Advanced Materials Technologies最新文献

Force-Sensitive Microfluidic Cantilevers

This image presents a novel method for cryoEM sample preparation using a force-sensitive microfluidic AFM cantilever. It enables femtolitre-scale extraction of subcellular material from individual cells and precise dispensing onto cryoEM grids. The technique allows high-resolution imaging of biological structures in native context, addressing limitations of conventional methods and offering new possibilities for cellular ultrastructure studies. More information can be found in the Research Article by Arjen J. Jakobi, Murali Krishna Ghatkesar, Andreas Engel, and co-workers (10.1002/admt.202501333).

Nonadherence to prescribed medication regimens continues to pose a significant challenge in healthcare, highlighting the need for precise, user-friendly, and personalized drug-delivery systems. Transdermal drug delivery (TDD) using microneedle arrays (MNs) is a minimally invasive and patient-compliant alternative to conventional methods. However, traditional designs are hindered by their limited drug loading capacity, passive release mechanisms, and complex fabrication processes. In this study, we present a wearable TDD platform that integrates hollow-groove microneedles (HGMNs) with a wirelessly controlled, electronically programmable micropump for precise, on-demand liquid-phase drug administration. HGMNs, produced via digital light processing (DLP) 3D printing, feature engineered grooves to enhance drug transport and prevent tissue blockage. The system includes a refillable spiral microfluidic reservoir and a compact micropump capable of delivering customized dosing regimens, such as single-bolus, pulsatile, and sustained-release profiles. Utilizing ketamine hydrochloride as a model drug for post-traumatic stress disorder (PTSD), the platform demonstrated robust skin penetration, high delivery precision, and effective diffusion through the ex vivo porcine skin. Mechanical testing confirmed the structural integrity and force threshold required for skin insertion. This versatile platform facilitates programmable, noninvasive, and accurate drug administration, offering the potential to enhance treatment outcomes, improve patient adherence, and support personalized medicine.

Wireless power transfer (WPT) technologies enable the remote transmission of electric charges without galvanic connections, offering promising applications in biomedical and environmental fields. Recent advancements in ultrasound-driven triboelectric nanogenerators (US-TENGs) address key technical challenges such as safety, deep penetration, compatibility, and tunability, enabling efficient electricity generation within biological tissues and fluidic environments. The emergence of US-TENGs represents a pivotal advancement in WPT, particularly for powering rechargeable implantable bioelectronic systems, as well as battery-free and self-powered devices for biotherapy, and underwater energy transfer and communications. This review discusses the potential of US-TENGs to enhance wireless energy harvesting in medical and environmental fields, emphasizing their integration and design with booster, flexible, biocompatible, and biodegradable materials to develop mechanically adaptive, efficient, stable, and minimally invasive systems. Roadmaps for various energy transfer applications of US-TENGs are presented to show recent progress. Finally, the necessary developments for the classified functionalities are discussed to address remaining challenges.

Formaldehyde Chemiresistors

In their Research Article (10.1002/admt.202501495), Meng-Fang Lin and co-workers detect formaldehyde, a hazardous indoor pollutant and carcinogen, at room temperature (1–35 ppm) using a CeO₂-decorated PANI nanohybrid. Combining 1D nanofibers and 2D nanosheets with UV-light activation enhances sensitivity, selectivity, and humidity tolerance, even under interfering gases. This advancement offers a practical strategy for real-world environmental monitoring and public health protection.

Self-Healing Polyimide

This cover image describes a self-healing polyimide developed for flexible electronics. It highlights reversible dynamic disulfide bonds and siloxane-containing aliphatic chains allowing rapid surface repair via Joule heating. The balance of rigid and flexible segments in the backbone allows tunable mechanical properties. The illustration emphasizes the potential of the material for durable and flexible electronic devices. More information can be found in the Research Article by Heung Cho Ko, Nam-Ho You, and co-workers (10.1002/admt.202500834).

Micro-light-emitting diodes (micro-LEDs) are highly promising for next-generation transparent displays owing to their exceptional brightness, fast response time, and environmental stability. However, conventional active-matrix (AM) driving schemes based on thin-film transistors (TFTs) and capacitors suffer from limited optical transmittance, scalability challenges, and complex fabrication. Here, a novel AM driving architecture is proposed, incorporating vertically stacked transparent memristor (T-MEMTs) to drive transparent micro-LEDs. The T-MEMT, composed of an ITO/TiO₂/HfO₂/ITO structure, exhibits 17 stable multilevel resistance states and excellent switching endurance, enabling precise brightness modulation without the need for external capacitors. Owing to its high optical transmittance (>85% in the visible range) and simple two-terminal configuration, the T-MEMT is monolithically integrated on top of micro-LEDs, significantly enhancing the integration density compared to TFT-based counterparts. To demonstrate the feasibility of the proposed AM scheme, an 8 × 8 transparent micro-LED array is fabricated via direct line deposition without transfer or bonding processes, successfully displaying static characters (“A”, “S”, and “L”) and dynamic grayscale images by AM operation of T-MEMTs. This work offers a highly integrated, transparent, and scalable AM display platform suitable for applications in augmented/virtual reality, automotive head-up displays, and smart window technologies.

Electrochromic materials, prized for their energy efficiency and environmental adaptability, have drawn significant research attention toward energy conservation and sustainability. Conversely, traditional photocured gels face challenges such as high equipment requirements, toxic photoinitiators, and intricate preparation processes. In response, this research develops a facile method for preparing photocured conductive hydrogels, employing tungsten trioxide (WO₃) and molybdenum trioxide (MoO₃) as non-toxic photoinitiators, such as reliance on UV equipment and toxic photoinitiators. WO₃ and MoO₃ synergistically enhance the photo-response and curing speed, enabling rapid solidification into a conductive hydrogel under sunlight within 3 min. The resulting hydrogel demonstrates remarkable mechanical properties, including 400% elongation, self-healing capabilities (restored conductivity within 5 min), and good water–retention, showcasing excellent performance in flexible electrochromic devices and stress sensors. The present study delves into the gel's curing mechanism, electrical and mechanical properties, and self-healing capability, inspiring future applications in electronic devices, flexible circuits, and smart materials.

Aerosol jet printing is an emerging technology for printed electronics, offering high-resolution, noncontact deposition on complex surfaces with broad material compatibility. However, process variability remains a critical challenge in aerosol jet printing, limiting its broader adoption for industrial applications. In this work, a multiparameter closed-loop control framework is developed and validated that significantly improves process stability over extended print durations. In situ light scattering measurements are used to monitor aerosol volume fraction in real time and serve as the feedback signal for two independently tuned parallel control loops. Dynamic response testing reveals the temporal characteristics of each control parameter, enabling the design of targeted control strategies. A slow response loop modulates atomizer voltage to suppress long-term drift in atomization, while a fast response loop adjusts carrier gas flow rate or feed rate to reduce short-term variability. Compared to open-loop printing, the multiparameter control approach reduces the relative standard deviation of electrical conductance in printed samples from 42% to 5% and reduces drift from 25% h⁻¹ to 3% h⁻¹ over a three hour print. This work advances process control in aerosol jet printing systems and demonstrates a strategy for improving manufacturing reliability for printed electronics.

Vapor phase deposition processes for the fabrication of perovskite solar cells show great potential for transferring from laboratory-scale to continuous industrial-scale production. Precise process control and high process reproducibility are of utmost importance to unlock their full potential. In this regard, the sublimation behavior and rate control of organic precursor materials in thermal evaporation processes are particularly challenging. Here, it is investigated in detail how the particle size of formamidinium iodide (FAI) and the crucible geometry influence the directionality of the emitted vapor flux. It is shown that conical crucibles lead to beam focusing of the vapor flux, while cylindrical crucibles show a broader, less directional emission profile. This leads to differences in the homogeneity of material deposition depending on the lateral source-to-substrate distance. Furthermore, there is a substantial impact of FAI particle size on the directionality of the vapor flux for conical crucibles, affecting the deposited material thickness gradient over the substrate. Analyzing commonly employed inorganic materials reveals the strong material dependence of effusion characteristics, leading to additional complexity for multi-material deposition processes. The findings emphasize that both homogenization of organic precursor materials and optimization of source geometry and arrangement are critical for achieving uniform deposition and, consequently, improved process reproducibility.

For over a decade, additive manufacturing (AM) has experienced several hype cycles from the academic and industry worlds. Although not every forecast turned into reality, it is consensual that AM is key to shifting from machine-dominated to digital productions. AM promotes decreased supply chain complexity by commissioning on-site and on-demand customized components, faster response to customer demand, and enhanced sustainability. Currently, metal- and polymer-based AM is widely accepted, considering the variety of international standards issued (ASTM and ISO), their applications, and strategic foresight opportunities. Advanced ceramic AM, conversely, is only now getting widespread attention from scientific institutes, start-ups, and industries. Ceramic materials’ inherent brittle nature, defect-sensitive properties, and extensive post-processing are major blockers in exploiting ceramic best traits. Fortunately, ceramic AM has shown leverage in solving ceramic formability bottlenecks. In this review, the up-to-date traditional manufacturing interrelationship with AM is discussed in scope of ceramic aerospace and defense applications. Applications of advanced ceramics in such areas encompass thermal protection systems, thermal barrier coatings, armor and space shielding, sensors and actuators. The synergy between AM and Industry 4.0 technological pillars (digital twins, cloud computing, the IoT, augmented reality, big data analytics, artificial intelligence, and machine learning) is also presented and discussed.