Conductive Ti3C2Tx MXenes have been widely investigated for the construction of flexible and highly-sensitive pressure sensors. Although the inevitable oxidation of solution-processed MXene has been recognized, the effect of the irreversible oxidation of MXene on its electrical conductivity and sensing properties is yet to be understood. Herein, we construct a highly-sensitive and degradable piezoresistive pressure sensor by coating Ti3C2Tx MXene flakes with different degrees of in situ oxidation onto paper substrates using the dipping-drying method. In situ oxidation can tune the intrinsic resistance and expand the interlayer distance of MXene nanosheets. The partially oxidized MXene-based piezoresistive pressure sensor exhibits a high sensitivity of 28.43 kPa−1, which is greater than those of pristine MXene, over-oxidized MXene, and state-of-the-art paper-based pressure sensors. Additionally, these sensors exhibit a short response time of 98.3 ms, good durability over 5000 measurement cycles, and a low force detection limit of 0.8 Pa. Moreover, MXene-based sensing elements are easily degraded and environmentally friendly. The MXene-based pressure sensor shows promise for practical applications in tracking body movements, sports coaching, remote health monitoring, and human–computer interactions. 

Flexible and highly‐sensitive pressure sensor based on controllably oxidized MXene

This article deals with explores to review of the recent advances in wearable electronics using textile-based flexible and printable materials (TFPMs) for the next generation of wearable and flexible electronic devices. Among different types of wearable electronics, flexible electronics, and electronic sensors, which integrate flexible textiles with the better functions of electronic devices as well as printable energy storage devices. Firstly, we review recent progress in electronic devices, focusing on newly improved the design of TFPMs and fabrication strategies. Their applications and performances in sensors, supercapacitors, flexible conductive electrodes, and triboelectric nanogenerators are discussed as presented in various articles. Then, the manufacturing methods and applications of TFPMs are outlined in detail. Moreover, the integration of versatile e-textiles has significantly improved with enhanced optic-electrical, electrochemical, and mechanical properties. Finally, we discuss the challenges that exist and the future work opportunities to develop electronic textiles through experimental and simulation research. 

Textile-based Flexible and Printable Sensors for Next Generation Uses and Their Contemporary Challenges: A Critical Review

Electronic textiles (e‐textiles) have drawn significant attention from the scientific and engineering community as lightweight and comfortable next‐generation wearable devices due to their ability to interface with the human body, and continuously monitor, collect, and communicate various physiological parameters. However, one of the major challenges for the commercialization and further growth of e‐textiles is the lack of compatible power supply units. Thin and flexible supercapacitors (SCs), among various energy storage systems, are gaining consideration due to their salient features including excellent lifetime, lightweight, and high‐power density. Textile‐based SCs are thus an exciting energy storage solution to power smart gadgets integrated into clothing. Here, materials, fabrications, and characterization strategies for textile‐based SCs are reviewed. The recent progress of textile‐based SCs is then summarized in terms of their electrochemical performances, followed by the discussion on key parameters for their wearable electronics applications, including washability, flexibility, and scalability. Finally, the perspectives on their research and technological prospects to facilitate an essential step towards moving from laboratory‐based flexible and wearable SCs to industrial‐scale mass production are presented.

Smart Electronic Textile‐Based Wearable Supercapacitors

Recently, hydrogels (HYD) have garnered tremendous interest because of their potential uses in sensors, flexible energy storing gadgets, [email protected] systems, soft electronics and actuating machines. As a result of their inherent exhibition of hydrophilicity, metallically inclined conductivity, elevated aspect ratio, architectural disposition along with tune-able attributes, when 2-D transitionally inclined metallic carbides/nitrides or M−X are embedded within HYD systems, they give enchanting and wide settings for the fabrication of M−X oriented soft materials with tunable applicability and multifunctional properties. M−[email protected] bionanoarchitectures exceptional properties are propelled by intricate gel architectures along with gelation strategies, requiring versatile studies and engineering at the nanoscale. Nevertheless, M−X embedment within HYD can notably increment M−X stability, which regularly is an inhibiting parameter for varying M−X oriented uses. Nevertheless, through simplified modifications, M−[email protected] derivatives like aerogels, are liable to be garnered, thereby broadening their horizon. Therefore, this elucidation presents recently emerging trends in M−[email protected] architectures, multifunctional applications and enhancement of the performance of M−X−oriented gadgets. Herein, the prevailing architectures of varying M−[email protected] constructions as well as inherent gelation mechanisms along with their interlinkage propelling forces are elucidated. Their unique properties and multifunctional applications (electromagnetic interference shielding, biomedicals, energy storage/harvesting, sensing and catalysis), emanating from embedment of M−X within HYD are comprehensively and elaborately elucidated in this review paper. 

Recent Trends in MXene Polymeric Hydrogel Bionanoarchitectures and Applications

An all-fibrous large-area (20 × 50 cm2 ) tailorable triboelectric nanogenerator (LT-TENG) is prepared using a one-step solution blow spinning technology, which has the advantages of easy operation, scale-up in the area, and high production efficiency. The prepared LT-TENG is composed of polyvinylidene fluoride (PVDF)/MXene (Ti3 C2 Tx ) nanofibers (NFs) and conductive textile. Benefiting from the fibrous materials and large-area properties, the LT-TENG possesses the merits of good tailorability, breathability, hydrophobicity, and washability. When optimized by mixing the MXene into PVDF NFs, the LT-TENG has a preferable output and sensing property, with a detection range over 16 kPa and a relatively high sensitivity of 12.33 V KPa-1 . At maximum applied pressure, the voltage, current, and charge are 108 V, 38 µA, and 35 nC, respectively. This LT-TENG can serve as a biomechanical energy harvester when used as wearable devices with an output power density of 12.6 mW m-2 at an external load resistance of 500 MΩ, and it also has the ability of self-powered tactile sensing for pressure mapping and slide sensing. Thus, this LT-TENG exhibits great potential prospects in wearable devices, intelligent robots, and human-machine interaction.

Fully Fibrous Large-Area Tailorable Triboelectric Nanogenerator Based on Solution Blow Spinning Technology for Energy Harvesting and Self-Powered Sensing.

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

Repeatable dual‐encryption platforms, coupled with a strong protective capacity for stored information, are highly desirable for current data security but still a challenge to be realized. Herein, a new type of thermoset‐based repeatable dual‐encryption platform is designed to fulfill the challenge. Through introducing dynamic boroxine bonds and hydrogen bonds within the thermoset, self‐healing, recyclability, and shape‐memory properties can be achieved. Given the shape memory behavior of this thermoset, encryption data within complex 3D structures can be realized. Thus, shape recovery is inevitable for the decryption, providing strong protection for encrypted data. Furthermore, the encrypted data can be protected by showing misleading information before true information during the decryption process, which is caused by the different analogous “LEGO” assembly sequences of thermosets that induces different hydrophobic association interactions. The decrypted information can be erased by heating, realizing the repeatable encryption/decryption. Additionally, the thermosets can be efficiently recycled. This strategy opens up a smart prospect for high level dual‐encryption platform.

A Repeatable Dual‐Encryption Platform from Recyclable Thermosets with Self‐Healing Ability and Shape Memory Effect

Textile-based flexible and wearable electronic devices provide an excellent solution to thermal management systems, thermal therapy, and deicing applications through the Joule heating approach. However, challenges persist in designing such cost-effective electronic devices for efficient heating performance. Herein, this study adopted a facile solution-processed strategy, “dip-coating”, to develop a high-performance Joule heating device by unformly coating the intrinsically conducting polymer (CP) poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) onto the surface of cotton textiles. The structural and morphological attributes of the cotton/CP mixture were evaluated using various characterization techniques. The electrothermal characteristics of the cotton/CP sample included rapid thermal response, uniform surface temperature distribution up to 94 °C, excellent stability, and endurance in heating performance under various mechanical deformations. The real-time illustration of the fabric heater affixed on a human finger has demonstrated its outstanding potential for thermal therapy applications. The fabricated heater may further expand it purposes toward deicing, defogging, and defrosting applications.

Synthesis of PEDOT:PSS Solution-Processed Electronic Textiles for Enhanced Joule Heating

Recently, with the advancement of material science and manufacturing methods, researchers have introduced many new and advanced materials for wearable sensors. Especially, incredible advancement has been noticed in flexible strain...

/pdf/cellulose-based-flexible-and-wearable-sensors-for-health-uhhge6lj.pdf

Cellulose Based Flexible and Wearable Sensors for Health Monitoring

Recently, nanostructured carbon‐based soft bioelectronics and biosensors have received tremendous attention due to their outstanding physical and chemical properties. The ultrahigh specific surface area, high flexibility, lightweight, high electrical conductivity, and biocompatibility of 1D and 2D nanocarbons, such as carbon nanotubes (CNT) and graphene, are advantageous for bioelectronics applications. These materials improve human life by delivering therapeutic advancements in gene, tumor, chemo, photothermal, immune, radio, and precision therapies. They are also utilized in biosensing platforms, including optical and electrochemical biosensors to detect cholesterol, glucose, pathogenic bacteria (e. g., coronavirus), and avian leucosis virus. This review summarizes the most recent advancements in bioelectronics and biosensors by exploiting the outstanding characteristics of nanocarbon materials. The synthesis and biocompatibility of nanocarbon materials are briefly discussed. In the following sections, applications of graphene and CNTs for different therapies and biosensing are elaborated. Finally, the key challenges and future perspectives of nanocarbon materials for biomedical applications are highlighted.

Abbas Mohamed Ahmed

Papers

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

A Repeatable Dual‐Encryption Platform from Recyclable Thermosets with Self‐Healing Ability and Shape Memory Effect

Synthesis of PEDOT:PSS Solution-Processed Electronic Textiles for Enhanced Joule Heating

Cellulose Based Flexible and Wearable Sensors for Health Monitoring

Nanostructured Carbons: Towards Soft‐Bioelectronics, Biosensing and Theraputic Applications