Advanced Materials Technologies最新文献

Magnetic microrobots are controlled to exhibit a wide range of motions, allowing them to navigate complex environments and perform multifunctional tasks with high precision. This work presents a novel hybrid electromagnetic actuation system by integrating two distinct conventional configurations, such as a paired-coils electromagnetic disc (EMD) system and a distributed electromagnetic array coil (EAC) system. In order to ensure the effective functioning of the microrobot, its motion dynamics are thoroughly analyzed to identify the critical kinetic parameters. For demonstration purposes, first, a mixing task is performed by employing a single microrobot actuated with simultaneous motions. The mixing efficiency is observed to reach 83% within 30 s, in contrast to the efficiency of control of 45%. Second, a structural reconfiguration function is demonstrated by employing an independent control of two U-shaped microrobots to form a new I-shaped microrobot. Last, differentiated motion control of multiple magnetic pads is demonstrated, resulting in various 2D static formations in the shapes of numbers and alphabets. The presented results hold great promise for advancing the field of microrobotics by offering a novel solution for versatile microrobot motion controls.

Advances in additive manufacturing technologies have enabled the fabrication of intricate bioscaffolds with tailored geometry, porosity, and material composition, offering new possibilities in biomedical engineering, drug screening, and cell scaffold applications. This study introduces a novel printable flexible soft ceramic material prepared by a combination of silica sol–gel processing and crosslinking of a dissolvable polyvinyl-trimesic acid polymeric network. The material's printability is showcased by creating 3D 90° grid scaffolds using an in-house extrusion-based printer, demonstrating a flexible response to compressive stress with minimal deformation over multiple cycles. Supercritical extraction and drying transform the printed structure into a highly porous, ultralow-density scaffold for cell culture. The MDCK cells cultured within the 3D biocompatible ceramic scaffold exhibit uniform growth and proliferation, maintaining viability for up to 35 days. When exposed to the environmental toxin, mercury, MDCK cells in a 2D culture show susceptibility at a low lethal concentration (0.075 mg·L⁻¹), while the 3D cell culture displays enhanced tolerance (4.0 mg·L⁻¹). It emphasizes the significance of the 3D microenvironment in mimicking physiological conditions more accurately, enabling a more precise assessment of environmental toxicants.

3D Printed Cellular Fluidics

Cellular fluidic devices take advantage of 3D printing, unit cell-based design, and fluid physics to realize hierarchical composite structures with complex geometries. In article number 2400104, Erika J. Fong and co-workers present a lattice-based hand model that uses varying porosity to pattern red liquid in the “skeletal” region, while the high porosity cells remained unfilled.

3D Printed Supercapacitors

In article number 2400151, Bamin Khomami and co-workers show that synthesizing and combining ZnCo bi-MOFs with rGO nanosheets during the laser ablation synthesis in solution (LASiS) process yields extremely porous and electrically conductive hybrid nanocomposites (HNCs) that can serve as high-performance supercapacitor (SC) material. This material is in turn used in sequential additive manufacturing to 3D print SC devices using ZnCo bi-MOF-rGO electrodes via inkjet printing.

Artificial tactile sensing capable of measuring shear and normal forces is crucial for the diverse human-machine interactions and dexterous robotic manipulations. However, existing soft multi-axis force sensors usually suffer from limited detectable directions and complex coupling mechanisms, limiting their applications in realistic wearable and robotic systems. Here, a hierarchically-interlocked, three-axis soft iontronic sensor is presented with an asymmetrical electrode pattern that leverages the mortise-and-tenon structure and ultracapacitive principle to detect omnidirectional shear and normal forces. The designed sensor facilitates the decoupling process and achieves enhanced sensing performances including high accuracy, fast response ability, and mechanical robustness. Prototypical integration and application of the sensor are demonstrated to perform wearable telecontrol of virtual platforms and assist robot gripper through closed-loop force feedback. A sensing array is further developed to construct a touch panel and identify handwriting based on the continuously measured directions of applied forces. This work may offer a potentially promising solution for the next-generation intelligent electronic skins requiring multimodal tactile sensing information.

Herein, the synthesis of a novel microencapsulated phase change material via a sol–gel method is presented, featuring disodium hydrogen phosphate dodecahydrate as the core and a SiO₂/graphene oxide composite as the shell. The morphology and core–shell microstructure of the synthesized microcapsules are characterized using scanning electron microscopy. The phase change performance and thermal stability are evaluated by differential scanning calorimetry and a high/low temperature test chamber, respectively. Energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy are employed to determine the chemical composition of the microcapsules. The findings reveal that the MEPCM exhibited a high melting enthalpy of 174.3 J g⁻¹. The degree of supercooling is reduced by 2.1 °C, and after 600 thermal cycles, the phase change enthalpy of the microcapsules showed a minor decrease of ≈6.0%. Notably, the thermal conductivity of the microcapsules is significantly enhanced, increasing by up to 51.8%. When integrated into the thermal management systems of lithium-ion batteries, the MEPCM effectively maintained the battery temperature below 46 °C under a 3 C charging rate. In summary, these results suggest that the hydrated salt microcapsule with its hybrid silica and graphene oxide shell is a promising material for the thermal management of lithium-ion batteries.

Artificial sub-microfluidic and nanofluidic devices allow for studying mass or ion transport effects under spatial confinement. It remains challenging to fabricate large-scale, nanofluidic channels of well-defined thickness for fundamental studies and practical applications, especially for extreme confinement conditions (e.g., with sub-10 nm channel height). Here, a strategy is reported to fabricate large-scale nano-channels with the channel height down to 5.0 nm. The fabrication is enabled by developing ultra-flat and ultra-thin polymethylmethaacrylate (PMMA) layers as the spacer. The ease of scaling up the channel length to a millimeter in the lateral dimensions with high mechanical stability is demonstrated. Furthermore, experimental evidence is provided of the role of the mechanical coupling between the spacer and capping materials in determining the device's mechanical properties, and how controlling the channel width and the top graphite thickness can be employed to tailor the device's mechanical properties. Finally, employing near-field IR experiments, the decay constant is established for the near-field absorption intensity of PMMA molecules inside the channel by increasing the top layer thickness. This work develops a novel method for fabricating large-area, mechanically stable nano-channels for nanofluidic devices and lays the foundation for further in situ spectroscopic studies of electrochemistry within sub-10 nm confinement.

Benzonitrile derivatives (BDs) are very promising for applications in materials science, photonics, and optoelectronics due to their intriguing electronic and optical properties. This study comprehensively investigates BDs, aiming to uncover their fundamental characteristics and potential applications. Using advanced theoretical techniques like Gaussian software, it is gained unprecedented insights into the photoinduced isomerization phenomenon for all-optical switching in these compounds. The theoretical framework clarifies molecular transition states and explores a range of properties, providing a comprehensive understanding of BDs. Empirical data on the emission properties of BDs, from fluorescence analyses in liquid solutions to light amplification in solid-state PMMA thin films, complement the theoretical examinations. Notably, white light emission from a single benzonitrile compound is achieved, showcasing its potential for data transmission through Li-Fi technology. Finally, the all-optical switching phenomenon in BDs using 3rd order nonlinear optical effects is experimentally validated. This complementary and comprehensive study advances understanding of BDs and demonstrates their potential for practical applications in emerging photonic and optoelectronic technologies.

Light-Emitting Electrochemical Transistors

The cover image illustrates the integration of polyelectrolytes in light-emitting electrochemical transistors (LECTs), showcasing their multifunctional capabilities in electrochemistry and optoelectronics. In article number 2302207, Bright Walker, Han-Ki Kim, Jung Hwa Seo, and co-workers present LECTs that feature a streamlined device architecture enabled by electrochemical doping using poly(9-vinylcarbazole) doped with lithium ions (Li⁺) and copper (II) ions (Cu²⁺). The synergistic effects of these hybrid polyelectrolytes markedly enhance electron-hole recombination efficiency, resulting in bright and efficient electroluminescence.