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The electro-thermal performance of silicon nanosheet field-effect transistors (NSFETs) with various parasitic bottom transistor (trpbt)-controlling schemes is evaluated. Conventional punch-through stopper, trench inner-spacer (TIS), and bottom oxide (BOX) schemes were investigated from single-device to circuit-level evaluations to avoid overestimating heat's impact on performance. For single-device evaluations, the TIS scheme maintains the device temperature 59.6 and 50.4 K lower than the BOX scheme for n/pFETs, respectively, due to the low thermal conductivity of BOX. However, when the over-etched S/D recess depth (TSD) exceeds 2 nm in the TIS scheme, the RC delay becomes larger than that of the BOX scheme due to increased gate capacitance (Cgg) as the TSD increases. A higher TIS height prevents the Cgg increase and exhibits the best electro-thermal performance at single-device operation. Circuit-level evaluations are conducted with ring oscillators using 3D mixed-mode simulation. Although TIS and BOX schemes have similar oscillation frequencies, the TIS scheme has a slightly lower device temperature. This thermal superiority of the TIS scheme becomes more pronounced as the load capacitance (CL) increases. As CL increases from 1 to 10 fF, the temperature difference between TIS and BOX schemes widens from 1.5 to 4.8 K. Therefore, the TIS scheme is most suitable for controlling trpbt and improving electro-thermal performance in sub-3 nm node NSFETs. [ABSTRACT FROM AUTHOR]

Carbon fibers exhibit good electrothermal performance; however, they break easily during the weaving process. This study used a facile computerized embroidery process to design and fabricate carbon fibers with controllable and precise patterned structures. The obtained carbon fiber/cement composites (CFCs) exhibited excellent electrothermal performance (100 ℃ under 30 V), low energy consumption (400 mW/℃), and homogeneous heat distribution with a unique heating element (carbon fibers) structure. The difference between the maximum and average surface temperatures improved, and the surface heat distributions of the CFCs under different structures were determined using a finite element simulation. CFCs with different complex heat element structures were successfully fabricated, and the mechanism regulating the heat distribution of the CFCs was revealed. Embroidery technology provides a novel strategy for the fabrication of carbon fiber/cement composite materials with a controllable carbon fiber structure, thereby significantly broadening the application of cement composites for electrothermal applications.

The electro-thermal performance of silicon nanosheet field-effect transistors (NSFETs) with various parasitic bottom transistor (trpbt)-controlling schemes is evaluated. Conventional punch-through stopper, trench inner-spacer (TIS), and bottom oxide (BOX) schemes were investigated from single-device to circuit-level evaluations to avoid overestimating heat’s impact on performance. For single-device evaluations, the TIS scheme maintains the device temperature 59.6 and 50.4 K lower than the BOX scheme for n/pFETs, respectively, due to the low thermal conductivity of BOX. However, when the over-etched S/D recess depth (TSD) exceeds 2 nm in the TIS scheme, the RC delay becomes larger than that of the BOX scheme due to increased gate capacitance (Cgg) as the TSD increases. A higher TIS height prevents the Cgg increase and exhibits the best electro-thermal performance at single-device operation. Circuit-level evaluations are conducted with ring oscillators using 3D mixed-mode simulation. Although TIS and BOX schemes have similar oscillation frequencies, the TIS scheme has a slightly lower device temperature. This thermal superiority of the TIS scheme becomes more pronounced as the load capacitance (CL) increases. As CL increases from 1 to 10 fF, the temperature difference between TIS and BOX schemes widens from 1.5 to 4.8 K. Therefore, the TIS scheme is most suitable for controlling trpbt and improving electro-thermal performance in sub-3 nm node NSFETs.

A conductive ceramic composite (CCC) based on carbonized phenolic resin is fabricated via a facile and scalable dry-pressing method. A conductive carbonaceous precursor solution is homogeneously mixed with a ceramic precursor. Subsequently, carbonization and ceramicization are achieved simultaneously in a single heating process. The carbonized materials endow the composites with excellent electrical conductivity and reliable cyclic heating properties. The temperature of the obtained composites is approximately 386 °C at 12 V after 10 min and 400 °C at 20 V after 48 s, and their energy consumption is low. Thermal images show that an even heat distribution is achieved on the composite surface, and that the electro-thermal performance can be adjusted by changing the electrical circuit arrangement (series or parallel circuits). In addition, the ceramic composites exhibit favorable electromagnetic interference (EMI) shielding performance of 26.2 dB at 8.2 GHz and improved photothermal conversion effect compared with the pristine ceramic. More importantly, this single-step heating provides a convenient and cost-effective approach for producing CCCs, thereby enabling the scalable production of conductive ceramics for electro-thermal applications. The excellent electrical performance facilitates the application of ceramic composites in Joule heating (e.g., deicing, boiling water, and cooking) and EMI shielding.

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[Display omitted] • The carbon fiber/cement composite (CFC) was fabricated with braided carbon fiber. • The carbon fiber presents with controllable and precise patterned structures via a facile embroidery process. • The CFC exhibits electrothermal performance, low energy consumption (and homogeneous heat distribution. • The difference between the maximum and average surface temperatures was systematically investigated and improved. Carbon fibers exhibit good electrothermal performance; however, they break easily during the weaving process. This study used a facile computerized embroidery process to design and fabricate carbon fibers with controllable and precise patterned structures. The obtained carbon fiber/cement composites (CFCs) exhibited excellent electrothermal performance (100 ℃ under 30 V), low energy consumption (400 mW/℃), and homogeneous heat distribution with a unique heating element (carbon fibers) structure. The difference between the maximum and average surface temperatures improved, and the surface heat distributions of the CFCs under different structures were determined using a finite element simulation. CFCs with different complex heat element structures were successfully fabricated, and the mechanism regulating the heat distribution of the CFCs was revealed. Embroidery technology provides a novel strategy for the fabrication of carbon fiber/cement composite materials with a controllable carbon fiber structure, thereby significantly broadening the application of cement composites for electrothermal applications. [ABSTRACT FROM AUTHOR]

Electro‐thermal phase‐change materials (PCMs) enable continuous operation of heating‐related processes, which is urgently required for modern thermal‐management devices. Driven by the unmet needs to develop promising electro‐thermal PCMs with low operation voltage and high electro‐thermal storage efficiency simultaneously, unique ZIF@MOF‐derived carbon‐nanotube (CNT)‐penetrated porous carbon supports for electro‐thermal PCMs are introduced. The network structure of the support decreases the resistivity of the composite and ensures a low operation voltage. Furthermore, abundant CNT cores in porous carbon shells facilitate interfacial interaction between the PCMs and the support and realize a rapid heat transformation. It is noted that low thermal conductive porous carbon shells prevent convective heat dissipation at the CNT‐air interface to a great degree which leads to enhanced electro‐thermal storage efficiency. Consequently, the obtained electro‐thermal PCMs exhibit a low operation voltage of 1.1 V and a record‐high electro‐thermal storage efficiency of 94.5%, which shows great potential in thermal management of electronic devices. [ABSTRACT FROM AUTHOR]

The electrical and thermal characteristics of Li-ion batteries (LIBs) are closely related and need to be further investigated. Especially for the promising immersion cooling LIBs, the interaction between battery performance and immersion thermal management system still needs to be clearly illustrated. This research aims to reveal the electro-thermal equalization behaviors of LIB modules with immersion cooling. An electro-thermal test platform was established for a series-connected LIB module. Besides the experimental research on the thermal control capability, the electro-thermal equalization behaviors of the LIB module with different cooling methods are also investigated at steady and dynamic operations. Results show that the electrical inconsistency between the LIBs with different cooling schemes intensifies at the end of discharge, and the voltage deviation (δ U,t) increases quickly at high rates. However, immersion cooling can mitigate this behavior effectively. As the immersion height ratio varies from 0 to 1, the δ U,t at the end of the 2C discharge declines from 17.1% to 4.3%, then rises to 7.9%. From a general viewpoint, the indicators, including the equalization rates of the voltage, average temperature, and temperature difference, are defined further to assess the electro-thermal equalization behaviors of the module. According to the estimation, the equalization capacities are static flow > forced flow > air cooling for all indicators. Static flow immersion cooling demonstrates superiority in thermal and electrical equalization, while forced flow immersion cooling is still necessary at high discharge rates for reducing thermal recovery time and temperature rise. [Display omitted] • Battery immersion cooling test was developed for electro-thermal performance. • Immersion cooling mitigates the aggravation of voltage deviation of batteries. • Effect of immersion heights on electro-thermal equalization behavior was discussed. • The equalization rates are proposed to assess equilibrium ability. • The equalization behavior of module shows static flow > forced flow > air cooling. [ABSTRACT FROM AUTHOR]

In this work, a personal thermal management (PTM) device based on single walled carbon nanotubes (SWCNTs) functionalized polyester fabrics had been studied. Polyester fabrics were functionalized with SWCNTs through coating method with poly (butyl acrylate) emulsion as the adhesive. The SEM images exhibited that SWCNTs formed high-efficiently conductive networks due to the large aspect ratio and uniform dispersion. A steady-state temperature of 40 °C was achieved at the input voltage of 2.5 V within 7 s, which exhibited excellent electro-thermal performance. Even under periodic heating-cooling conditions, heating system still displayed relatively stable temperature and relative resistance, which could have potential application for wearable clothes.

In this study, a single firing was used to convert stabilized polyacrylonitrile (PAN) fibers and ceramic forming materials (kaolin, feldspar, and quartz) into carbon fiber/ceramic composites. For the first time, PAN carbonization and ceramic sintering were achieved simultaneously in one thermal cycle and the microscopic morphologies and physical features of the obtained carbon fiber/ceramic composites were characterized in detail. The obtained carbon fiber/ceramic composite showed comparable flexural strength as commercial ceramic tiles. Meanwhile, the composite showed exceptional electro-thermal performance based on the electro-thermal performance of the carbonized PAN fibers, which could reach 108 ℃ after 15 s, 204 ℃ after 90 s, and 292 ℃ after 450 s at 5 V (2.6 A), thereby making the ceramic composite a good candidate as an indoor climate control heater, defogger device, kettle, and other heating element. [ABSTRACT FROM AUTHOR]

Electro-thermal applications of cement composites are restricted by their poor conductivity. This study expands the homogeneously distributed graphite inside the matrix via a facile heat treatment process to form new conductive networks, thus endowing the cement composites with excellent conductivity. The obtained cement composites exhibit excellent electro-thermal performance and reliable cyclic heating properties. The average surface temperature of the composite is approximately 417 °C under 20 V, with uniform heat distribution. The surface temperature of the composites can be controlled by the expanded graphite content and applied voltage. Furthermore, the obtained cement composite melts 150 g ice cubes in 12 min under 12 V, thus exhibiting excellent deicing performance. The excellent electro-thermal performance facilitates the usage of cement composite in Joule heating applications, such as indoor climate control, pavement deicing, and cooking, thus considerably broadening the applications of cement and concrete composites for a sustainable and resilient future. [Display omitted] • A novel conductive cement composite is fabricated based on heat treatment of expandable graphite. • The obtained composite exhibit excellent electro-thermal performance with a homogeneous heat distribution. • The mechanism of the newly formed conductive network after graphite expansion was investigated. [ABSTRACT FROM AUTHOR]

In this study, a single firing was used to convert stabilized polyacrylonitrile (PAN) fibers and ceramic forming materials (kaolin, feldspar, and quartz) into carbon fiber/ceramic composites. For the first time, PAN carbonization and ceramic sintering were achieved simultaneously in one thermal cycle and the microscopic morphologies and physical features of the obtained carbon fiber/ceramic composites were characterized in detail. The obtained carbon fiber/ceramic composite showed comparable flexural strength as commercial ceramic tiles. Meanwhile, the composite showed exceptional electro-thermal performance based on the electro-thermal performance of the carbonized PAN fibers, which could reach 108 ℃ after 15 s, 204 ℃ after 90 s, and 292 ℃ after 450 s at 5 V (2.6 A), thereby making the ceramic composite a good candidate as an indoor climate control heater, defogger device, kettle, and other heating element.

In this work, a personal thermal management (PTM) device based on single walled carbon nanotubes (SWCNTs) functionalized polyester fabrics had been studied. Polyester fabrics were functionalized with SWCNTs through coating method with poly (butyl acrylate) emulsion as the adhesive. The SEM images exhibited that SWCNTs formed high-efficiently conductive networks due to the large aspect ratio and uniform dispersion. A steady-state temperature of 40 °C was achieved at the input voltage of 2.5 V within 7 s, which exhibited excellent electro-thermal performance. Even under periodic heating-cooling conditions, heating system still displayed relatively stable temperature and relative resistance, which could have potential application for wearable clothes. [ABSTRACT FROM AUTHOR]

• Electrically conductive roller-compacted concrete is proposed for overwintering layer of dams. • ERCC layer provide a new way to solve the thermal crack problem of RCC dams. • The electro-thermal properties and resistivity variation of ERCC are evaluated. • The compaction properties of ERCC are assessed by rolling compacted device. • Larger density and strength shows the superiority of rolling construction method. To solve the thermal crack problem of overwintering layer of roller-compacted concrete (RCC) dams. A new type of intelligent hydraulic concrete, namely electrically conductive roller-compacted concrete (ERCC), was designed. ERCC layer could provide a new way to control the temperature distribution and reduce the cracking likelihood of RCC dams by its electro-thermal properties, closely related to the variation of resistivity of ERCC. Thus, the relationships between design factors and the resistivity were investigated to obtain the real resistivity of ERCC layer of RCC dams. Then the temperature increase of ERCC layer with the size of 3000 × 700 × 200 mm was measured under 30 V direct current voltage. The temperature rises 14 ~ 16 ℃ within 235 min. It means that the electro-thermal properties of ERCC are enough to resist cold waves in winter. On the other hand, the mechanical and compaction properties of ERCC were investigated through experiments to evaluate whether the roller compaction method can overcome the poor fluidity and improve the construction quality of ERCC. So the density and strength of roller compacted device formed ERCC were compared with those of vibration formed ERCC, which shows the superiority of rolling construction method. According to unit compaction energy and parameters of the roller machines, the onsite compaction passes N S are calculated, which provides guidance for the construction of overwintering layer. In summary, selecting ERCC as the overwintering material instead of traditional thermal insulation materials could provide a more flexible and intelligent temperature control way for RCC dams in the severe cold areas, signifying ERCC is a promising material in hydraulic engineering. [ABSTRACT FROM AUTHOR]