Advanced Materials Technologies最新文献

Binders are important inactive materials for the performance and safety of lithium ion batteries (LIBs). Their identification from unknown cells or mixed recycling waste streams for teardown analysis or process control can be challenging. This study demonstrates an analytical approach using pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS), where characterization of these polymers is enabled by selective indicator pyrolyzates and where interfering matrix components are removed in a multishot pyrolysis. The binder materials styrene butadiene rubber (SBR), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA) and lithium polyacrylate (Li-PAA) are investigated in graphite (Gr)- and silicon nanowire (SiNW)-based electrodes at various stages of aging. A change of the CMC fingerprint is observed upon electrode processing, electrolyte contact, and electrochemical aging. Aging of the binder and superposition of polymeric solid electrolyte interphase (SEI) components is observed at 350 °C pyrolysis temperature. Washing experiments with dimethyl carbonate (DMC) are performed to differentiate between SEI- and binder-related pyrolyzates and to provide information on the aging condition of the electrodes. All binders show consistent fingerprints at 600 °C across all states of aging. This fingerprinting method improves the identification of polymers in battery recycling streams and provides insights into the thermal decomposition of negative electrode (NE) materials.

Organic electrochemical transistors (OECTs) are highly efficient ion-to-electron transducers, capable of achieving extremely large signal amplification, quantified by high transconductance (g_m) levels. Optimizing this parameters is crucial for developing highly sensitive electronic and bioelectronic devices. Here, record-high transconductances values exceeding 100 mS are obtained in vertical step-edge OECTs (vOECTs) utilizing two well-known p-type organic semiconductors: poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly(3-[2-[2-(2-methoxyethoxy)ethoxy]ethyl]thiophene-2,5-diyl) (P3MEEET). Both materials exhibit high on-currents, small hysteresis and an on/off ratio on the order of 10⁵. To benchmark the performance of vertical OECT architectures, it is proposed to normalize the maximum transconductance to the minimal footprint of the devices, which is equivalent to the cross-sectional area of the transistor channel defined by the product of channel width W and channel thickness d. By comparing g_m/(Wd), these devices achieve one of the highest values reported to date. This work demonstrate record transconductances in well-known materials using step-edge vOECTs with a small cross-sectional area, establishing a robust platform for high-performance OECT-based applications.

Reliable, long-term monitoring of health data is becoming increasingly essential in modern healthcare. While computational and machine learning capabilities continue to advance, the lack of lightweight, conformable, and customizable hardware remains a key limitation. In the context of heart health, traditional electrocardiogram (ECG) electrodes are rigid and often uncomfortable for continuous wear. Existing soft electrodes tend to be either cost-prohibitive or unreliable over extended use. In this work, all-polymer, 3D-printed, highly stable, and conformable ECG patches are developed for long-term signal acquisition. Through material optimization, composite materials with electrical conductivity up to 1.7 S cm⁻¹ are developed, maintaining over 85% of their conductivity after 60 days of exposure to open air. These materials also exhibit remarkable stretchability (strain at break up to 253%) and high mechanical strength (tensile strength of 25 MPa). The formulated inks are fully compatible with 3D material extrusion techniques, significantly reducing manufacturing costs. The printed electrodes are flexible, stretchable, and capable of recording high-quality ECG signals, performing comparably to state-of-the-art metal electrodes, even after more than a month of use-and-store in open air.

This study engineered a silicon-based neural probe integrating electrical stimulation and neural recording capabilities through microfabrication. Featuring a four-shank architecture, the probe enables locomotion control and olfactory recognition in locusts via single implantation: Outer shanks (2 mm × 80 µm) implanted at antennal bases deliver pulse width modulation (PWM) electrical pulses (2–5 V, 10–90% duty cycle) to modulate steering behavior, exhibiting linear correlations between voltage/duty cycle and turning angles with >85% success rates; inner shanks (150 µm width) with eight recording sites (28-µm diameter) decode odor-specific neural responses from 58 antennal lobe neurons—ammonium nitrate selectively activates N2/N4 neurons; benzaldehyde triggers N1/N5 responses; and 2-hexenal induces population burst firing—achieving 92.8% static recognition accuracy via quadratic discriminant analysis (QDA) classification. To address dynamic challenges, ΔRMS energy feature analysis is implemented, overcoming motion artifacts to maintain 84.8% odor recognition during locomotion at 50-ms resolution. Long-term validation confirmed stable 27-h operation: ΔRMS attenuation ≤16.7%, signal-to-noise ratio (SNR) attenuation 1.32 dB, steering success >85%, and odor recognition accuracy 80.1%, establishing a critical functional window for perception-control integration in biohybrid robotic systems. This probe successfully integrates insect motion control and odor discrimination, offering insights for developing multifunctional neural interfaces in insect hybrid robotics and advancing bio-robot technologies.

Appearing as one of the key-components of lithium-ion batteries (LIBs), this work specifically focuses on the additive manufacturing (AM) of custom-shape separators, facilitated by the filament material extrusion process, also called fused deposition modeling (FDM). The development and optimization of composite thermoplastic filament feedstocks combining polypropylene and paraffin wax, followed by the 3D printing of the separator membranes is shown. A post-processing step, based on thermal induced phase separation (TIPS), is introduced to promote porosity formation through removal of the paraffin wax sacrificial phase within the 3D printed items. Separators with different polypropylene/paraffin wax ratios are developed and the impact on printability, mechanical strength, porosity, and electrochemical performances, is thoroughly discussed. X-ray micro-computed tomography is employed to assess the geometric fidelity and to detect printing defects in a complex 3D lattice structure. The performance of the 3D printed porous separators is also compared to a commercial separator. This pioneering research establishes a foundation for the creation of porous separators that can adapt to and conform into 3D printed battery architectures with novel form factors, and also creates opportunities for the use of FDM and TIPS for a wide range of applications that employ porous structures beyond the energy storage field.

Glaucoma, the second leading cause of blindness globally, frequently results in irreversible vision loss. The unique anatomical structure and dynamic physiological characteristics of the human eye pose significant challenges for early diagnosis and therapeutic management of glaucoma. Smart intraocular pressure (IOP) sensors capable of continuous monitoring are critical for enabling real-time IOP tracking, a capability unattainable by conventional tonometry devices. However, to meet clinical ophthalmic requirements, sensor designs must prioritize continuous, non-invasive, high-precision, miniaturized, and high-transparency characteristics. Therefore, a comprehensive understanding of the fundamental principles and structural designs of diverse IOP sensors is essential. This review summarizes recent advances in IOP sensors by categorizing them into wearable and implantable devices. Their operating principles, structural designs, and sensing performance are systematically evaluated. Furthermore, the advantages and potential risks of these sensors are thoroughly analyzed to guide the development of next-generation IOP monitoring technologies.

Solar-driven interfacial evaporation (SDIE) for freshwater production is regarded as a sustainable and promising desalination technology capable of effectively addressing freshwater scarcity. Due to their high adaptability and synthetic modifiability, hydrogels can be optimized to meet the diverse requirements of efficient solar evaporators. Despite significant progress in the design and fabrication of hydrogel-based solar evaporators, there remains a lack of comprehensive summaries and reviews in this field. In this paper, recent advancements in hydrogel-based evaporators for solar-driven seawater desalination, ranging from material selection to structural design, are systematically reviewed. First, the unique state of water molecules is elucidated within hydrogels and discusses how altering their morphology and structure through fabrication methods can enhance water evaporation efficiency. Subsequently, the design principles of hydrogel-based solar evaporators, focusing on high light absorption performance, water transport capacity, heat management, regulation of evaporation enthalpy, utilization of environmental energy, and resistance to salt accumulation, are summarized. Finally, based on current findings and analyses, an overview of the research progress of hydrogel-based evaporators in seawater desalination and offer insights into their future development is provided.

The integration of flexible sensors and deep learning has significantly advanced human-machine interaction. However, developing high-resolution and cost-effective pressure sensor arrays (PSAs) remains a challenge. This study presents a PSA with a mortise-and-tenon interlocking structure, composed of four T-shaped capacitive pressure sensors (TCPSs). The TCPS is fabricated using low-cost commercial materials such as conductive polyurethane foam, polyester fabric, and polyimide film, and demonstrates region-specific sensitivity, rapid response time, and excellent stability. When assembled into a mortise-and-tenon interlocking sensor array (MTIPSA), the spatial resolution improves to over 200% of that of conventional designs. The MTIPSA excels in flexible interaction applications: as a flexible keyboard, it achieves 99.33% accuracy in classifying 30 types of inputs (letters and punctuation) using a convolutional neural network (CNN), and as a writing pad, it recognizes digits (0–9) with 99.25% accuracy. By integrating a CNN with a long short-term memory (LSTM) network enhanced by a self-attention mechanism (SAM), the system achieves 99.5% accuracy in identifying individual users from handwriting samples. This work has broad application prospects in smart electronic skin and human–machine interaction.

Biomedical Devices

There is a pressing need for vascular grafts in patients who cannot have bypass surgery because there are not suitable grafts made from their own body. In article number 2500077, Marcelo Muñoz, Emilio I. Alarcon, and co-workers develop a device that can make these grafts right on the spot. This could change bypass surgery forever, making it possible to do minimally invasive surgery

Directional liquid transport has garnered widespread attention due to its excellent performance in microfluidic manipulation, seawater desalination, and boiling heat transfer applications. The design of composite micro-nano biomimetic structures based on the unique features of natural biological systems has demonstrated extraordinary capabilities in liquid manipulation. The dynamics of liquid and interface interactions, as well as the liquid transport mechanisms of biological structures, enable controllable liquid transport, showing tremendous potential in the field of heat and mass transfer. Understanding these mechanisms is essential for effective structural design in heat and mass transfer. This review summarizes the recent research advancements on the liquid transport mechanisms of wetting interfaces and their applications in the field of heat and mass transfer. First, it presents the fundamental principles of interfacial fluid dynamics. Next, it elucidates the innovative design principles of biomimetic structures and their excellent liquid transport performance. Then, it discusses the applications of directional liquid transport in heat and mass transfer. Finally, it shares insights into challenges and future directions in fluid dynamics and heat and mass transfer applications for wet interfaces.