Advanced Materials Technologies最新文献

The demand for wearable display devices capable of real-time information collection is growing rapidly. Among them, electrophoretic display (EPD) shows features of ultra-low power consumption and high readability in sunlight, making them particularly suitable for wearable applications. However, due to high driving voltage and susceptibility to salt, few wearable EPD devices are reported so far. To address this, a stretchable EPD compatible with textiles is fabricated based on waterborne polyurethane. The device exhibits great performance to resist water and sweat, achieving a whiteness of 35 (Y in CIE XYZ) and a contrast ratio of 13.5 at a driving voltage of 30 V. Benefit from the device's excellent bistability and flexibility, there is no degrading to its optoelectronic performance after bending, twisting or stretching. For demonstration, an 8 × 8 matrix display is realized, showcasing that this process is suitable for wearable textile display applications.

Flexible Grippers

In article number 2302126 by introducing giant electrorheological (BTRU) functional particles into dielectric elastomers, Jinbo Wu and co-workers show that the elastomers simultaneously possess both electro-induced variable stiffness variation and actuation functions, achieving a “killing two birds with one stone” effect. Utilizing advanced variable stiffness artificial materials and robotic technology to enable robots to express emotions like humans, achieving a modern presentation of traditional calligraphy art.

The rapid development of aircraft in recent years has attracted more attention, especially the issue of safe flight for aircraft. Some existing angle detection sensors are difficult to adapt to the development speed of the current aircraft due to the expensive price and large size, so there is an immediate need for new technology that can suit the current aircraft. Here, a self-powered digital angle sensor that is compact, simple, and lightweight is introduced. This sensor eliminates the need for an external power supply and demonstrates highly sensitive signal detection at the volt level when the variable structure of the aircraft is working. The sensor is designed with a thickness of 7.3 mm, a volume of 16.6 cm³, and a weight of 9.85 g. Its lightweight and compact structure allows for seamless integration into aircraft without causing significant impact. The sensor not only provides real-time monitoring the aircraft's variable structure deflection states, including deflection direction and angle but also alerts operators to any anomalies in deflection. Its small size and self-powered capability make it an ideal solution for aircraft applications, enhancing safety and efficiency during flight.

Thermally Chargeable Supercapacitors

In article number 2301849, Shohei Horike, Qingshuo Wei, and co-workers develop a thermally chargeable supercapacitor module that generates a large thermoelectromotive force without requiring a DC-to-DC converter. Optimization of the circuit comprising the module and voltage detector enables intermittent powering of electric devices including LED, motor, piezo speaker, and beacon. This approach represents a significant step toward inexpensive energy harvesting technologies for web-connected sensing devices.

Self-Powered Sensing

In article number 2400255, Ji-Sik Kim, Sang-Shik Park, and co-workers fabricate a dual-modal self-powered sensor capable of emitting photons and electrical signals in response to mechanical stimuli using ZnS:Cu/polydimethylsiloxane (PDMS) composite and a biocompatible silk fibroin/PDMS composite. The hybrid sensor responds to multiple mechanical stimuli. The sensor can be applied to wearable technology, biomechanics, human–machine interaction, security, and energy harvesting.

Robotic Soft Grippers

In article number 2301004, Juntian Qu and co-authors discuss the state-of-the-art technologies and applications of robotic soft grippers, specifically in categories of materials and manufacturing, actuation, sensing and control technologies, along with a summary of existing challenges and perspectives of corresponding solutions.

Two-photon Polymerization (2PP) process for high-resolution 3D printing presents an opportunity to design micro-scale structures with a high surface-to-volume ratio for highly responsive devices. However, these acrylate or thiol-based resins are electrically insulating and non-functional in nature, therefore limiting their widespread application in biosensing and biotechnology. Here, a novel conductive polymeric composite resin to print conductive 3D micro-structures via the 2PP technique is developed and its application in sensing are demonstrated. The composite consists of acrylate-based 2PP resin and Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), a conductive and biocompatible organic semiconductor The PEDOT:PSS incorporation in resin through Raman and X-ray photoelectron spectroscopy (XPS) is studied. An electrical conductivity of 3.5 × 10² S cm⁻¹ in a 20 µm long and 10 µm high 3D printed micro-structure which is suitable for electronic applications is achieved. An ultra-fast micro-3D printed humidity sensor with a response and recovery time of 0.15 and 0.3 s respectively is demonstrated. The printed sensors show high sensitivity in humidity levels of 0–80%RH. As a proof of concept, the real-time respiration of a human body is recorded, implying a potential application in health monitoring systems.

2D hybrid perovskites have emerged as a promising alternative material to address the environmental stability and the ion-migration of the 3D perovskites for direct X-ray detector applications. Nevertheless, the X-ray detection performance of the 2D hybrid perovskites still lags because of its low X-ray attenuation ability and limited solubility for thick film deposition. Here, a high-performance X-ray detector in Dion-Jacobson 2D hybrid perovskite, 2(aminomethyl) pyridinium lead bromide (2AMPPbBr₄), is studied. 2AMPPbBr₄ exhibits an ultra-short interlayer distance of 3.43 Å, leading to high X-ray attenuation ability. Furthermore, DFT results indicate that 2AMPPbBr₄ exhibits type II band alignment between 2AMP²⁺ ligand and the [PbI₆]⁴⁻ layers, facilitating effective spatial separation of photo-generated carriers. The X-ray detector made of 2AMPPbBr₄ with an average thickness of 200 µm is realized via an improved drop-casting method. An improved X-ray sensitivity of 3933.88 µC Gy⁻¹ cm⁻² and a low detection limit of 4.17 nGy s⁻¹ is achieved. This work paves the way for high-performance X-ray detectors based on the emerging 2D perovskite materials.

Flexible hybrid electronics (FHE) is an emerging area that combines printed electronics and ultra-thin chip (UTC) technology to deliver high performance needed in applications such as wearables, robotics, and internet-of-things etc. The integration of UTCs on flexible substrates and the access to devices on them requires high resolution interconnects, which is a challenging task as thermal and mechanical mismatches do not allow conventional bonding methods to work. To address this challenge, the resource-efficient, area-efficient, and low-cost printing routes for obtaining vertical interconnection accesses (VIAs) are demonstrated here. It is demonstrated how high-resolution printers (electrohydrodynamic and extrusion-based direct-ink writing printers) can be used for patterning of high-resolution, freeform, vertical conductive structures. To access the transistors on UTCs, the VIAs, obtained using conventional photolithography and plasma etching steps, are filled with conductive silver nanoparticle-based ink/paste using high-resolution printers. Comprehensive studies are performed to compare and benchmark in terms of: i) the printing speed and throughput of the printers, ii) the electrical performance of vertically connected transistors in UTCs, and iii) the electrical performance stability of FHE system (interconnects and UTCs) under mechanical bending conditions. This in-depth study shows the potential use of printing technologies for development of high-density 3D integrated FHE systems.