Advances in MXene-Based Hybrids for Electrochemical Health Monitoring

This paper reports on the study of best practices in evaluation methodologies for aging in place technologies, and analyses their feasibility in a pandemic environment. The pandemic situation, with various physical distancing restrictions in place, especially for vulnerable older adults, has increased the importance of deploying health monitoring and social interaction technologies for aging in place. The pandemic also made it more difficult for researchers and developers of technologies to evaluate the usability of home health monitoring technologies. Existing technology evaluation methods mostly involve laboratory and home technology usability evaluations that could be problematic during physical distancing restrictions, and are not well suited for rapid evaluation of health monitoring technologies. The increasing trend in virtual doctor and health professional visits puts additional pressure to speed up innovation for home health and wellness monitoring and communication technologies without increasing risks for vulnerable populations. Researchers observed challenges with performing HCI research with older adults in a pandemic situation, including challenges with participant recruitment, obtaining informed consent for the study, shipping technology to the willing participants, assessing the ability of older adults to set up both digital health technology and remote usability tools, and research data collection. The need for low cost, low risk, easy to use and privacy-preserving usability evaluation methods and tools for home health monitoring is growing rapidly, and new remote usability evaluation methods and tools will add to the growing arsenal of digital technologies used in the public health response to COVID-19 and beyond.

MXenes, a rapidly growing family of two-dimensional (2D) transition metal carbides, nitrides, or carbonitrides (Mn+1XnTx, where M is a transition metal, X is carbon, nitrogen, or both, and T represents surface functional groups), have captured the scientific community's interest due to their exceptional physicochemical properties and diverse technological applications. This comprehensive review explores the latest breakthroughs in MXene synthesis and characterisation, emphasising their multifaceted applications in energy storage, catalysis, sensing, and other cutting-edge domains. This review examines the most widely used MXene synthesis strategies, including selective etching and delamination, and highlight recent advancements in controlling surface terminations, composition, and morphology. The influence of these synthetic parameters on MXene properties is discussed in detail. Characterisation techniques, ranging from spectroscopic methods to electron microscopy, are essential for elucidating MXenes' structure-property relationships. Research into energy storage leverages MXenes' high electrical conductivity, large surface area, and chemical tunability. This has led to significant progress in the field. This paper presents research efforts focused on optimising MXenes for both battery and supercapacitor applications. Additionally, the catalytic prowess of MXenes, particularly in electrocatalysis and photocatalysis, is explored, emphasising their role in green energy technologies and environmental remediation. MXenes' remarkable sensitivity and selectivity make them promising candidates for sensing various gases, biomolecules, and ions, offering exciting possibilities in healthcare and environmental monitoring. Importantly, this review underscores the need for continued optimisation of MXene synthesis protocols to achieve large-scale production, enhanced stability, and precise control over properties across various fields.

Interfacial structure design of MXene-based nanomaterials for supercapacitors and batteries

Two-dimensional (2D) transition metal carbides and nitrides (MXenes) have recently attracted much attention because of their electronic structure and properties that differ from their bulk counterparts [1]. MXenes were first discovered at Drexel University in 2011 [2] by selective chemical etching of aluminum layers from ternary transition metal carbides known as MAX. The general chemical formula of MXene is written as (Mn+1XnTx) [3], where M is an early transition metal (Ti, Nb, Ta, V, Mo, etc.), X is C and/or N, and n = 1- 3 [4]. Due to the chemical synthesis in fluorine-containing solution MXene have surface functional groups (Tx), which can be fluorine (-F), oxygen (-O), or hydroxyl (-OH) groups [3, 4]. Most chemically synthesized MXenes are hydrophilic and some exhibit high electrical conductivity [5, 6]. More than 20 different MXenes have been experimentally synthesized and several more varieties of MXenes have been predicted, rendering MXenes among the most diverse, tunable and fastest growing 2D materials [3]. MXenes have already shown a promising performance in many applications such as energy storage [7], electromagnetic interference shielding [8], water desalination [9], and optoelectronics [10]. However, the moiety and quantity of the surface functional groups have been shown to be dependent on the synthesis conditions [11], and shown to affect the quality and properties of MXene [5, 12]. Here, we systematically study the thermal stability as well as the surface moieties of MXenes, namely (Ti3C2Tx, Mo2CTx, Mo2TiC2Tx and Mo2Ti2C2Tx), using simultaneous thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) from ambient temperature to 1500 °C. We also discuss the effect of MXene synthesis, that is etchant type and concentration, on surface functional groups. For example, the amount of –OH, –F, and structural water is different and dependent on varying the composition of fluorine-containing etchants. Also, the thermal stability of MXenes strongly depends on their chemical composition. This study sheds lights on the importance of synthesis conditions in controlling MXenes compositions, structure and their surfaces for a variety of potential applications. References Naguib M. Two-dimensional transition-metal carbides and carbonitrides, In: Nanomaterials Handbook, 2ed. Advanced Materials and Technologies Series (Ed. Gogotsi Y.), 2017, Boca Raton: Taylor & Francis Group, CRC Press, pp. 83-103.Naguib M., Kurtoglu M., Presser V., Lu J., Niu J., Heon M., Hultman L., Gogotsi Y., Barsoum M.W. Two-dimensional nanocrystals produced by exfoliation of Ti3AlC2. Adv. Mater. 2011, 23, 4248-4253.Anasori B., Lukatskaya M. R., Gogotsi Y. 2D metal carbides and nitrides (MXenes) for energy storage. Nature Rev. Mater. 2017, 16098, 1-17.Naguib M., Gogotsi Y. Synthesis of two-dimensional materials by selective extraction. Acc. Chem. Res.2015, 48, 128-135.Alhabeb M., Maleski K., Anasori B., Lelyukh P., Clark L., Sin S., Gogotsi Y. Guidelines for synthesis and processing of two-dimensional titanium carbide (Ti3C2Tx MXene). Chem. Mater. 2017 29, 7633-7644.Maleski K., Mochalin V.N., Gogotsi Y. Dispersions of two-dimensional titanium carbide MXene in organic solvents. Chem. Mater. 2017, 29, 1632-1640.Lukatskaya M. R., Kota S., Lin Z., Zhao M.-Q., Shpigel N., Levi M. B., Halim J., Taberna P.-L., Barsoum M. W., Simon P., Gogotsi Y. Ultra-high-rate pseudocapacitive energy storage in two-dimensional transition metal carbides. Nature Energy 2017, 2, 17105.Shahzad F., Alhabeb M., Hatter C., Anasori B., Hong S. M., Koo C. M., Gogotsi Y. Electromagnetic interference shielding with 2D transition metal carbides (MXenes). Science 2016, 353, 1137-1140.Ren C. E., Hatzell K. B., Alhabeb M., Ling Z., Mahmoud K., Gogotsi Y. Charge- and size-selective ion sieving through Ti3C2Tx MXene membranes. J. Phys. Chem. Lett. 2015, 6, 4026-4031.Jhon Y. I., Koo J., Anasori B., Seo M., Lee J. H., Gogotsi Y., Jhon Y. M. Metallic MXene saturable absorber for femtosecond mode-locked lasers. Adv. Mater. 2017, 29, 1702496 (1-8).Hope M. A., Forse A. C., Griffith K. J., Lukatskaya M. R., Ghidiu M., Gogotsi Y., Grey C. P. NMR reveals the surface functionalisation of Ti3C2 MXene. Phys. Chem. Chem. Phys. 2016, 18, 5099-5102.Sang X., Xie Y., Lin M.-W., Alhabeb M., Van Aken K. L., Gogotsi Y., Kent P. R. C., Xiao K., Unocic R. R. Atomic defects in monolayer titanium carbide (Ti3C2Tx) MXene. ACS Nano, 2016, 10, 9193-9200

Health monitoring is one of the many industries that has been transformed by the Internet of Things' (IoT) explosive growth. A thorough bibliometric analysis, cluster analysis, and term occurrences analysis are used in this study to reveal the complex world of IoT technology in health monitoring. Thematic groups are shown by cluster analysis, essential insights are provided by highly cited publications, and key concepts are clarified by word occurrences. The multidisciplinary aspect of research is exemplified by collaborative networks, prominent contributions, and rising trends within the literature. The amalgamation of results offers a comprehensive comprehension of the present condition of IoT in health monitoring, steering forthcoming research directions and promoting sustained innovation at the nexus of technology and healthcare.

Current maintenance programmes for key aircraft systems such as the landing gears are made up of several activities based around preventive and corrective maintenance scheduling. Within today’s competitive aerospace market innovative maintenance solutions are required to optimise aircraft maintenance, for both single aircraft and the entire fleet, ensuring that operators obtain the maximum availability from their aircraft. This has led to a move away from traditional preventive maintenance measures to a more predictive maintenance approach, supported by new health monitoring technologies. Future aircraft life will be underpinned by health monitoring, with the ability to quantify the health of aerospace systems and structures offering competitive decision-making advantages that are now vital for retaining customers and attracting new business. One such aerospace system is the actuator mechanisms used for extension, retraction and locking of the landing gears. The future of which will see the introduction of electromechanical replacements for the hydraulic systems present on the majority of civil aircraft. These actuators can be regarded as mission critical systems that must be guaranteed to operate at both take-off and landing. The health monitoring of these actuation systems can guarantee reliability, reduce maintenance costs and increase their operational life span. Aerospace legislation dictates that any decisions regarding maintenance, safety and flight worthiness must be justified and strict procedures followed. This has inevitably led to difficulties in health monitoring solutions meeting the necessary requirements for aerospace integration. This paper provides the motivation for the research area through reviewing current aircraft maintenance practices and how health monitoring is likely to play a future strategic role in maintenance operations. This is achieved with reference to current research work into developing a health monitoring system to support novel electromechanical actuators for use in aircraft landing gears. The difficulties associated with integrating new health monitoring technology into an aircraft are also reviewed, with perspectives given on the reasons for the current slow integration of health monitoring systems into aerospace.

RETRACTED: MXene/metal and polymer nanocomposites: Preparation, properties, and applications

It is a great pleasure and honor to welcome you to the First IEEE-EMBS Special Topic Conference on Point-Of-Care (POCT) Healthcare Technologies that will focus on innovation, research, technology development and best practices in deployment of health monitoring technologies in developing and developed economies for better global healthcare. The conference will feature research presentations and technology panel discussions and forums on recent technological advances and global issues on implementation of POC technologies. Though the challenges of providing high-quality healthcare in developing countries are different than those in developed countries, there is a common goal to provide access to health monitoring and assessment technologies to people with limited or no healthcare facilities. While the developed countries may find POC technologies as effective means for reducing healthcare costs and improving efficiency, POC technologies are critical in responding to essential healthcare needs in countries with large populations or rural areas. The developing countries in the eastern part of the globe accounting for more than 2/3rd of the population of the world face the basic challenge of providing minimal healthcare to all people living in adverse geographical or economic constraints, and also monitoring critical diseases and infections such as HIV/AIDS, TB, malaria, etc. The challenge becomes even more critical in the situation of potential outbreak of an epidemic. The proposed conference will provide an international forum to explore POCT health monitoring technologies that could play significantly important role mode in “well-being” of a healthy society with increasing proportion of elderly people.

Advancements and approaches in developing MXene-based hybrid composites for improved supercapacitor electrodes

Zn/Fe-MOFs-derived hierarchical ball-in-ball ZnO/ZnFe2O4@carbon nanospheres with exceptional lithium storage performance

Background The rapid evolution of health monitoring technologies has transformed the landscape of chronic and preventive healthcare, with applications spanning diabetes, cardiovascular, and general health management. Continuous glucose monitoring systems, wearable electrocardiography (ECG), and mobile health applications provide real-time, accessible data to support early diagnosis, personalized treatment, and proactive patient engagement. This review aims to systematically examine current health monitoring technologies, their diagnostic accuracy, patient outcomes, and implementation challenges. Methods A systematic literature search of 55 peer-reviewed articles was conducted, focusing on diabetes and cardiovascular monitoring devices, general health trackers, and methodological approaches in health monitoring. Results Findings indicate that diabetes monitoring technologies, such as continuous glucose monitors, significantly improve glycemic control and reduce emergency hospitalizations. Cardiovascular health monitoring technologies, including wearable ECG and blood pressure devices, demonstrate potential in early detection and continuous risk assessment. General health monitoring tools, particularly fitness and wellness applications, show effectiveness in promoting preventive behaviors, though long-term efficacy remains uncertain. Common challenges identified include data security, integration into healthcare systems, and reliability across diverse populations. Conclusion This review underscores the strengths and limitations of these technologies and highlights the need for robust data management strategies and evidence-based integration into clinical practices. Future research should focus on enhancing interoperability, addressing privacy concerns, and evaluating outcomes across diverse populations to fully harness the potential of health monitoring technologies in clinical and community health settings.

Exercise-induced fatigue refers to the symptom that the body cannot continue to maintain the original training volume after a certain period of continuous training. Competitive aerobics athletes have a large amount of daily training exercise, and their bodies are prone to exercise fatigue. The health monitoring technology can monitor the physical state in real time and diagnose and treat the diseases caused by the body in time. This article aims at applying the health monitoring technology to the research of sports fatigue recovery of competitive aerobics athletes. This article first briefly introduces the theoretical review of exercise-induced fatigue, and it includes the definition, classification, and determination methods of exercise-induced fatigue, and then uses the health monitoring system to describe it, and finally conducts an experiment in the diagnosis and rehabilitation of exercise-induced fatigue. The health monitoring technology was compared with traditional medical methods, and the four aspects of speed, accuracy, recovery rate, and athlete's treatment satisfaction were tested. The experimental results show that the diagnostic accuracy based on health monitoring technology is the same as that of traditional manual medical diagnosis, reaching about 85%, which verifies its effectiveness.

2D transition metal carbides or nitrides (MXenes) have attracted considerable attention from materials scientists and engineers owing to their physicochemical properties. Currently, MXenes are synthesized from MAX-phase precursors using aqueous HF. Here, in order to enhance the production of MXenes, an anhydrous etching solution is proposed, consisting of dimethylsulfoxide as solvent with its high boiling point, NH4 HF2 as an etchant, CH3 SO3 H as an acid, and NH4 PF6 as an intercalant. The reaction temperature can be increased up to 100°C to accelerate the etching and delamination of Ti3 AlC2 MAX crystals; in addition, the destructive side reaction of the produced Ti3 C2 Tx MXene is suppressed in the etchant. Consequently, the etching reaction is completed in 4h at 100°C and produces high-quality monolayer Ti3 C2 Tx with an electrical conductivity of 8200 S cm-1 and yield of over 70%. The Ti3 C2 Tx MXene fabricated via this modified synthesis exhibits different surface structures and properties arising from more F-terminations than those of Ti3 C2 Tx synthesized in aqueous HF2 T. The atypical surface structure of Ti3 C2 Tx MXene results in an exceptionally high ultimate tensile strength (167 ± 8MPa), which is five times larger than those of Ti3 C2 Tx MXenes synthesized in aqueous HF solution (31.7 ± 7.8MPa).

2D transition metal carbides, nitrides, and carbonitrides, known as MXenes, were discovered in 2011 and have grown to prominence in energy storage, catalysis, electromagnetic interference shielding, wireless communications, electronic, sensors, and environmental and biomedical applications. In addition to their high electrical conductivity and electrochemically active behavior, MXenes' mechanical properties, flexibility, and strong adhesion properties play crucial roles in almost all of these growing applications. Although these properties prove to be critical in MXenes' impressive performance, the mechanical and tribological understanding of MXenes, as well as their relation to the synthesis process, is yet to be fully explored. Here, a fundamental overview of MXenes' mechanical and tribological properties is provided and the effects of MXenes' compositions, synthesis, and processing steps on these properties are discussed. Additionally, a critical perspective of the compositional control of MXenes for innovative structural, low-friction, and low-wear performance in current and upcoming applications of MXenes is provided. It is established here that the fundamental understanding of MXenes' mechanical and tribological behavior is essential for their quickly growing applications.

2D transition metal carbides and nitrides (MXene) are promising candidates for next-generation electrode materials due to their high electrical conductivity, large specific capacity/capacitance, and tunable surface chemistry. Nitrogen-doped MXene, in particular, have shown excellent electrochemical energy storage performance. However, the low and uneven nitrogen content has hindered both their performance and understanding of how N-terminal groups affect cation storage. This study successfully synthesizes N-terminated Ti3C2Nx via ion-exchange reactions in a hydrogen-containing argon atmosphere and investigates its energy storage behavior for H⁺, Li⁺, and Na⁺ ions. Ti3C2Nx shows outstanding H⁺ storage with a capacitance of 471 F g-1, while Li⁺ and Na⁺ storage exhibit a prominent intercalation mechanism. The Ti3C2Nx electrode delivers stable capacities of 209 mAh g-1 for Li⁺ and 79 mAh g-1 for Na⁺ after rate cycling, indicating good rate capability and reversibility. Combining density functional theory calculations with experimental data, this study reveals the correlations between adsorption energy, binding energy, and electronic density of states, highlighting the importance of real-gap distance in efficient cation intercalation, offering guidance for the design of MXene for H⁺, Li⁺, and Na⁺ storage.