Powered by market hype, trends among youth, and enormous funds, wearable technology has propelled itself as one of the most discussed topics in the field during past few years. A number of different companies representing all throughout the world have already entered into the market with hundreds of different products like smart watches, fitness trackers, smart garments, and even different smart medical attachments.Together with the evolution of digital health care, the wearable electronics field has evolved rapidly during the past few years and is expected to be expanded even further within the first few years of the next decade. As the next stage of wearables is predicted to move toward integrated wearables, nanomaterials and nanocomposites are in the spotlight of the search for novel concepts for integration. In addition, the conversion of current devices and attachment-based wearables into integrated technology may involve a significant size reduction while retaining their functional capabilities. Nanomaterialbased wearable sensors have already marked their presence with a significant distinction while nanomaterial-based wearable actuators are still at their embryonic stage. This review looks into the contribution of nanomaterials and nanocomposites to wearable technology with a focus on wearable sensors and actuators.

Copper has been widely used in many applications due to its outstanding properties such as malleability, high corrosion resistance, and excellent electrical and thermal conductivities. While 3D printing can offer many advantages from layer-by-layer fabrication, the 3D printing of highly pure copper is still challenging due to the thermal issues caused by copper’s high conductivity. This paper presents a comprehensive review of recent work on 3D printing technology of highly pure copper over the past few years. The advantages and current issues of 3D printing methods are compared while different properties of copper parts printed by these methods are summarized. Finally, we provide several potential applications of the 3D printed copper parts and an overview of current developments that could lead to new improvements in this advanced manufacturing field.

Constructing heterointerfaces between metals and metal compounds is an attractive strategy for the fabrication of high performance electrocatalysts. However, realizing the high degree of fusion of two different metal components to form heterointerfaces remains a great challenge, since the different metal components tend to grow separately in most cases. Herein, by employing carboxyl-modified carbon nanotubes to stabilize different metal ions, the engineering of abundant Ni|MnO heterointerfaces is achieved in porous carbon nanofibers (Ni|MnO/CNF) during the electrospinning-calcination process. Remarkably, the resulting Ni|MnO/ CNF catalyst exhibits activities that are among the best reported for the catalysis of both the oxygen reduction and oxygen evolution reactions. Moreover, the catalyst also demonstrates high power density and long cycle life in Zn-air batteries. Its superior electrochemical properties are mainly ascribed to the synergy between the engineering of oxygen-deficient Ni|MnO heterointerfaces with a strong Ni/Mn alloying interaction and the 1D porous CNF support. This facile anchoring strategy for the initiation of bimetallic heterointerfaces creates appealing opportunities for the potential use of heteronanomaterials in practical sustainable energy applications.

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Intelligent materials, also known as smart materials, are capable of reacting to various external stimuli or environmental changes by rearranging their structure at a molecular level and adapting functionality accordingly. The initial concept of the intelligence of a material originated from the natural biological system, following the sensing–reacting–learning mechanism. The dynamic and adaptive nature, along with the immediate responsiveness, of the polymer- and fiber-based smart materials have increased their global demand in both academia and industry. In this manuscript, the most recent progress in smart materials with various features is reviewed with a focus on their applications in diverse fields. Moreover, their performance and working mechanisms, based on different physical, chemical and biological stimuli, such as temperature, electric and magnetic field, deformation, pH and enzymes, are summarized. Finally, the study is concluded by highlighting the existing challenges and future opportunities in the field of intelligent materials.