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The integration of solar interfacial evaporation and power generation offers a sustainable solution to address water and electricity scarcity. Although water‐power cogeneration schemes are proposed, the existing schemes lack scalability, flexibility, convenience, and stability. These limitations severely limit their future industrial applications. In this study, we prepared a hybrid fabric composed of basalt fibers and cotton yarns with asymmetric structure using textile weaving technology. The cotton yarn in lower layer of fabric facilitates water transport, while the basalt fibers in upper layer enable thermal localization and water supply balancing. The carbon black is deposited on top layer by flame burning to facilitate photothermal conversion. The fabric exhibits a high evaporation rate of 1.52 kg m−2 h−1, which is 3.6 times that of pure water, and an efficiency of 88.06% under 1 kW m−2 light intensity. After assembly with a thermoelectric module, the hybrid system achieves a maximum output power density of 66.73 mW m−2. By exploiting the scalability of fabric, large‐scale desalination and power production can be achieved in outdoor environments. This study demonstrates the seamless integration of fabric‐based solar evaporation and waste heat‐to‐energy technologies, thereby providing new avenues for the development of scalable and stable water‐power cogeneration systems. [ABSTRACT FROM AUTHOR]

Microstructures and thermoelectric properties of porous Ca 3 Co 4 O 9 ceramics were investigated, which were prepared by tert-butanol alcohol (TBA)-based freeze casting method. The honeycomb-like porous Ca 3 Co 4 O 9 ceramic presented an average pore diameter of 2.5 μm and the porosity of 65 %. The excellent low total thermal conductivity of 0.354 W (m K)−1 was obtained along the parallel channel direction, which was attributed to the oriented pores and isolated pores dispersed in ceramics matrix. The compositing thermal conductivity behavior of porous Ca 3 Co 4 O 9 ceramics was jointly regulated by the parallel and Maxwell-Eucken (ME-1) models. The ZT value reached 0.37 at 1073 K. This work provides an effective strategy to improve thermoelectric properties of oxides thermoelectric ceramics, which can complete the decoupling of electrical and thermal properties. [ABSTRACT FROM AUTHOR]

With buildings representing a substantial portion of global energy consumption, exploring alternatives to traditional fossil fuel-based heating and cooling systems is critical. Thermoelectricity offers a promising solution by converting temperature differentials into electrical voltage or vice versa, enabling efficient indoor thermal regulation. This paper presents a comprehensive investigation into the integration of thermoelectric wall systems for sustainable building climate control through numerical simulations and experimental analyses. Numerical simulations using computational fluid dynamics (CFD) techniques were conducted to model fluid flow and heat transfer within the thermoelectric wall systems under various operating conditions. These simulations provided insights into the system's thermal behavior, which were validated through experimental setups designed to measure temperature differentials, airflow rates, and power consumption. The results showed that power consumption is directly correlated with electrical current, ranging from 0.19 W to 77.4 W as the current increased from 0.1 A to 2 A. Additionally, the heat absorbed by the system increased significantly with electrical current, by 706–1044%, depending on the air velocity. The thermal energy released from the hot side of the thermoelectric modules also rose substantially, ranging from 9850 to 5285% with increasing electrical current, and from 275 to 51% with higher air velocities. Moreover, increasing air velocity led to a 6.78–9.37% reduction in power consumption for currents between 0.1 A and 2 A. The coefficient of performance (COP) analysis revealed that optimizing both electrical current and air velocity is essential for maximizing system efficiency. While fan power consumption reduces COP at higher air velocities, neglecting fan power consumption results in COP improvements ranging from 6.5 × 10⁻⁴ to 49.0%. These findings highlight the potential of thermoelectric wall systems to enhance indoor comfort and energy efficiency in buildings. [ABSTRACT FROM AUTHOR]

Composites consisting of two nano-or molecular-scale components tend to exhibit newer properties or characterizations compared to the matrix material. However, they are extremely limited in thermoelectricity due to the difficulty of achieving an extremely homogeneous distribution of the material on such a small scale. In this paper, we successfully prepared a series of composite thermoelectric materials of Sr 0.9 La 0.1 Ti 0.85 Nb 0.15 O 3 /carbon nanotubes (CNTs, with contents of 0.5, 1.5, 2.5, and 5.0 wt%). Highly homogeneous dispersion of CNTs was observed in the strontium titanate oxide (SrTiO 3) matrix prepared via high-temperature and high-pressure (HPHT) synthesis due to the interaction between SrTiO 3 and multi-walled CNTs. The experimental results showed that CNTs were uniformly dispersed in the composite powders synthesized using the HPHT method. Meanwhile, the electrical conductivity increased linearly with the increase in the CNTs content. The power factor reached 684 μWm−1K−2 at 973K with 2.5 wt% CNTs composite concentration. This considerable enhancement is attributed to the increase in the charge carrier concentration as well as the higher electron mobility. In addition, the lattice thermal conductivity was suppressed due to enhanced Umklapp scattering. This ultimately leads to a thermoelectric figure of merit, zT , of 0.33 at 973 K. This work opens a new window on the thermoelectric properties of nanocomposite SrTiO 3 -based thermoelectric materials. [ABSTRACT FROM AUTHOR]

Skin‐like electronics research aiming to mimic even surpass human‐like specific tactile cognition by operating perception‐to‐cognition‐to‐feedback of stimulus to build intelligent cognition systems for certain imperceptible or inappreciable signals was so attractive. Herein, we constructed an all‐in‐one tri‐modal pressure sensing wearable device to address the issue of power supply by integrating multistage microstructured ionic skin (MM i‐skin) and thermoelectric self‐power staffs, which exhibits high sensitivity simultaneously. The MM i‐skin with multi‐stage "interlocked" configurations achieved precise recognition of subtle signals, where the sensitivity reached up to 3.95 kPa−1, as well as response time of 46 ms, cyclic stability (over 1500 cycles), a wide detection range of 0–200 kPa. Furthermore, we developed the thermoelectricity nanogenerator, piezoelectricity nanogenerator, and piezocapacitive sensing as an integrated tri‐modal pressure sensing, denoted as P‐iskin, T‐iskin, and C‐iskin, respectively. This multifunctional ionic skin enables real‐time monitoring of weak body signals, rehab guidance, and robotic motion recognition, demonstrating potential for Internet of things (IoT) applications involving the artificial intelligence‐motivated sapiential healthcare Internet (SHI) and widely distributed human‐machine interaction (HMI). [ABSTRACT FROM AUTHOR]

There is still a lack of effective lubrication condition monitoring methods in the field of diesel engines. The paper proposes a novel thermoelectric approach to divide the lubrication state of bearings. First, the generation mechanism of thermoelectric potential on bearings is clarified. Then, both experimental and simulation studies are done, and a strong correlation between lubrication and thermoelectric potential is shown. The film thickness and temperature are further confirmed as significant factors influencing thermoelectric potential. Generally, the thermoelectric potential increases with temperature. However, a small film thickness ratio (when the film thickness ratio is less than 4) will suppress the thermoelectric potential. Three typical lubrication states of bearings are distinguished through thermoelectric potential and supported by the Stribeck curve results. Moreover, the significant influence of lubrication on the bearing is confirmed through the analysis of surface morphology and composition. [ABSTRACT FROM AUTHOR]

A theoretical prediction of the contribution to the thermo-electromotive force (thermo-EMF) of a thermocouple due to the minority charge carriers in both legs is presented. This prediction is made on the assumption that, at any time, the electrical conductivity of the majority charge carriers σ M remains very large compared to the electrical conductivity of the minority carriers σ m ( σ M ≫ σ m ). The expression has also been analyzed in order to find strategies to reduce its negative impact on the thermo-EMF of the thermocouple. Finally, calculations were carried out in the case of the thermocouple made of silicon thermoelements. The results show that the presence of minority carriers in the thermocouple legs can either positively or negatively affect the generated thermo-EMF. Whenever the contribution is negative, its magnitude may be reduced by widening the bandgap of the N-type leg and/or narrowing that of the p-type leg, adjusting the length of the legs, or intensifying recombinations on the surfaces of the P-type leg [ABSTRACT FROM AUTHOR]

The possible contribution of phonon drag effect to the thermoelectrically sustained potential of a heated nanoisland on a semiconductor surface was estimated in a first principal consideration. We regarded electrons and phonons as interacting particles, and the interaction cross-section was derived from the basic theory of semiconductors. The solution of the equation of motion for average electrons under the simultaneous action of phonon drag and electric field gave the distributions of phonon flux, density of charge carriers and electric potential. Dimensional suppression of thermal conductance and electron-phonon interaction were accounted for but found to be less effective than expected. The developed model predicts the formation of a layer with a high density of charge carriers that is practically independent of the concentration of dopant ions. This layer can effectively intercept the phonon flow propagating from the heated nanoisland. The resulting thermoEMF can have sufficient magnitudes to explain the low-voltage electron emission capability of nanoisland films of metals and sp2-bonded carbon, previously studied by our group. The phenomenon predicted by the model can be used in thermoelectric converters with untypical parameters or in systems for local cooling. [ABSTRACT FROM AUTHOR]

Abstract With buildings representing a substantial portion of global energy consumption, exploring alternatives to traditional fossil fuel-based heating and cooling systems is critical. Thermoelectricity offers a promising solution by converting temperature differentials into electrical voltage or vice versa, enabling efficient indoor thermal regulation. This paper presents a comprehensive investigation into the integration of thermoelectric wall systems for sustainable building climate control through numerical simulations and experimental analyses. Numerical simulations using computational fluid dynamics (CFD) techniques were conducted to model fluid flow and heat transfer within the thermoelectric wall systems under various operating conditions. These simulations provided insights into the system’s thermal behavior, which were validated through experimental setups designed to measure temperature differentials, airflow rates, and power consumption. The results showed that power consumption is directly correlated with electrical current, ranging from 0.19 W to 77.4 W as the current increased from 0.1 A to 2 A. Additionally, the heat absorbed by the system increased significantly with electrical current, by 706–1044%, depending on the air velocity. The thermal energy released from the hot side of the thermoelectric modules also rose substantially, ranging from 9850 to 5285% with increasing electrical current, and from 275 to 51% with higher air velocities. Moreover, increasing air velocity led to a 6.78–9.37% reduction in power consumption for currents between 0.1 A and 2 A. The coefficient of performance (COP) analysis revealed that optimizing both electrical current and air velocity is essential for maximizing system efficiency. While fan power consumption reduces COP at higher air velocities, neglecting fan power consumption results in COP improvements ranging from 6.5 × 10⁻⁴ to 49.0%. These findings highlight the potential of thermoelectric wall systems to enhance indoor comfort and energy efficiency in buildings.

[Display omitted] • Quaternary Ag 2 SbBiSe 4 NCs are synthesized by a colloidal synthesis route. • Ag 2 SbBiSe 4 has a cubic crystal structure and a wide band gap. • Ag 2 SbBiSe 4 maintains low lattice thermal conductivity of ca. 0.34 W m−1K−1. • Modulation doping through Sn NCs is used to tune the TE performance of Ag 2 SbBiSe 4. • A maximum ZT value of 0.64 at 760 K and a high Vickers Hardness of ~185 Hv are obtained. Materials with low intrinsic thermal conductivity are essential for the development of high-performance thermoelectric devices. At the same time, the solution processing of these materials may enable the cost-effective production of the devices. Herein, we detail a high-yield and scalable colloidal synthesis route to produce Ag 2 SbBiSe 4 nanocrystals (NCs) using amine-thiol-Se chemistry. The quaternary chalcogenide material is consolidated by a rapid hot-press maintaining the cubic crystalline structure. Transport measurements confirm that n -type Ag 2 SbBiSe 4 exhibits an inherently ultralow lattice thermal conductivity of ca. 0.34 W m−1K−1 at 760 K. Moreover, a modulation doping strategy based on the blending of semiconductor Ag 2 SbBiSe 4 and metallic Sn NCs is demonstrated to control the charge carrier concentration in the final composite material. The introduction of Sn nanodomains additionally blocks phonon propagation thus contributing to reducing the thermal conductivity of the final material. Ultimately, a peak thermoelectric figure of merit value of 0.64 at 760 K is achieved for n -type Ag 2 SbBiSe 4 -Sn nanocomposites that also demonstrate a notable Vickers hardness of 185 HV. [ABSTRACT FROM AUTHOR]

The energy transported by the electric current that circulates a thermoelectric element (TE) varies with position due to the Joule and Thomson effects. The Thomson effect may enhance or compensate the Joule effect. A method for measuring the Thomson coefficient of a TE is presented. This method is based on the total compensation of the Joule and Thomson effects. The electric current then flows without delivering power to the TE or absorbing power from it. For a TE, the global Thomson/Joule compensation ratio Φ ¯ T / J is defined as the ratio of the power absorbed by the current due to the Thomson effect and the power delivered by the current to the TE due to the Joule effect. It can be expressed as Φ ¯ T / J = I 0 / I , where I is the electric current and I 0 is the zero-power current, a quantity that is proportional to the average Thomson coefficient. When I = I 0 , the Thomson effect exactly compensates the Joule effect and the net power delivered by the current to the TE is zero. Since the power delivered by the current is related to the temperature distribution, temperature measurements for currents around I 0 can be used as the basis for a measurement technique of the Thomson coefficient. With varying current, the difference between the temperature at the center of the TE and the mean temperature between its extremes reverses its sign at the zero-power current, I = I 0 . This observation suggests the possibility of measuring the Thomson coefficient, but a quantitative analysis is needed. With calculations using the constant transport coefficients model for B i 2 T e 0.94 S e 0.06 3   and B i 0.25 S b 0.75 2 T e 3 , it is theoretically shown that a null temperature detector with a sensitivity of the order of 1 mK allows for the accurate determination of the Thomson coefficient. [ABSTRACT FROM AUTHOR]

This paper presents a novel waste-heat-powered, wireless, and battery-less Industrial Internet of Things (IIoT) device designed for predictive maintenance in Industry 4.0 environments. With a focus on real-time quality data, this device addresses the limitations of current battery-operated IIoT devices, such as energy consumption, transmission range, data rate, and constant quality of service. It is specifically developed for heat-intensive industries (e.g., iron and steel, cement, petrochemical, etc.), where self-heating nodes, low-power processing platforms, and industrial sensors align with the stringent requirements of industrial monitoring. The presented IIoT device uses thermoelectric generators based on the Seebeck effect to harness waste heat from any hot surface, such as pipes or chimneys, ensuring continuous power without the need for batteries. The energy that is recovered can be used to power devices using mid-range wireless protocols like Bluetooth 5.0, minimizing the need for extensive in-house wireless infrastructure and incorporating light-edge computing. Consequently, up to 98% of cloud computation efforts and associated greenhouse gas emissions are reduced as data is processed within the IoT device. From the environmental perspective, the deployment of such self-powered IIoT devices contributes to reducing the carbon footprint in energy-demanding industries, aiding their digitalization transition towards the industry 5.0 paradigm. This paper presents the results of the most challenging energy harvesting technologies based on an all-silicon micro thermoelectric generator with planar architecture. The effectiveness and self-powering ability of the selected model, coupled with an ultra-low-power processing platform and Bluetooth 5 connectivity, are validated in an equivalent industrial environment to monitor vibrations in an electric machine. This approach aligns with the EU's strategic objective of achieving net zero manufacturing capacity for renewable energy technologies, enhancing its position as a global leader in renewable energy technology (RET). [ABSTRACT FROM AUTHOR]

This work aims to develop a prototype for autonomously monitoring highway weather conditions using thermoelectric energy. The prototype utilizes solar thermal energy, heat absorbed by the asphalt and soil heat to generate, convert, manage, and store energy. The study investigates the optimal functioning of the thermoelectric generator, including utilizing the soil as a heat sink and incorporating passive thermal control devices like heat pipes. A commercial ultra-low power converter model LTC3108 was experimentally tested for efficient energy conversion. The monitoring system is designed to acquire readings from sensors measuring relevant climate parameters such as temperature, atmospheric pressure, and humidity, focusing on ultra-low power characteristics. The acquired data is transmitted via LoRa technology to a server for processing and analysis. The prototype generated 286.24 J of energy with a maximum temperature gradient of 4.25 ºC in the thermoelectric generator. The energy cost of transmitting a 40-byte message through the LoRaWAN module was 0.625 J. The proposed climate data acquisition circuit had a theoretical consumption of 17.69 J. Experimental tests with the LTC3108 converter, and a 0.22 F supercapacitor demonstrated successful data transmission. This work provides a solid foundation for future studies utilizing thermoelectric energy in highway applications, resulting in a prototype suitable for real-world road scenarios. [ABSTRACT FROM AUTHOR]

The stunning thermoelectric behavior of inorganic/organic hybrids and the lack of information on screen-printed flexible thermoelectric generators based on Cu 3 Se 2 and Polyaniline for low-temperature applications have motivated this work. The synergic influence of various acid dopants, concentration, and annealing temperature of polyaniline on the power density of Cu 3 Se 2 /PANI ink-based flexible thermoelectric generator is explored. The presence of 1.5 wt% of H 2 SO 4 -PANI, annealed at 60 °C, decreased the bandgap and electrical resistance of Cu 3 Se 2 by 11.96 % and 29.4 %, respectively. As a result, an increase of 46.06 % in the Seebeck coefficient and 242 % in the power output is achieved, which is many folds higher than the few reported works using novel materials. In addition, the Cu 3 Se 2 /H 2 SO 4 -PANI ink-based flexible thermoelectric generator with eight legs exhibited a maximum power output, power density, and power factor of 25.69 nW, 23.79 mW/m2, and 0.77 nW/m2K2 at ΔT = 100 °C, respectively under external load. [ABSTRACT FROM AUTHOR]

Using density functional theory combined with the first principles calculation method of non-equilibrium Green's function (NEGF-DFT), we studied the thermoelectric (TE) characteristics of one-dimensional γ-graphdiyne nanoribbons (γ-GDYNRs). The study found that the thermal conductivity of γ-GDYNRs has obvious anisotropy. At the same temperature and geometrical size, the lattice thermal conductivity of zigzag-edged γ-graphdiyne nanoribbons (γ-ZGDYNRs) is much lower than that of armchair-edged γ-graphdiyne nanoribbons (γ-AGDYNRs). We disclose the underlying mechanism for this intrinsic orientation. That is, γ-AGDYNRs have more phonon dispersion over the entire frequency range. Furthermore, the orientation dependence increases when the width of the γ-GDYNRs decreases. These excellent TE properties allow armchair-edged γ-graphdiyne nanoribbons with a planar width of 1.639 nm (γ-Z(2)GDYNRs) to have a higher power factor and lower thermal conductivity, ultimately resulting in a significantly higher TE conversion rate than other γ-GDYNR structures. [ABSTRACT FROM AUTHOR]

Understanding thermal transport at the submicron scale is crucial for engineering applications, especially in the thermal management of electronics and tailoring the thermal conductivity of thermoelectric materials. At the submicron scale, the macroscopic heat diffusion equation is no longer valid and the phonon Boltzmann transport equation (BTE) becomes the governing equation for thermal transport. However, previous thermal simulations based on the phonon BTE have two main limitations: relying on empirical parameters and prohibitive computational costs. Therefore, the phonon BTE is commonly used for qualitatively studying the non-Fourier thermal transport phenomena of toy problems. In this work, we demonstrate an ultra-efficient and parameter-free computational method of the phonon BTE to achieve quantitatively accurate thermal simulation for realistic materials and devices. By properly integrating the phonon properties from first-principles calculations, our method does not rely on empirical material properties input. It can be generally applicable for different materials and the predicted results can match well with experimental results. Moreover, by developing a suitable ensemble of advanced numerical algorithms, our method exhibits superior numerical efficiency. The full-scale (from ballistic to diffusive) thermal simulation of a 3-dimensional fin field-effect transistor with 13 million degrees of freedom, which is prohibitive for existing phonon BTE solvers even on supercomputers, can now be completed within two hours on a single personal computer. Our method makes it possible to achieve the predictive design of realistic nanostructures for the desired thermal conductivity. It also enables accurately resolving the temperature profiles at the transistor level, which helps in better understanding the self-heating effect of electronics. [ABSTRACT FROM AUTHOR]

This paper reports first-principles calculations on nanosheets of Ge–Sb–Te compounds, namely Sb 2 Te 3 , GeSb 2 Te 4 and Ge 2 Sb 2 Te 5 under two crystalline atomic stakings S1 and S2. Sb 2 Te 3 , GeSb 2 Te 4 and Ge 2 Sb 2 Te 5 -S1 are semiconductors with a narrow band gap ranging between 0.7 and 0.74 eV as evaluated with the HSEsol functional. The transport properties have been investigated by Boltzmann transport theory together with deformation potential theory. The strain effects on their electronic and thermoelectric properties as well as on their dynamical properties have been investigated. A valence band convergence is found in the equilibrium structures, which is an efficient approach to improve the thermoelectric performance of materials. Sb 2 Te 3 , GeSb 2 Te 4 and Ge 2 Sb 2 Te 5 -S1 possess high TE performance in a wide range of temperature, and the highest values of zT are 2.94, 2.63 and 2.27, respectively. [ABSTRACT FROM AUTHOR]

Abstract The integration of solar interfacial evaporation and power generation offers a sustainable solution to address water and electricity scarcity. Although water‐power cogeneration schemes are proposed, the existing schemes lack scalability, flexibility, convenience, and stability. These limitations severely limit their future industrial applications. In this study, we prepared a hybrid fabric composed of basalt fibers and cotton yarns with asymmetric structure using textile weaving technology. The cotton yarn in lower layer of fabric facilitates water transport, while the basalt fibers in upper layer enable thermal localization and water supply balancing. The carbon black is deposited on top layer by flame burning to facilitate photothermal conversion. The fabric exhibits a high evaporation rate of 1.52 kg m−2 h−1, which is 3.6 times that of pure water, and an efficiency of 88.06% under 1 kW m−2 light intensity. After assembly with a thermoelectric module, the hybrid system achieves a maximum output power density of 66.73 mW m−2. By exploiting the scalability of fabric, large‐scale desalination and power production can be achieved in outdoor environments. This study demonstrates the seamless integration of fabric‐based solar evaporation and waste heat‐to‐energy technologies, thereby providing new avenues for the development of scalable and stable water‐power cogeneration systems.

A comprehensive study of the thermoelectric properties of CuCr0.99Ln0.01S2 (Ln = La…Lu) disulfides was carried out in a temperature range of 300 to 740 K. The temperature dependencies of the Seebeck coefficient, electrical resistivity, and thermal conductivity were analyzed. It was found that the cationic substitution of chromium with lanthanides in the crystal structure of layered copper–chromium disulfide, CuCrS2 resulted in notable changes in the thermoelectric performance of CuCr0.99Ln0.01S2. The cationic substitution led to an increase in the Seebeck coefficient and electrical resistivity and a thermal conductivity decrease. The highest values of the thermoelectric figure of merit and power factor corresponded to the praseodymium-doped sample and an initial CuCrS2-matrix at 700–740 K. The cationic substitution with lanthanum, cerium, praseodymium, samarium, and terbium allowed for an enhancement of the thermoelectric performance of the initial matrix at a temperature range below 600 K. The cationic substitution of CuCrS2 with lanthanum and praseodymium ions appeared to be the most promising approach for increasing the thermoelectric performance of the initial matrix.

We present experimental evidence of a thermoelectric effect at the interface between two liquid metals. Using superimposed layers of mercury and gallium in a cylindrical vessel operating at room temperature, we provide a direct measurement of the electric current generated by the presence of a thermal gradient along a liquid-liquid interface. At the interface between two liquids, temperature gradients induced by thermal convection lead to a complex geometry of electric currents, ultimately generating current densities near boundaries that are significantly higher than those observed in conventional solid-state thermoelectricity. When a magnetic field is applied to the experiment, an azimuthal shear flow, exhibiting opposite circulation in each layer, is generated. Depending on the value of the magnetic field, two different flow regimes are identified, in good agreement with a model based on the spatial distribution of thermoelectric currents, which has no equivalent in solid systems. Finally, we discuss various applications of this effect, such as the efficiencyofliquid metal batteries. [ABSTRACT FROM AUTHOR]

A wearable energy harvester (EH) incorporating a face mask with a thermoelectric generator is demonstrated. The function of this device is to generate electrical power from the heat produced by the human body, particularly breath, with the specific aim of powering wearable sensor applications. A prototype was built using a commercially available N95 face mask, a thermoelectric generator, and a heatsink. The performance of this EH device was assessed using experimental and numerical methodologies. The experimentally tested power output of the prototype was found to be ≈100 µW, with a corresponding power density of ≈30 µW/cm3, for a temperature difference of 7°C. [ABSTRACT FROM AUTHOR]

Heat engines are key devices that convert thermal energy into usable energy. Strong thermoelectricity, at the basis of electrical heat engines, is present in superconducting spin tunnel barriers at cryogenic temperatures where conventional semiconducting or metallic technologies cease to work. Here we realize a superconducting spintronic heat engine consisting of a ferromagnetic insulator/superconductor/insulator/ferromagnet tunnel junction (EuS/Al/AlOx/Co). The efficiency of the engine is quantified for bath temperatures ranging from 25 mK up to 800 mK, and at different load resistances. Moreover, we show that the sign of the generated thermoelectric voltage can be inverted according to the parallel or anti-parallel orientation of the two ferromagnetic layers, EuS and Co. This realizes a thermoelectric spin valve controlling the sign and strength of the Seebeck coefficient, thereby implementing a thermoelectric memory cell. We propose a theoretical model that allows describing the experimental data and predicts the engine efficiency for different device parameters. An electrical heat engine has been realized at sub-Kelvin temperatures. It consists of a superconducting spin-selective tunnel junction of EuS/Al/AlOx/Co. The efficiency of the engine is quantified for different magnetic configurations. [ABSTRACT FROM AUTHOR]

A comprehensive study of the thermoelectric properties of CuCr0.99Ln0.01S2 (Ln = La...Lu) disulfides was carried out in a temperature range of 300 to 740 K. The temperature dependencies of the Seebeck coefficient, electrical resistivity, and thermal conductivity were analyzed. It was found that the cationic substitution of chromium with lanthanides in the crystal structure of layered copper–chromium disulfide, CuCrS2 resulted in notable changes in the thermoelectric performance of CuCr0.99Ln0.01S2. The cationic substitution led to an increase in the Seebeck coefficient and electrical resistivity and a thermal conductivity decrease. The highest values of the thermoelectric figure of merit and power factor corresponded to the praseodymium-doped sample and an initial CuCrS2-matrix at 700–740 K. The cationic substitution with lanthanum, cerium, praseodymium, samarium, and terbium allowed for an enhancement of the thermoelectric performance of the initial matrix at a temperature range below 600 K. The cationic substitution of CuCrS2 with lanthanum and praseodymium ions appeared to be the most promising approach for increasing the thermoelectric performance of the initial matrix. [ABSTRACT FROM AUTHOR]

The research and management of Industry 4.0 increasingly relies on accurate real-time quality data to apply efficient algorithms for predictive maintenance. Currently, Low-Power Wide-Area Networks (LPWANs) offer potential advantages in monitoring tasks for predictive maintenance. However, their applicability requires improvements in aspects such as energy consumption, transmission range, data rate and constant quality of service. Commonly used battery-operated IIoT devices have several limitations in their adoption in large facilities or heat-intensive industries (iron and steel, cement, etc.). In these cases, the self-heating nodes together with the appropriate low-power processing platform and industrial sensors are aligned with the requirements and real-time criteria required for industrial monitoring. From an environmental point of view, the carbon footprint associated with human activity leads to a steady rise in global average temperature. Most of the gases emitted into the atmosphere are due to these heat-intensive industries. In fact, much of the energy consumed by industries is dissipated in the form of waste heat. With this scenario, it makes sense to build heat transformation collection systems as guarantors of battery-free self-powered IIoT devices. Thermal energy harvesters work on the physical basis of the Seebeck effect. In this way, this paper gathers the methodology that standardizes the modelling and simulation of waste heat recovery systems for IoT nodes, gathering energy from any hot surface, such as a pipe or chimney. The statistical analysis is carried out with the data obtained from two different IoT architectures showing a good correlation between model simulation and prototype behaviour. Additionally, the selected model will be coupled to a low-power processing platform with LoRaWAN connectivity to demonstrate its effectiveness and self-powering ability in a real industrial environment. [ABSTRACT FROM AUTHOR]

The conversion of heat into electricity using the thermoelectric effect is a crucial issue to tackle the ever-increasing global energy consumption. Cu 2 Se is one of the high-performance thermoelectric materials due to its liquid-like atomic structure, which minimizes the phonon-derived thermal conductivity. Nevertheless, the unambiguous atomic structure of the low-temperature phase, α -Cu 2 Se, remains controversial. By employing a combination of theoretical approaches including an evolutionary algorithm for structural searching, density functional theory, and lattice dynamics, the α -Cu 2 Se phase is proposed to crystalize in the dynamically stable triclinic Cu 2 Se structure (s.g. P1) which can be regarded as a monoclinic polymorph (s.g. P2 1 /c †) through slight distortion. The corresponding heat capacity (C V) and Debye temperature (Θ D) are 0.37 J/g K and 276 K, respectively, indicating low thermal conductivity in the material. The semiconducting P1 phase possesses an indirect gap of 1.0 eV. Additionally, based on the Boltzmann transportation theory, fundamental thermoelectric parameters around the transition temperature (300–500 K) are investigated. Beyond the semiconducting phase, a novel metallic phase identified as the triclinic P 1 ̄ phase is also discovered, exhibiting a two-dimensional (2D) crystal geometry. [ABSTRACT FROM AUTHOR]

The development of two-dimensional (2D) materials has received wide attention as a generation of optoelectronics, thermoelectric, and other applications. In this study, a novel 2D material, PbN, is proposed as an elemental method using the prototype of a recent reported nitride (J. Phys. Chem. C 2023, 127, 43, 21,006-21014). Based on first-principle calculations, the PbN monolayer is investigated as stable at 900 K, and the isotropic mechanical behavior is addressed by the Young's modulus and Poisson's ratio at 67.4 N m-1 and 0.15, respectively. The PbN monolayer also presents excellent catalytic performance with Gibbs free energy of 0.41 eV. Zero bandgap is found for the PbN monolayer, and it can be opened at about 0.128 eV by forming a heterostructure with CdO. Furthermore, the PbN/CdO is constructed by Van der Waals interaction, while the apparent potential drop and charge transfer are investigated at the interface. The PbN/CdO heterostructure also possesses excellent light absorption properties. The results provide theoretical guidance for the design of layered functional materials. [ABSTRACT FROM AUTHOR]

ZnO is one of the most promising mid-high temperature thermoelectric materials because of low cost, easy preparation and favorable chemical stability. Herein, the influence mechanism of Alkaline earth metal Ba doping on the thermoelectric properties of ZnO was studied. It is found that Ba doping can effectively improve the carrier mobility and electrical conductivity for that Ba doping can shorten the Zn–O bond and enhance the overlap and hybridization of electron orbitals. The electronic density of states of Zn and O is significantly enhanced. The highest power factor of ∼7.95 μWcm−1K−2 was obtained at 873 K, which is ∼1.4 times higher than that of the undoped sample. Due to the decrease of Young's modulus caused by Ba doping and the enhancement of phonon scattering of heavy element, the thermal conductivity decreases obviously in the whole temperature range. Ba doping enhanced the effect of phonon glass-electron crystal, and the ZT value of ∼0.345 was obtained at 873 K, which is ∼3.52 times as that of the pristine ZnO. The results indicated that alkaline earth metal doping is an effective way to improve the thermoelectric properties of ZnO functional materials. [ABSTRACT FROM AUTHOR]

This paper develops a thermoelectric (TE)–piezoelectric (PE) hybrid structure with the PE layer acting as both a support membrane and a sensor for the TE film for microelectronics applications. The TE and PE layers are assumed to be perfectly bonded mechanically and thermally but electrically shielded and insulated with each other. The thermo-electro-mechanical responses of the hybrid bilayer under the TE generator operation conditions are obtained, and the influence of the PE layer on the TE energy conversion efficiency is investigated. The numerical results for a Bi2Te3/PZT-5H bilayer structure show that large compressive stresses develop in both the PE and TE layers. With a decrease in the PE layer thickness, the magnitude of the maximum compressive stress in the PE layer increases whereas the maximum magnitude of the stress in the TE layer decreases. The numerical result of the TE energy conversion efficiency shows that increasing the PE layer thickness leads to lower energy conversion efficiencies. A nearly 40% reduction in the peak efficiency is observed with a PE layer of the same thickness as that of the TE layer. These results suggest that design of TE films with supporting/sensing membranes must consider both aspects of energy conversion efficiency and the thermomechanical reliability of both the TE and PE layers. [ABSTRACT FROM AUTHOR]

Thermoelectric materials have drawn much attention over the last two decades due to the increase in global energy demand. However, designing efficient thermoelectrics reveals itself as a tough task for their properties (Seebeck coefficient, electrical conductivity, thermal conductivity) are mutually opposed. Hence, most recently, new design approaches have appeared, among which high-throughput methods have been implemented either experimentally or computationally. In this work, a high-throughput computer program has been designed to generate over 4000 structures based on a small set of complex layered chalcogenide compounds taken from the mAIVBVI nA2VB3VI homologous series, where AIV is Ge, AV is Sb and BVI is Te. The computer-generated structures have been investigated using density-functional theory methods, and the electronic and transport properties have been calculated. It has been found, using the quantum theory of atoms in molecules and crystals, that a wide variety of bond types constitutes the bonding network of the structures. All the structures are found to have negative formation energies. Among the obtained final structures, 43 are found with a wide band gap energy (>0.25 eV), 358 with semi-conductor/metal characteristics, and 731 with metallic characteristics. The transport properties calculations, using the Boltzmann equation, reveal that two p-type and 86 n-type structures are potentially promising compounds for thermoelectric applications. [ABSTRACT FROM AUTHOR]

The application of nanotechnology in developing novel thermoelectric materials has yielded remarkable advancements in material efficiency. In many instances, dimensional constraints have resulted in a beneficial decoupling of thermal conductivity and power factor, leading to large increases in the achievable thermoelectric figure of merit ( Z T ). For instance, the Z T of silicon increases by nearly two orders of magnitude when transitioning from bulk single crystals to nanowires. Metal-assisted chemical etching offers a viable, low-cost route for preparing silicon nanopillars for use in thermoelectric devices. The aim of this paper is to review strategies for obtaining high-density forests of Si nanopillars and achieving high-quality contacts on them. We will discuss how electroplating can be used for this aim. As an alternative, nanopillars can be embedded into appropriate electrical and thermal insulators, with contacts made by metal evaporation on uncapped nanopillar tips. In both cases, it will be shown how achieving control over surface termination and defectivity is of paramount importance, demonstrating how a judicious control of defectivity enhances contact quality. [ABSTRACT FROM AUTHOR]

The temperature dependences of the thermoelectromotive force of chromium mono and disilicides in the temperature range 200℃÷+600℃ have been studied. For chromium disilicide, the dependence of the thermopower coefficient (α) on temperature (T) has three sections. Chromium monosilicide is characterized by a smooth increase in thermopower with increasing temperatures up to 200℃, and then its constancy. It was revealed that silicides rich in chromium atoms have lower thermopower values than silicides rich in silicon. The maximum thermo-EMF values of 110 μV/K and 190 μV/K were observed for chromium mono- and disilicides, respectively. It was revealed that for chromium silicides the dependence of the dimensionless parameter Q = Z∙T on temperature is linear. The possibility of predicting the technology of synthesis of semiconductor material with optimal thermoelectric properties using the dependence of thermopower on conductivity and the parameter Q on temperature is shown. [ABSTRACT FROM AUTHOR]

It is extremely important for the performance and success of the system to know the cooling or heating surfaces of the thermoelectric modules (TEMs) as cooler or generator, according to the heat transfer direction, and to carry out their installation correctly, taking this into account. In TEMs, the direction of heat transfer between surfaces changes depending on the applied DC direction, and while one surface of the module cools, the other heats up. In this respect, the state of the positive and negative poles in the design and production of TEMs directly affects the heat transfer direction between the module surfaces. On the other hand, the contact direction of the surfaces of the TEMs used in a designed thermoelectric system (TES) is of great importance in order to perform the heat transfer correctly without loss of performance. In this study, a system is designed to detect the heat transfer direction of TEMs using image processing techniques. The basic principle of the system is to determine the positive and negative poles of the TEMs together with the ceramic plate, using the color-based image processing method, and to determine the heat transfer direction by utilizing their relative positions. With the designed system, the heat transfer direction of TEMs at different illuminance levels is tried to be determined and successful results were obtained. As a result, it is thought that the developed system will contribute to the automatic error control for the production and assembly of TEMs. [ABSTRACT FROM AUTHOR]

Bismuth telluride, a highly efficient thermoelectric material, stands out for applications around room temperature in wearable devices. By harnessing the thermal gradient established between the human body and ambient temperature, we can generate useable electricity. Notably, bismuth telluride nanostructures exhibit significantly lower thermal conductivities compared to their bulk counterparts. As a result, the thermoelectric efficiency achieved is notably higher. Our research focuses on developing efficient nanostructured materials based on bismuth telluride inside a flexible substrate made of polyester. We employ scalable methods, such as template-assisted electrochemical deposition, to fabricate these nanostructures. In this study, we present an approach to the development of flexible nanostructured thermoelectric materials. Despite using a reduced quantity of active material, our electrochemically deposited nanostructures inside a flexible template demonstrate a remarkable performance. They exhibit 24 % of the Power Factor reported for conventional electrochemically fabricated Bi2Te3 thin films, and notably, they even surpass the Power Factor reported for flexible Bi2Te3-based inks used in the creation of flexible generators. This achievement underscores the potential of our method in the advancement of efficient, flexible thermoelectric devices.

The possible contribution of phonon drag effect to the thermoelectrically sustained potential of a heated nanoisland on a semiconductor surface was estimated in a first principal consideration. We regarded electrons and phonons as interacting particles, and the interaction cross-section was derived from the basic theory of semiconductors. The solution of the equation of motion for average electrons under the simultaneous action of phonon drag and electric field gave the distributions of phonon flux, density of charge carriers and electric potential. Dimensional suppression of thermal conductance and electron-phonon interaction were accounted for but found to be less effective than expected. The developed model predicts the formation of a layer with a high density of charge carriers that is practically independent of the concentration of dopant ions. This layer can effectively intercept the phonon flow propagating from the heated nanoisland. The resulting thermoEMF can have sufficient magnitudes to explain the low-voltage electron emission capability of nanoisland films of metals and sp2-bonded carbon, previously studied by our group. The phenomenon predicted by the model can be used in thermoelectric converters with untypical parameters or in systems for local cooling.

High energy‐conversion efficiency (ZT) of thermoelectric materials has been achieved in heavy metal chalcogenides, but the use of toxic Pb or Te is an obstacle for wide applications of thermoelectricity. Here, high ZT is demonstrated in toxic‐element free Ba3BO (B = Si and Ge) with inverse‐perovskite structure. The negatively charged B ion contributes to hole transport with long carrier life time, and their highly dispersive bands with multiple valley degeneracy realize both high p‐type electronic conductivity and high Seebeck coefficient, resulting in high power factor (PF). In addition, extremely low lattice thermal conductivities (κlat) 1.0–0.4 W m−1 K−1 at T = 300–600 K are observed in Ba3BO. Highly distorted O–Ba6 octahedral framework with weak ionic bonds between Ba with large mass and O provides low phonon velocities and strong phonon scattering in Ba3BO. As a consequence of high PF and low κlat, Ba3SiO (Ba3GeO) exhibits rather high ZT = 0.16–0.84 (0.35–0.65) at T = 300–623 K (300–523 K). Finally, based on first‐principles carrier and phonon transport calculations, maximum ZT is predicted to be 2.14 for Ba3SiO and 1.21 for Ba3GeO at T = 600 K by optimizing hole concentration. Present results propose that inverse‐perovskites would be a new platform of environmentally‐benign high‐ZT thermoelectric materials. [ABSTRACT FROM AUTHOR]

This paper presents an innovative approach to the integration of thermoelectric microgenerators (μTEGs) based on thick-film thermopiles of planar constantan–silver (CuNi-Ag) and calcium cobaltite oxide–silver (Ca3Co4O9-Ag) thick-film thermopiles with radio frequency identification (RFID) technology. The goal was to consider using the TEG for an active or semi-passive RFID tag. The proposed implementation would allow the communication distance to be increased or even operated without changing batteries. This article discusses the principles of planar thermoelectric microgenerators (μTEGs), focusing on their ability to convert the temperature difference into electrical energy. The concept of integration with active or semi-passive tags is presented, as well as the results of energy efficiency tests, considering various environmental conditions. On the basis of the measurements, the parameters of thermopiles consisting of more thermocouples were simulated to provide the required voltage and power for cooperation with RFID tags. The conclusions of the research indicate promising prospects for the integration of planar thermoelectric microgenerators with RFID technology, opening the way to more sustainable and efficient monitoring and identification systems. Our work provides the theoretical basis and practical experimental data for the further development and implementation of this innovative technology. [ABSTRACT FROM AUTHOR]

Layered van der Waals (vdw) materials have been proposed as light-absorbing materials for photovoltaic applications. InSe is a layered vdw semiconductor with ultra-high carrier mobility, strong charge transfer ability, super deformability, thermoelectricity, and optoelectronic properties. Its γ phase, or γ-InSe, was greatly stabilized by doping recently, which also exhibits sliding ferroelectricity. In this study, we propose that γ-phase InSe (γ-InSe), which was recently synthesized in a high-quality bulk phase, could be an excellent light-absorbing material candidate. Based on the first-principles simulations, bulk γ-InSe is found to possess suitable bandgap, decent absorption, and low effective mass. The investigation of defect properties reveals the major defect types, defect levels, and deep-level defects that could possibly harm the efficiency, and the deep-level defects can be significantly suppressed under Se-rich conditions. In addition, γ-InSe is intrinsically n-type, which can be tuned into weak p-type by Zn and Cd doping. We also identify the defect types of Y and Bi doping, which have been experimentally used to adjust the mechanical property of γ-InSe, and find that Y interstices could play an important role in improving the stiffness of γ-InSe. Our study provides theoretical insights for photovoltaic and other photoelectronic applications based on this interesting ferroelectric layered vdw material. [ABSTRACT FROM AUTHOR]

We consider an autonomous heat engine in simultaneous contact with a hot and a cold reservoir and describe it within a linear irreversible framework. In a tight-coupling approximation, the rate of entropy generation is effectively written in terms of a single thermal flux that is a homogeneous function of the hot and cold fluxes. The specific algebraic forms of the effective flux are deduced for scenarios containing internal and external irreversibilities for the typical example of a thermoelectric generator. [ABSTRACT FROM AUTHOR]

The Kelvin relation, relating the Seebeck coefficient and the Peltier coefficient, is a theoretical basis of thermoelectricity. It was first derived by Kelvin using a quasi-thermodynamic approach. However, Kelvin's approach was subjected to much criticism due to the rude neglect of irreversible factors. It was only later that a seemingly plausible proof of the Kelvin relation was given using the Onsager reciprocal relation with full consideration of irreversibility. Despite this, a critical issue remains. It is believed that the Seebeck and Peltier effects are thermodynamically reversible, and therefore, the Kelvin relation should also be independent of irreversibility. Kelvin's quasi-thermodynamic approach, although seemingly irrational, may well have touched on the essence of thermoelectricity. To avoid Kelvin's dilemma, this study conceives the physical scenarios of equilibrium thermodynamics to explore thermoelectricity. Unlike Kelvin's quasi-thermodynamic approach, here, a completely reversible thermodynamic approach is used to establish the reciprocal relations of thermoelectricity, on the basis of which the Kelvin relation is once again derived. Moreover, a direct thermodynamic derivation of the Onsager reciprocal relations for fluxes defined as the time derivative of an extensive state variable is given using the method of equilibrium thermodynamics. The present theory can be extended to other coupled phenomena. [ABSTRACT FROM AUTHOR]

This paper focuses on modelling of Heat sink for thermoelectric Generator which requires a heat sink to achieve high electrical output efficiency. Thermoelectricity refers to a phenomenon in which a temperature gradient causes a flux of the electric charge. This work deals with models of different geometries, based on heatsinks designed to improve thermoelectric generator performance. The thermo-electric generator efficiency increased with the temperature gradient ΔT with the cooling junction. Here comparing of the conventional and analytical heat sinks, from analytical heat sinks, we can choose the beat efficient heat sink for thermoelectric generator high performance. The heat sink, whose device is to be improved by the geometry of the Heat sink models designed with different shapes of Fins, provides this cooling junction. After analyzing the various heat sink models, with different geometrical Heat sink fins, cylindrical-shaped fins's-height at 10 mm temperature cooled to 6.7℃ and pressure loss to 1.8Pa from high temperature were found to be most effective for thermoelectric generator efficiency. The improvement in temperature and pressure loss was achieved using the optimized cylindrical heat sink with 10mm fins height design. [ABSTRACT FROM AUTHOR]

Inherently poor lattice thermal conductivity (⁠ κ L ⁠) is highly desired for applications like thermoelectricity, thermal management in electronics, thermal barrier coatings and refractories. Recently, complex crystalline materials have drawn serious scientific attention because of various interesting underlying physical phenomena which explain the unique thermal properties. In this review, we have discussed various interesting concepts and their consequences leading to ultralow κ L in complex bulk chalcogenide minerals having multiple scattering channels for heat-carrying phonons. The primary focus of this review is on the Ag- and Cu-based large unit cell structures with low heat capacity and liquid-like superionic conduction of cations. The Ag/Cu sublattice of these materials that followed the phonon-liquid electron-crystal concept strongly reduces the transportation of phonons and enhances the scattering process. The presence of a large number of atoms in the unit cell results in low acoustic phonons cut-off frequency, robust acoustic–optical phonons scattering, poor sound velocity and strong crystal anharmonicity inside the crystalline lattice. [ABSTRACT FROM AUTHOR]

We report on the successful synthesis of Bi1−xSbx alloys via mechanical alloying followed by sintering via spark plasma sintering, and the study of their lattice dynamics by Raman spectroscopy as well as their transport and thermoelectric properties. We observed an upshift of the frequency of the Raman-active Eg vibrational mode with increasing Sb content but no significant change for the frequency of the Raman-active A1g vibrational mode. Conversely, the linewidth of the Eg vibrational mode did not change significantly with increasing Sb content, whereas a twofold increase was observed for the A1g vibrational mode. Moreover, we confirm the emergence of several new vibrational modes with Sb alloying that could be associated with Bi-Sb and Sb-Sb vibrations. Rather large magnetoresistance was observed for all samples at room temperature. From the Seebeck coefficients, we determined the energy bandgaps in our samples, which are larger than those in bulk compounds, presumably due to the electronic confinement effect. We report a rather large thermoelectric power factor of 2–3 mW/m.K2 and thermoelectric figure of merit ZT of 0.15–0.23 at room temperature. However, ZT values were not improved at room temperature compared to prior works because of the rather large thermal conductivity of 3.75–4.5 W/m.K at room temperature. We find a larger resistivity, Seebeck coefficient, and power factor for the samples sintered at 200 °C for 5 min than for the samples sintered at 220 °C for 15 min, but similar thermal conductivity, resulting in larger ZT for the samples obtained in the first conditions. The samples with low Sb content x = 0.05 have a lower power factor and larger thermal conductivity than the samples with x = 0.12 and x = 0.15 for the same sintering conditions, which results in lower ZT for x = 0.05. [ABSTRACT FROM AUTHOR]

Abstract We report a comprehensive study of the nanoscale inhomogeneity and disorder on the thermoelectric properties of FeSe $$_{1-x}$$ 1 - x S $$_x$$ x ( $$0 \le x \le 1$$ 0 ≤ x ≤ 1 ) single crystals and the evolution of correlation strength with S substitution. A hump-like feature in temperature-dependent thermpower is enhanced for x = 0.12 and 0.14 in the nematic region with increasing in orbital-selective electronic correlations, which is strongly suppressed across the nematic critical point and for higher S content. Nanoscale Se/S atom disorder in the tetrahedral surroundings of Fe atoms is confirmed by scanning transmission electron microscopy measurements, providing an insight into the nanostructural details and the evolution of correlation strength in FeSe $$_{1-x}$$ 1 - x S $$_x$$ x .

Abstract Thermoelectric materials have an important role in electronic chips due to their capability of heat and electricity interconversion. Here we investigated thermoelectric properties of Zn3As2 and ZnSb by using density functional theory combined with the Boltzmann transport equation. We evaluated the well‐known thermoelectric figure of merit (ZT) of both materials and found a maximum ZT of 0.09 and 0.27 for Zn3As2 and ZnSb at 200°C and 1000°C, respectively. While investigating the electronic properties, we found that Zn3As2 has a direct band‐gap at the Γ‐point of 1.01 eV, while ZnSb has an indirect bandgap of 0.65 eV. Both materials exhibited high optical absorption and reflectivity in the visible and UV regions, which suggest that these materials are beneficial in photovoltaic cells, along with thermoelectric applications.

This paper presents a novel waste-heat-powered, wireless, and battery-less Industrial Internet of Things (IIoT) device designed for predictive maintenance in Industry 4.0 environments. With a focus on real-time quality data, this device addresses the limitations of current battery-operated IIoT devices, such as energy consumption, transmission range, data rate, and constant quality of service. It is specifically developed for heat-intensive industries (e.g., iron and steel, cement, petrochemical, etc.), where self-heating nodes, low-power processing platforms, and industrial sensors align with the stringent requirements of industrial monitoring. The presented IIoT device uses thermoelectric generators based on the Seebeck effect to harness waste heat from any hot surface, such as pipes or chimneys, ensuring continuous power without the need for batteries. The energy that is recovered can be used to power devices using mid-range wireless protocols like Bluetooth 5.0, minimizing the need for extensive in-house wireless infrastructure and incorporating light-edge computing. Consequently, up to 98% of cloud computation efforts and associated greenhouse gas emissions are reduced as data is processed within the IoT device. From the environmental perspective, the deployment of such self-powered IIoT devices contributes to reducing the carbon footprint in energy-demanding industries, aiding their digitalization transition towards the industry 5.0 paradigm. This paper presents the results of the most challenging energy harvesting technologies based on an all-silicon micro thermoelectric generator with planar architecture. The effectiveness and self-powering ability of the selected model, coupled with an ultra-low-power processing platform and Bluetooth 5 connectivity, are validated in an equivalent industrial environment to monitor vibrations in an electric machine. This approach aligns with the EU’s strategic objective of achieving net zero manufacturing capacity for renewable energy technologies, enhancing its position as a global leader in renewable energy technology (RET).

Using density functional theory combined with the first principles calculation method of non-equilibrium Green’s function (NEGF-DFT), we studied the thermoelectric (TE) characteristics of one-dimensional γ-graphdiyne nanoribbons (γ-GDYNRs). The study found that the thermal conductivity of γ-GDYNRs has obvious anisotropy. At the same temperature and geometrical size, the lattice thermal conductivity of zigzag-edged γ-graphdiyne nanoribbons (γ-ZGDYNRs) is much lower than that of armchair-edged γ-graphdiyne nanoribbons (γ-AGDYNRs). We disclose the underlying mechanism for this intrinsic orientation. That is, γ-AGDYNRs have more phonon dispersion over the entire frequency range. Furthermore, the orientation dependence increases when the width of the γ-GDYNRs decreases. These excellent TE properties allow armchair-edged γ-graphdiyne nanoribbons with a planar width of 1.639 nm (γ-Z(2)GDYNRs) to have a higher power factor and lower thermal conductivity, ultimately resulting in a significantly higher TE conversion rate than other γ-GDYNR structures.

This study analyzes and examines the Earth-Air Thermoelectricity Generator (TTEJ), which works with earth temperature and is recommended to be used peculiarly in safety systems, both theoretically and experientially. To examine how TTEJ functions in natural conditions, temperatures at the soil depth and soil surface were equal to the length of the generator, and ΔT temperature differences were measured and modeled throughout four seasons in five different precincts in Ankara. To create the environment to measure and analyze how TTEJ functions in natural conditions, in addition to the standard TEJ theory, to design a thermoelectric earth-air generator or to calculate its parameters, a mathematical model of TTEJ is created by embodying both thermic processes and the thermoelectric generator that functions conveniently for these processes. The thermoelectric parameters such as power P(W) produced by the generator based on T, resistance U(V), and current I(A) are calculated using a custom experiment mechanism built specifically for this research, and the results are compared to theoretical results. The outcome of theoretical and experimental results is congruence. The custom earth-air generator that is created as a model implementation can provide a reliable safety system that is presented and detected. Thus, it is concluded that without any requirements for an electricity cable, it is possible to create a system that can work via TTEJ by generating electricity with the help of the earth's temperature in the event of a property violation or other security-related issue and notifying the security units. Also, it is predicted that, as an innovative and environment-friendly product, TTEJ will be used in various fields of work, especially in military applications.

Based on a thermodynamic ratio between the thermopower coefficient and entropy of the electrically conducting medium, we obtained an estimated value of the thermoelectric efficiency parameter ZT for an electronic system of fully ionised plasma. An example of such a system, which is in the most disordered state, is the electron-nuclear plasma of the Sun. The resulting universal value ZT = (25/6) can be considered as an assessment of the limiting capabilities of thermoelectric energy conversion.