channel waveguide for waveguide isolator application

TE-TM mode conversion based on the nonreciprocal Faraday effect for waveguides fabricated by liquid-phase epitaxially grown (YBiCa)/sub 3/Fe/sub 5/O/sub 12/ films is discussed. The phase mismatch is controlled by constructing a double-layer channel waveguide with an intermediate cladding layer of refractive index slightly lower than the core. Care must be taken to compensate any birefringence of materials, e.g. stress- and growth-induced birefringence. It is shown that such a structure is effective in decreasing the effect of waveguide shape deformation on the phase-matching degree. The analysis of the double-layered channel waveguide and experimental results are described.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>