The purpose of this paper is to provide a source of information on thermal energy use in buildings, its drivers, and their past, present and future trends on a global and regional basis. Energy use in buildings forms a large part of global and regional energy demand. The importance of heating and cooling in total building energy use is very diverse with this share varying between 18% and 73%. Biomass is still far the dominant fuel when a global picture is considered; the role of electricity is substantially growing, and the direct use of coal is disappearing from this sector, largely replaced by electricity and natural gas in the most developed regions. This paper identifies the different drivers of heating and cooling energy demand, and decomposes this energy demand into key drivers based on a Kaya identity approach: number of households, persons per household, floor space per capita and specific energy consumption for residential heating and cooling; and GDP, floor space per GDP, and specific energy consumption for commercial buildings. This paper also reviews the trends in the development of these drivers for the present, future – and for which data were available, for the past – in 11 world regions as well as globally. Results show that in a business-as-usual scenario, total residential heating and cooling energy use is expected to more or less stagnate, or slightly decrease, in the developed parts of the world. In contrast, commercial heating and cooling energy use will grow in each world region. Finally, the results show that per capita total final residential building energy use has been stagnating in the vast majority of world regions for the past three decades, despite the very significant increases in energy service levels in each of these regions.

Heating and cooling energy trends and drivers in buildings

Wearable electronics offer incredible benefits in mobile healthcare monitoring, sensing, portable energy harvesting and storage, human-machine interactions, etc., due to the evolution of rigid electronics structure to flexible and stretchable devices. Lately, transition metal carbides and nitrides (MXenes) are highly regarded as a group of thriving two-dimensional nanomaterials and extraordinary building blocks for emerging flexible electronics platforms because of their excellent electrical conductivity, enriched surface functionalities, and large surface area. This article reviews the most recent developments in MXene-enabled flexible electronics for wearable electronics. Several MXene-enabled electronic devices designed on a nanometric scale are highlighted by drawing attention to widely developed nonstructural attributes, including 3D configured devices, textile and planer substrates, bioinspired structures, and printed materials. Furthermore, the unique progress of these nanodevices is highlighted by representative applications in healthcare, energy, electromagnetic interference (EMI) shielding, and humanoid control of machines. The emerging prospects of MXene nanomaterials as a key frontier in next-generation wearable electronics are envisioned and the design challenges of these electronic systems are also discussed, followed by proposed solutions. 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/inf2.12295

Two‐dimensional MXenes
 : New frontier of wearable and flexible electronics

Personal thermal management techniques for thermal comfort and building energy saving

Multifunctional fiber‐reinforced polymer (FRP) composites provide an ideal platform for next‐generation smart composites applications including structural health monitoring, electrical and thermal conductivity, energy storage and harvesting, and electromagnetic interference shielding without compromising their mechanical properties. Recent progress in carbon‐based nanomaterials such as graphene and carbon nanotubes (CNTs) has enabled the development of many novel multifunctional composites with excellent mechanical, electrical, and thermal properties. However, the effective incorporation of such carbon nanomaterials into FRP composites using scalable, high‐speed, and cost‐effective manufacturing without compromising their performance is challenging. This review summarizes the recent progress on graphene and CNT‐based FRP composites, their manufacturing techniques, and their applications in smart composites. Current technical challenges and future perspectives on smart FRP composites research to facilitate an essential step toward moving from research and development‐based smart composites to industrial‐scale mass production are also discussed.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/adfm.202205723

Graphene and CNT‐Based Smart Fiber‐Reinforced Composites: A Review

The advances in the nanotechnology and materials chemistry research has revolutionized the field of stretchable, flexible, and wearable electronics for next-generation applications. Specifically, the exploration and progress of MXene have made a remarkable breakthrough in modern materials chemistry research to fabricate and design high-performance wearable electronics. MXene has been extensively studied to design flexible and wearable devices by integrating them with highly flexible conducting polymers to improve their performance and impart new functionalities. This review summarizes the recent advances of MXene integrated conducting polymers (MXCP) to design composite structures for wearable electronics. Synthesis of MXene and strategies to fabricate MXCP composites are highlighted along with their mechanical and electrical properties. Different applications of MXCP in energy storage, electromagnetic shielding, personal thermal management, sensors and bioelectronics are discussed. The review also suggests the routes towards exploring the vast potential of MXCP composites for wearable electronic applications.

Al Mojnun Shamim

Papers

Functional textiles and composite based wearable thermal devices for Joule heating: progress and perspectives