Direct ink writing of 3D thermoelectric architectures for fabrication of micro power generators

Abstract Micro-thermoelectric modules can be used to develop unique components such as energy harvesters, active coolers, and thermal sensors in various integrated systems. However, the manufacturing of these modules still relies on costly traditional micro-fabrication processes, producing only two-dimensional (2D) thermoelectric films. This limitation severely constrains temperature gradient formation across thermoelectric films, and hence, the sufficient amount of power required to run integrated systems is not generated. Herein, we present the direct ink writing of micro-scale three-dimensional (3D) thermoelectric architectures for fabricating high-performance micro-thermoelectric generators. The characteristics of (Bi, Sb)2(Te, Se)3-based particles were precisely engineered such that the colloidal inks achieved outstanding viscoelasticity, thereby facilitating the creation of complex 3D architectures having high thermoelectric figure-of-merits of 1.1 (p-type) and 0.5 (n-type). Micro-thermoelectric generators made of 3D-written vertical filaments exhibited large temperature gradients and a good resulting power density, opening an avenue for the cost-effective and rapid manufacturing of integrated micro-thermoelectric modules.

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Three-Dimensional Aerodynamic Analysis of a Darrieus Wind Turbine Blade Using Computational Fluid Dynamics and Lifting Line Theory

Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy ◽

10.1115/gt2017-64701 ◽

2017 ◽

Author(s):

Francesco Balduzzi ◽

Alessandro Bianchini ◽

Giovanni Ferrara ◽

David Marten ◽

George Pechlivanoglou ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

High Performance ◽

Three Dimensional ◽

Unsteady Aerodynamics ◽

Cost Effective ◽

Navier Stokes ◽

Line Theory ◽

Wake Model ◽

Lifting Line

Due to the rapid progress in high-performance computing and the availability of increasingly large computational resources, Navier-Stokes computational fluid dynamics (CFD) now offers a cost-effective, versatile and accurate means to improve the understanding of the unsteady aerodynamics of Darrieus wind turbines and deliver more efficient designs. In particular, the possibility of determining a fully resolved flow field past the blades by means of CFD offers the opportunity to both further understand the physics underlying the turbine fluid dynamics and to use this knowledge to validate lower-order models, which can have a wider diffusion in the wind energy sector, particularly for industrial use, in the light of their lower computational burden. In this context, highly spatially and temporally refined time-dependent three-dimensional Navier-Stokes simulations were carried out using more than 16,000 processor cores per simulation on an IBM BG/Q cluster in order to investigate thoroughly the three-dimensional unsteady aerodynamics of a single blade in Darrieus-like motion. Particular attention was payed to tip losses, dynamic stall, and blade/wake interaction. CFD results are compared with those obtained with an open-source code based on the Lifting Line Free Vortex Wake Model (LLFVW). At present, this approach is the most refined method among the “lower-fidelity” models and, as the wake is explicitly resolved in contrast to BEM-based methods, LLFVW analyses provide three-dimensional flow solutions. Extended comparisons between the two approaches are presented and a critical analysis is carried out to identify the benefits and drawbacks of the two approaches.

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Three-Dimensional Aerodynamic Analysis of a Darrieus Wind Turbine Blade Using Computational Fluid Dynamics and Lifting Line Theory

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4037750 ◽

2017 ◽

Vol 140 (2) ◽

Cited By ~ 6

Author(s):

Francesco Balduzzi ◽

David Marten ◽

Alessandro Bianchini ◽

Jernej Drofelnik ◽

Lorenzo Ferrari ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

High Performance ◽

Three Dimensional ◽

Unsteady Aerodynamics ◽

Cost Effective ◽

Navier Stokes ◽

Line Theory ◽

Wake Model ◽

Lifting Line

Due to the rapid progress in high-performance computing and the availability of increasingly large computational resources, Navier–Stokes (NS) computational fluid dynamics (CFD) now offers a cost-effective, versatile, and accurate means to improve the understanding of the unsteady aerodynamics of Darrieus wind turbines and deliver more efficient designs. In particular, the possibility of determining a fully resolved flow field past the blades by means of CFD offers the opportunity to both further understand the physics underlying the turbine fluid dynamics and to use this knowledge to validate lower-order models, which can have a wider diffusion in the wind energy sector, particularly for industrial use, in the light of their lower computational burden. In this context, highly spatially and temporally refined time-dependent three-dimensional (3D) NS simulations were carried out using more than 16,000 processor cores per simulation on an IBM BG/Q cluster in order to investigate thoroughly the 3D unsteady aerodynamics of a single blade in Darrieus-like motion. Particular attention was paid to tip losses, dynamic stall, and blade/wake interaction. CFD results are compared with those obtained with an open-source code based on the lifting line free vortex wake model (LLFVW). At present, this approach is the most refined method among the “lower-fidelity” models, and as the wake is explicitly resolved in contrast to blade element momentum (BEM)-based methods, LLFVW analyses provide 3D flow solutions. Extended comparisons between the two approaches are presented and a critical analysis is carried out to identify the benefits and drawbacks of the two approaches.

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High Performance Solar Thermoelectric Generator Using Asymmetrical Variable Leg Geometries

E3S Web of Conferences ◽

10.1051/e3sconf/202123900005 ◽

2021 ◽

Vol 239 ◽

pp. 00005

Author(s):

Chika Maduabuchi ◽

Kevwe Ejenakevwe ◽

Agwu Ndukwe ◽

Chigbo Mgbemene

Keyword(s):

Temperature Gradient ◽

High Performance ◽

Thermoelectric Generator ◽

Computational Study ◽

Thermoelectric Generators ◽

Variable Geometry ◽

Electric Voltage ◽

Thermoelectric Modules ◽

Solar Thermoelectric Generator ◽

Solar Thermoelectric Generators

This paper presents a computational study of the combined effects of variable geometry and asymmetry in the legs of thermocouples of thermoelectric modules used in solar thermoelectric generators (STEGs). Six different models were considered for the thermocouples in each module, namely: rectangular-rectangular legs, rectangular-trapezoidal legs, rectangular-X legs, trapezoidal-trapezoidal legs, trapezoidal-X legs, and X-X legs. Simulations of the six different modules under the same heat flux was carried out in ANSYS 2020 R2 software. Temperature and voltage distributions were obtained for each model and the results indicate significant variations due to the utilization of varying leg geometries. Results show that the X-X leg module generated the highest temperature gradient and electric voltage. In comparison, a temperature gradient and electric voltage of 297 K and 16 V, respectively were achieved with the X-X leg module as against 182 K and 8.4 V, respectively, achieved in a conventional rectangular leg module. This suggests a 63.2% and 90.5% increase in the temperature gradient and electric voltage of the conventional TE module. Therefore, this study demonstrates that X geometry gives the best performance for thermoelectric modules and STEGs.

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A one-step, cost-effective green method to in situ fabricate Ni(OH)2 hexagonal platelets on Ni foam as binder-free supercapacitor electrode materials

Journal of Materials Chemistry A ◽

10.1039/c4ta05156d ◽

2015 ◽

Vol 3 (5) ◽

pp. 1953-1960 ◽

Cited By ~ 130

Author(s):

Lingjie Li ◽

Jing Xu ◽

Jinglei Lei ◽

Jie Zhang ◽

Frank McLarnon ◽

...

Keyword(s):

High Performance ◽

Electrode Materials ◽

Three Dimensional ◽

Cost Effective ◽

Ni Foam ◽

Supercapacitor Electrode ◽

One Step ◽

Binder Free ◽

Supercapacitor Electrode Materials

The Ni(OH)2 hexagonal platelets were in situ fabricated on Ni foam as a binder-free supercapacitor electrode material with high performance and excellent cycling stability by a one-step, cost-effective, green hydrothermal treatment of three-dimensional (3D) Ni foam in a 15 wt% H2O2 aqueous solution.

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Spray Pyrolyzed TiO2 Embedded Multi-Layer Front Contact Design for High-Efficiency Perovskite Solar Cells

Nano-Micro Letters ◽

10.1007/s40820-020-00559-2 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Md. Shahiduzzaman ◽

Mohammad Ismail Hossain ◽

Sem Visal ◽

Tetsuya Kaneko ◽

Wayesh Qarony ◽

...

Keyword(s):

Solar Cells ◽

High Performance ◽

High Efficiency ◽

Photovoltaic Performance ◽

Perovskite Solar Cells ◽

Three Dimensional ◽

Cost Effective ◽

Transport Layer ◽

Electron Transport Layer ◽

Single Junction

AbstractThe photovoltaic performance of perovskite solar cells (PSCs) can be improved by utilizing efficient front contact. However, it has always been a significant challenge for fabricating high-quality, scalable, controllable, and cost-effective front contact. This study proposes a realistic multi-layer front contact design to realize efficient single-junction PSCs and perovskite/perovskite tandem solar cells (TSCs). As a critical part of the front contact, we prepared a highly compact titanium oxide (TiO2) film by industrially viable Spray Pyrolysis Deposition (SPD), which acts as a potential electron transport layer (ETL) for the fabrication of PSCs. Optimization and reproducibility of the TiO2 ETL were discreetly investigated while fabricating a set of planar PSCs. As the front contact has a significant influence on the optoelectronic properties of PSCs, hence, we investigated the optics and electrical effects of PSCs by three-dimensional (3D) finite-difference time-domain (FDTD) and finite element method (FEM) rigorous simulations. The investigation allows us to compare experimental results with the outcome from simulations. Furthermore, an optimized single-junction PSC is designed to enhance the energy conversion efficiency (ECE) by > 30% compared to the planar reference PSC. Finally, the study has been progressed to the realization of all-perovskite TSC that can reach the ECE, exceeding 30%. Detailed guidance for the completion of high-performance PSCs is provided.

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Simple Self-Assembly Strategy of Nanospheres on 3D Substrate and Its Application for Enhanced Textured Silicon Solar Cell

Nanomaterials ◽

10.3390/nano11102581 ◽

2021 ◽

Vol 11 (10) ◽

pp. 2581

Author(s):

Dan Su ◽

Lei Lv ◽

Yi Yang ◽

Huan-Li Zhou ◽

Sami Iqbal ◽

...

Keyword(s):

Self Assembly ◽

High Performance ◽

Light Trapping ◽

Incident Light ◽

Three Dimensional ◽

Cost Effective ◽

Optical Measurements ◽

Sio2 Coating ◽

Assembly Strategy ◽

Cost Effective Approach

Nanomaterials and nanostructures provide new opportunities to achieve high-performance optical and optoelectronic devices. Three-dimensional (3D) surfaces commonly exist in those devices (such as light-trapping structures or intrinsic grains), and here, we propose requests for nanoscale control over nanostructures on 3D substrates. In this paper, a simple self-assembly strategy of nanospheres for 3D substrates is demonstrated, featuring controllable density (from sparse to close-packed) and controllable layer (from a monolayer to multi-layers). Taking the assembly of wavelength-scale SiO2 nanospheres as an example, it has been found that textured 3D substrate promotes close-packed SiO2 spheres compared to the planar substrate. Distribution density and layers of SiO2 coating can be well controlled by tuning the assembly time and repeating the assembly process. With such a versatile strategy, the enhancement effects of SiO2 coating on textured silicon solar cells were systematically examined by varying assembly conditions. It was found that the close-packed SiO2 monolayer yielded a maximum relative efficiency enhancement of 9.35%. Combining simulation and macro/micro optical measurements, we attributed the enhancement to the nanosphere-induced concentration and anti-reflection of incident light. The proposed self-assembly strategy provides a facile and cost-effective approach for engineering nanomaterials at 3D interfaces.

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Spray-printed CNT/P3HT organic thermoelectric films and power generators

Journal of Materials Chemistry A ◽

10.1039/c5ta06096f ◽

2015 ◽

Vol 3 (43) ◽

pp. 21428-21433 ◽

Cited By ~ 75

Author(s):

Cheon Taek Hong ◽

Young Hun Kang ◽

Juwhan Ryu ◽

Song Yun Cho ◽

Kwang-Suk Jang

Keyword(s):

Carbon Nanotube ◽

High Performance ◽

Nanocomposite Films ◽

Thermoelectric Generators ◽

Power Generators

We report the fabrication of high-performance thermoelectric carbon nanotube/poly(3-hexylthiophene) (CNT/P3HT) nanocomposite films and flexible CNT/P3HT organic thermoelectric generators by spray-printing.

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