New Carbon Materials for Multifunctional Soft Electronics.

Soft electronics are garnering significant attention due to their wide-ranging applications in artificial skin, health monitoring, human-machine interaction, artificial intelligence, and the Internet of Things. Various soft physical sensors such as mechanical sensors, temperature sensors, and humidity sensors are the fundamental building blocks for soft electronics. While the fast growth and widespread utilization of electronic devices have elevated life quality, the consequential electromagnetic interference (EMI) and radiation pose potential threats to device precision and human health. Another substantial concern pertains to overheating issues that occur during prolonged operation. Therefore, the design of multifunctional soft electronics exhibiting excellent capabilities in sensing, EMI shielding, and thermal management is of paramount importance. Because of the prominent advantages in chemical stability, electrical and thermal conductivity, and easy functionalization, new carbon materials including carbon nanotubes, graphene and its derivatives, graphdiyne, and sustainable natural-biomass-derived carbon are particularly promising candidates for multifunctional soft electronics. This review summarizes the latest advancements in multifunctional soft electronics based on new carbon materials across a range of performance aspects, mainly focusing on the structure or composite design, and fabrication method on the physical signals monitoring, EMI shielding, and thermal management. Furthermore, the device integration strategies and corresponding intriguing applications are highlighted. Finally, this review presents prospects aimed at overcoming current barriers and advancing the development of state-of-the-art multifunctional soft electronics.

A visual diagnostic detection of Helicobacter pylori and the gastric carcinoma-related virulence genes (cagA and vacA) by a fluorescent loop-mediated isothermal amplification (LAMP).

Helicobacter pylori (H. pylori) infection has increasingly been a serious problem worldwide. The H. pylori infection can result in a series of stomach diseases including gastric carcinoma. There are two specific virulence genes (cagA and vacA) of H. pylori that are closely related to the occurrence of gastric cancer, and the common molecular detection methods (PCR, qPCR) are not suitable for high-screening test due to the requirement of expensive instruments and well-trained personals. Herein, we develop a rapid visual assay based on loop-mediated isothermal amplification (LAMP) for detecting H. pylori and its major virulence genes (cagA, vacAs1 and vacAm1) to guide clinical treatment for H. pylori infection. In this research, a fluorescent LAMP assay was established by optimizing the indicator of MnCl2-Calcein, so that the resulted color and fluorescence changes could be utilized to perform the visual detection for H. pylori and its virulence genes with high sensitivity (10-3 ng/µL). The proposed LAMP assay is simple, fast (30 min) and capable in providing more sensitive results than traditional methods in the test of 46 clinical biopsy samples. By detecting the three virulence genes together, we can profile the infection risk of the patients, and discuss the correlation among the genes. Moreover, the method could be used to diagnose virulently infected individuals and benefit the eradication of H. pylori in early warning for gastric cancer.

Recent Advances in Design Strategies and Multifunctionality of Flexible Electromagnetic Interference Shielding Materials.

With rapid development of 5G communication technologies, electromagnetic interference (EMI) shielding for electronic devices has become an urgent demand in recent years, where the development of corresponding EMI shielding materials against detrimental electromagnetic radiation plays an essential role. Meanwhile, the EMI shielding materials with high flexibility and functional integrity are highly demanded for emerging shielding applications. Hitherto, a variety of flexible EMI shielding materials with lightweight and multifunctionalities have been developed. In this review, we not only introduce the recent development of flexible EMI shielding materials, but also elaborate the EMI shielding mechanisms and the index for "green EMI shielding" performance. In addition, the construction strategies for sophisticated multifunctionalities of flexible shielding materials are summarized. Finally, we propose several possible research directions for flexible EMI shielding materials in near future, which could be inspirational to the fast-growing next-generation flexible electronic devices with reliable and multipurpose protections as offered by EMI shielding materials.

Soft Organic Thermoelectric Materials: Principles, Current State of the Art and Applications.

The enormous demand for waste heat utilization and burgeoning eco-friendly wearable materials has triggered huge interest in the development of thermoelectric materials that can harvest low-cost energy resources by converting waste heat to electricity efficiently. In particular, due to their high flexibility, nontoxicity, cost-effectivity, and promising applicability in various fields, organic thermoelectric materials are drawing more attention compared with their toxic, expensive, heavy, and brittle inorganic counterparts. Organic thermoelectric materials are approaching the figure of merit of the inorganic ones via the construction and optimization of unique transport pathways and device geometries. This review presents the recent development of the interdependence and decoupling principles of the thermoelectric efficiency parameters as well as the new achievements of high performance organic thermoelectric materials. Moreover, this review also discusses the advances in the thermoelectric devices with emphasis on their energy-related applications. It is believed that organic thermoelectric materials are emerging as green energy alternatives rivaling their conventional inorganic counterparts in the efficient and pure electricity harvesting from waste heat and solar thermal energy.

Ultralight, Conductive Ti3C2Tx MXene/PEDOT:PSS Hybrid Aerogels for Electromagnetic Interference Shielding Dominated by the Absorption Mechanism.

MXene aerogels with a porous microstructure are a promising electromagnetic interference (EMI) shielding material due to its low density and excellent electrical conductivity, which has attracted widespread attention. Compared with traditional EMI shielding materials that rely on reflection as the primary mechanism, MXene aerogels with absorption as the dominant mechanism have greater potential for development as a novel EMI shielding material because of its ability to reduce environmental contamination from reflected electromagnetic (EM) waves from materials. In this study, a novel Ti3C2Tx MXene/PEDOT:PSS hybrid aerogel was presented by freeze-drying and thermal annealing using few-layered Ti3C2Tx MXene and the conductive polymer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS). PEDOT:PSS not only improved the gelling ability of Ti3C2Tx but also successfully established a conductive bridge between MXene nanosheets. The experimental results demonstrated that the hybrid aerogel exhibited an obvious porous microstructure, which was beneficial for the multiple scattering of EM waves within the materials. The EMI shielding effectiveness and specific shielding effectiveness reached up to 59 dB and 10,841 dB·cm2·g-1, respectively, while the SER/SET ratio value was only 0.05, indicating superior wave absorption performance. Furthermore, the good impedance matching, due to the electrical conductance loss and polarization loss effect of the composites, plays a critical role in their excellent wave absorption and EMI shielding performance. Therefore, this work provides a practical approach for designing and fabricating lightweight absorption-dominated EMI shielding materials.

Bioinspired wood-like coaxial fibers based on MXene@graphene oxide with superior mechanical and electrical properties.

MXenes, a new class of two-dimensional materials with excellent performance, are promising materials for wearable energy storage devices. However, the lack of sufficient interaction between various MXene particles makes it difficult to translate the exceptional performance from the nanoscale to macroscale. Additionally, the intrinsic characteristic of easy oxidation limits their practical applications. Herein, inspired by the structure of wood, a biomimetic core-shell MXene@graphene oxide (MX@GO) fiber was fabricated using GO as a mechanical layer to wrap MXenes. The GO layer could easily assemble MXene particles into macroscale materials and protect them from oxidation. Therefore, the as-fabricated core-shell MX@GO fiber showed a high tensile strength (290 MPa) and excellent electrical conductivity (2400 S m-1). Notably, the conductivity of the biomimetic fiber only decreased to 1800 S m-1 with a reduction of about 30% at 100 °C. This work paves the way to fabricate MXene-based fibers with freely designed functionalities and morphologies, which are suitable for various high-value fabric-based applications.

Electromagnetic Interference Shielding of Graphene Aerogel with Layered Microstructure Fabricated via Mechanical Compression.

Graphene aerogel is a promising electromagnetic interference (EMI) shielding material because of its light weight, excellent electrical conductivity, uniform three-dimensional (3D) microporous structure, and good mechanical strength. The graphene aerogel with high EMI shielding performance is attracting considerable critical attention. In this study, a novel procedure to fabricate high EMI shielding graphene aerogel was presented, inspired by the irreversible deformation of hydrogels under mechanical pressure. The procedure involved a mechanical compression step on graphene hydrogels for the purpose of altering microstructures followed by freeze-drying and thermal annealing at 900 °C to generate the final products. Because of the flow of internal liquid caused by mechanical compression, the microstructures of hydrogels changed from a cellular configuration to a layered configuration. After a high degree of compression, GAs can be endowed with homogeneous layered structure and high density, which plays a leading role in electromagnetic wave dissipation. Consequently, the aerogels with excellent electrical conductivity (181.8 S/m) and EMI shielding properties (43.29 dB) could be obtained. Besides, the compression process enabled us to form complex hydrogel shapes via different molds. This method enhances the formability of graphene aerogels and provides a robust way to control the microstructure.