Advanced Materials Technologies最新文献

Smart Wearable Electronic Textiles

In the field of smart wearable electronic textiles, the integration of soft actuators is gaining significant recognition for their distinct advantages. In article number 2400079, Bao Yang and co-workers show that by seamlessly integrating with textiles, these actuators empower textiles to accurately detect and respond to diverse stimuli. This study timely reviews recent advancements, offering a systematic overview of key strategies and hurdles in optimizing actuator functionality.

Resonance Rayleigh Scattering

Accurate monitoring of neurotransmitters and precise characterization of the secretory ability of neurons are essential for effective treatment of neurological diseases. In article number 2301701, Mohamad Sawan and co-workers discover that the binding of small neurotransmitters to aptamers induces a conformational change that alters the effective radius of Au nanoclusters-aptamer complexes. This change can be detected in the resonance Rayleigh scattering intensity.

Surface-Level Muscle Deformation

In article number 2400444, Jonathan T. Alvarez, Conor J. Walsh, and co-workers introduce a non-contact method using a 2D laser profilometer to measure surface-level muscle deformation, a promising signal for estimating joint torque. The findings demonstrate strong correlations between deformation metrics—peak radial displacement, surface curvature, and surface strain—and volitional elbow torque across varying measurement locations and joint angles. This methodology standardizes evaluations, informing future wearable sensor design.

Fiber-Chip Edge Couplers

In article number 2400196, Xingchen Ji, Yikai Su, and co-workers introduce a high-efficiency edge coupler based on an alumina-on-insulator platform, which consists of a symmetric double-tip taper and a multimode interference (MMI)-based optical combiner. The edge coupler is designed to realize efficient mode matching between the single-mode fiber and chip facet via the symmetric double-tip taper at the initial stage, and then combine the two channels in the taper into a highly confined strip waveguide through the MMI-based combiner.

Electrolytic capacitors are known to be fast devices with very low time constant and able to deliver high power. This class of capacitors is then an interesting technology to power miniaturized embedded electronics for Internet of Things applications. However, the current electrolytic capacitor suffers from its bulky size that does not fit with the miniaturization. To solve this issue, a proof-of-concept consisting of miniaturizing an electrolytic capacitor based on tantalum materials to give rise to a new class of electrolytic micro-capacitors is proposed. To reach this ambitious objective, thin films (<100 nm) of tantalum metal (Ta), tantalum nitride (TaN), and tantalum oxide (Ta₂O₅) are deposited on a Si substrate by sputtering deposition method. After a careful optimization of the deposition parameters, Ta/Ta₂O₅ and TaN/Ta₂O₅ electrodes (Ta and TaN ≈45 nm and Ta₂O₅ ≈25 nm) and study their behaviors when biased at high voltage (>20 Volts) in aqueous electrolyte are produced. The Ta/Ta₂O₅ and TaN/Ta₂O₅ interfaces when the electrode is polarized near and beyond the breakdown voltage of the dielectric layer are carefully investigated. Polarizing the electrodes beyond the breakdown voltage are shown to result in anodization-like mechanisms. In the case of the TaN/Ta₂O₅ electrode, an N-rich porous layer grew within the Ta₂O₅ layer as polarization increased. A comparative study on the 2 stacked layers electrodes with different compositions (Ta/Ta₂O₅ and TaN/Ta₂O₅) but similar thicknesses (45/25 nm) is carried out: both electrodes show excellent capacitance retention of over 90% over 300 000 cycles. The frequency behavior of Ta/Ta₂O₅ and TaN/Ta₂O₅ electrodes shows that both are potential candidates in electrolytic micro-capacitors for powering miniaturized electronics.

Supercapacitors (SCs) have the unique ability to rapidly recharge while providing substantial power output. Metal-organic frameworks (MOFs) are emerging as promising electrode materials for SCs due to their high porosity, ease of synthesis, tunable pore size distribution, and exceptional structural adaptability. This study presents a facile and cost-effective method, namely, laser ablation synthesis in solution (LASiS), for the synthesis of bimetallic MOFs composited with reduced graphene oxide (rGO), namely, ZnCo bi-MOF-rGO hybrid nanocomposite (HNC). Comprehensive analyses demonstrate that ZnCo bi-MOF-rGO has a high specific capacitance of 1092 F g⁻¹ at 1.0 A g⁻¹ in a 0.5 M Na₃SO₄ electrolyte. In addition, these bi-MOF-rGO composites have been successfully integrated with appropriate solvents, viscosity modifiers, in-house synthesized porous carbon (PC), commercially available graphene, and binders into an active layer ink material for the development of high-performance 3D printed SCs via sequential inkjet printing. To that end, the way has been paved for the incorporation of this class of material into energy storage applications, particularly in the fabrication of high-performance printed electronics using laser-induced materials.

Implantable electrical neurostimulators offer a promising avenue for treating neurological disorders. However, their dependency on a finite battery life limits their long-term utility. Emerging transcutaneous ultrasound-driven triboelectric nanogenerator (TENG) techniques provide solutions for converting external ultrasound waves into internal electricity. This study proposes an implantable ultrasound-driven TENG (IU-TENG) using polyether ether ketone (PEEK) for its exceptional stability inside a human body and acoustic impedance compatibility with human tissues. This IU-TENG remarkably surpasses traditional titanium-based encapsulation, resulting in a 99.94% efficiency in ultrasound transmission. In addition, PEEK contains numerous electron-donating functional groups, making it suitable for TENG applications, particularly as a positive triboelectric layer. The device exhibits robust voltage outputs, reaching up to 11.50 and 8.75 V in water and in vivo, respectively, under body-safe ultrasound intensities. Moreover, its ability to sustain a stable electrical output for over 300 min emphasizes the durability and mechanical resilience of PEEK. In vivo mouse models and ex vivo porcine tissue trials demonstrate the effectiveness of the IU-TENG in nerve stimulation, showing its potential in medical treatments, enhancing the functionality and longevity of implantable medical devices.

Modern sensing technologies are highly required for health monitoring. In this respect, the development of small-size, high-performance, and self-powered biosensors for detecting and quantifying disease markers in biofluids can bring crucial changes and improvements to the concept of health monitoring systems. Clinical trials identify a wide range of biomarkers in biofluids that provide significant health information. Research into novel functional materials with outstanding properties opens up new perspectives for fabricating new-generation biosensors. Furthermore, energy conversion and storage units are investigated to integrate them into biosensors and develop self-powered systems. Electrochemical methods are very attractive for applications in biosensor technology, both in terms of biomarker detection and energy generation. Here the recent achievements in research into self-powered electrochemical biosensors to detect sweat and saliva biomarkers are presented. Potential biomarkers for efficient analysis of these fluids are discussed in light of their importance in identifying various diseases. The influence of electrode materials on the performance of sensors is discussed. Progress in developing operating strategies for self-powered electrochemical monitoring systems is also discussed. A summary and outlook are presented, mentioning major achievements and current issues to be explored.

Stretchable Thermoelectric Devices

In article number 2301171, Joonbum Bae and Hayeon Kim present a stretchable thermoelectric device designed to improve heating and cooling performance. The device utilizes direct ink writing for precise liquid metal deposition and features a double-layer structure with an air gap. This configuration enables enhanced stretchability and facilitates twisting motion.