Advanced Materials Technologies最新文献

Physiological temperature sensors are essential for accurately tracking body temperature, yet human body temperature sensors with both high precision and linearity have not been widely reported. In this work, a solution-processed, low-voltage TFT-based temperature sensor is developed using LiInSnO₄ ionic gate dielectric with ZnO (or SnO₂) as semiconductors. Alongside excellent TFT performance, the devices exhibit high precision and sensitivity of 0.7 µA °C⁻¹ during heating and 0.6 µA °C⁻¹ during cooling for ZnO-based TFT, while SnO₂-based TFT shows slightly higher sensitivity with 1.1 µA °C⁻¹ in heating and 1.2 µA °C⁻¹ in cooling. Additionally, the voltage sensitivity remains consistent at 0.01 V °C⁻¹ for both TFTs under all conditions. Furthermore, the devices demonstrate high linearity in temperature coefficient of current (TCC) and temperature coefficient of voltage (TCV) curves, confirming their capability for accurate temperature measurement.

Physiological temperature sensors are essential for accurately tracking body temperature, yet human body temperature sensors with both high precision and linearity have not been widely reported. In this work, a solution-processed, low-voltage TFT-based temperature sensor is developed using LiInSnO₄ ionic gate dielectric with ZnO (or SnO₂) as semiconductors. Alongside excellent TFT performance, the devices exhibit high precision and sensitivity of 0.7 µA °C⁻¹ during heating and 0.6 µA °C⁻¹ during cooling for ZnO-based TFT, while SnO₂-based TFT shows slightly higher sensitivity with 1.1 µA °C⁻¹ in heating and 1.2 µA °C⁻¹ in cooling. Additionally, the voltage sensitivity remains consistent at 0.01 V °C⁻¹ for both TFTs under all conditions. Furthermore, the devices demonstrate high linearity in temperature coefficient of current (TCC) and temperature coefficient of voltage (TCV) curves, confirming their capability for accurate temperature measurement.

Inorganic oxide-based perovskites are recognized as efficient switching materials due to their oxygen anionic conduction, high dielectric constant, and ambient stability. However, their rigid crystal structure limits use in flexible electronics. This study presents a fully flexible crossbar memristor array using hybrid ink of inorganic BaTiO₃ (BTO) nanoparticles and organic polymer polyvinyl alcohol (PVA) in a 1:15 wt% ratio. The 6 × 6 memristor array was fabricated on indium tin oxide (ITO)-coated polyethylene terephthalate substrate, where the ITO bottom electrode was patterned by photolithography, followed by screen printing of the BTO–PVA layer and nickel top electrode deposition via sputtering. The devices showed stable bipolar resistive switching with low SET/RESET voltages (1.70 V/–1.75 V), high ON/OFF ratio (~10⁴), excellent endurance (〉10⁶ s), and minimal variability. Mechanical robustness was tested by bending to radii of 19.1 mm, 9.5 mm, and 6.4 mm; ON/OFF ratio stayed ~10⁴, SET/RESET voltages shifted ≤26%, with slight current-noise increase (maximum standard deviation of 1.29 at 〈0.3 V). Switching was trap-controlled: BTO provided traps, PVA enabled hopping transport, flexibility, and high resistance states. Conductance-based color mapping of a bent 6 × 6 array confirmed reliable switching, supporting BTO–PVA hybrid ink as a robust, flexible memory platform.

The geometric appearance of weld is very important for the evaluations of welded joint performance and weld quality during oscillating laser welding (OLW). To represent the characteristics of weld appearance more accurately, the surface reconstruction method is often adopted to obtain the complete geometric appearance of weld. The efficiency of surface reconstruction method is crucial for practical application, especially for processing large-scale point cloud. An improved octree-based surface reconstruction method is proposed to enhance the computational efficiency for complex weld appearance based on the point cloud. The large-scale point cloud of weld which is transformed from numerical simulation of OLW is preprocessed by octree structure to reduce the number of points and the Poisson surface reconstruction (PSR) method is utilized to reconstruct the three-dimensional profile of weld appearance. The reconstruction accuracy is quantified by contrasting the cloud-to-mesh distances between the raw point cloud and the reconstructed mesh model. Furthermore, the reconstruction efficiency and accuracy of the proposed method are compared with those of PSR method and the reconstruction quality of proposed method with octree structure is compared with those of methods with other sampling strategies. The results demonstrate that the reconstruction efficiency of the proposed method is significantly increased with excellent reconstruction accuracy. The improved octree-based surface reconstruction method is of great importance for analyzing weld appearance characteristics and evaluating weld quality.

Nanocomposite-Based Pressure Sensors

In their Research Article (10.1002/admt.202501316), Hamed Arami, Layla Khalifehzadeh, and co-workers report an ultrasensitive wireless capacitive pressure sensor for health monitoring. Using ZnO nanocomposite microstructures, the device achieves a 4.3-fold sensitivity enhancement. A novel wireless setup enables long-range pressure monitoring. In vivo studies demonstrate reliable detection of subtle brain pressure variations.

To eliminate the thermal impact on oxide semiconductor channels during the device integration, a novel stacking strategy is explored for 3D integration of oxide thin-film transistors (TFTs). In this configuration, lower-layer planar-channel TFT (PTFT) and upper-layer vertical-channel TFTs (VTFTs) are designed in a vertical-stacking arrangement with an inter-electrode dielectric (IED) and a single active layer. This novel configuration is termed single-active-stacked TFT (SAS-TFT). The choice of IED is identified as an important factor for the operational functionality of the bottom PTFT. The PTFT using an Al₂O₃ IED demonstrates superior device performance in comparison to that using an SiO₂ IED. The disparities in process conditions between two IEDs are responsible for more severe process damage to the back-channel interface and source/drain electrodes of the PTFT using an SiO₂ IED, attributable to the creation of additional defect states in the channel and the increase in contact resistance. Alternatively, the top VTFTs arranged in the SAS-TFT employing an Al₂O₃ IED exhibit sound device operations without any marked device-stacking process damage. The top VTFT demonstrates a high current drivability of 26.8 µA µm^‒1 and an on/off current ratio of 10¹⁰. The SAS-TFT is a successful innovation achieved through the exploration of optimal process conditions.

Electromagnetic Wave Absorbing Structures

This cover illustrates a bioinspired metamaterial absorber based on porous silicon carbide. By adjusting the interlayer angle and other structural parameters, the absorber enables enhanced electromagnetic wave attenuation through improved impedance matching and energy dissipation. The design offers reconfigurable absorption characteristics, making it suitable for broadband and adaptive electromagnetic absorption applications. More details can be found in the Research Article by Lu Feng, Wanchong Li, Jinsong Zhang, and co-workers (10.1002/admt.202500831).

Optofluidic Oscillators

In their Research article (10.1002/admt.202500910), Jing Zeng, Wen Fan, and co-workers utilize smartphone-assisted high-speed microscopy (up to 7680 fps) to visualize the self-sustained oscillations of EGaIn microdroplets partially immersed in HCl. The asymmetric cycles involve rapid oxidation-driven contractions followed by slower recovery mediated by acid-induced oxide dissolution. Janus EGaIn–HCl droplets autonomously modulate laser reflections and interference patterns, enabling programmable optofluidics and adaptive photonics.

Accurate ocean flow velocity monitoring is crucial for marine engineering and environmental sensing but faces challenges under low-flow conditions due to limited energy, power integration difficulties, and reduced sensor sensitivity. To overcome these, this work introduces a novel underwater cylinder-enhanced flag-shaped triboelectric nanogenerator (UCF-TENG). It utilizes vortex-induced vibrations (VIV) from an upstream bluff body for efficient flow detection. Based on a quantified Strouhal number relationship, the UCF-TENG provides a direct, linear mapping between flow velocity and output signal frequency. Experimental results demonstrate that the UCF-TENG achieves a startup flow velocity as low as 0.211 m·s⁻¹ and a peak output voltage of 1.81 V. Across the tested velocity range, the output signal frequency maintains a strong linear correlation with flow velocity (R² = 0.9893), indicating excellent sensitivity under low-flow conditions. Furthermore, fluid-structure interaction (FSI) simulations conducted in ANSYS Fluent validate the underlying VIV-driven signal generation mechanism and provide theoretical support consistent with experimental observations. This work offers a compelling solution for real-time, energy-autonomous flow sensing in resource-constrained marine environments and holds application prospects in intelligent marine systems.

Capillary blood sampling plays a crucial role in diagnostic decentralization, yet most microsampling devices remain expensive, limiting their use mainly to developed countries. To improve accessibility, a cost-effective silicone device capable of extracting small volumes of capillary blood in vivo was previoulsy developed by our group. However, the use of non-degradable materials poses limitations, especially in resource-limited settings with inadequate waste disposal infrastructure. Herein, a nearly fully degradable microsampling prototype is reported. The device body is fabricated using digital light processing 3D printing with tailored poly(ɛ-caprolactone-co-D,L-lactide). This device yields negative pressure and adhesion strength comparable to the original prototype, although it requires greater manual compression. In vitro, it collects ≈670 µL of porcine whole blood, matching the volume drawn by the silicone counterpart. The device is equipped with magnesium microneedle blades coated with poly(ɛ-caprolactone) to enhance blood stability. Degradation studies show complete disintegration of poly(ɛ-caprolactone-co-D,L-lactide) under composting conditions within 60 days, and near-complete degradation of magnesium blades in aqueous buffer within 40 days. Preliminary hemolysis assays confirm blood compatibility of both the 3D-printed device and coated microneedles, with sample quality preserved for up to 3 h. Altogether, these findings highlight the potential of this degradable prototype as a sustainable alternative for capillary blood collection.