From Fluorescence-Transfer-Lightening-Printing-Assisted Conductive Adhesive Nanocomposite Hydrogels toward Wearable Interactive Optical Information-Electronic Strain Sensors.

The interactive flexible device, which monitors the human motion in optical and electrical synergistic modes, has attracted growing attention recently. The incorporation of information attribute within the optical signal is deemed advantageous for improving the interactive efficiency. Therefore, the development of wearable optical information-electronic strain sensors holds substantial promise, but integrating and synergizing various functions and realizing strain-mediated information transformation keep challenging. Herein, an amylopectin (AP) modified nanoclay/polyacrylamide-based nanocomposite (NC) hydrogel and an aggregation-induced-emission-active ink are fabricated. Through the fluorescence-transfer printing of the ink onto the hydrogel film in different strains with nested multiple symbolic information, a wearable interactive fluorescent information-electronic strain sensor is developed. In the sensor, the nanoclay plays a synergistic "one-stone-three-birds" role, contributing to "lightening" fluorescence (≈80 times emission intensity enhancement), ionic conductivity, and excellent stretchability (>1000%). The sensor has high biocompatibility, resilience (elastic recovery ratio: 97.8%), and strain sensitivity (gauge factor (GF): 10.9). Additionally, the AP endows the sensor with skin adhesiveness. The sensor can achieve electrical monitoring of human joint movements while displaying interactive fluorescent information transformation. This research poses an efficient strategy to develop multifunctional materials and provides a general platform for achieving next-generation interactive devices with prospective applications in wearable devices, human-machine interfaces, and artificial intelligence.

Information-Storage Expansion Enabled by a Resilient Aggregation-Induced-Emission-Active Nanocomposite Hydrogel.

Advanced materials with high performance and distinctive function are one of the main driving forces for the development of human society. The selection of appropriate materials and adequately utilizing their features to apply them in a specific area rationally are of great significance but remain challenging. Herein, an aggregation-induced emission (AIE)-active nanocomposite (NC) hydrogel is developed by introducing a pH-responsive AIE luminogen (AIEgen) into a Laponite XLS/polyacrylamide-based NC hydrogel (Laponite is a trademark of the company BYK Additives Ltd.). The AIEgen can protonate to interact with the negatively charged clay through the electrostatic interaction, which results in a drastic fluorescence enhancement due to the restriction of intramolecular motion by the rigid clay to the protonated AIEgen. This behavior facilitates the input of fluorescent information with a high contrast ratio in the hydrogel by acid stimulation. Moreover, by utilizing the excellent resilience of the hydrogel, hierarchically inputting and displaying the information in the original and stretched states of the hydrogel film is realized, which achieves information-storage expansion and dual-encryption via switching between stretching and restoring the film. This work showcases fully and synergistically utilizing the superiorities of various advanced materials to achieve superior applications and should guide the future development of advanced materials in emerging areas.

Nanomaterials-Functionalized Hydrogels for the Treatment of Cutaneous Wounds.

Hydrogels have been utilized extensively in the field of cutaneous wound treatment. The introduction of nanomaterials (NMs), which are a big category of materials with diverse functionalities, can endow the hydrogels with additional and multiple functions to meet the demand for a comprehensive performance in wound dressings. Therefore, NMs-functionalized hydrogels (NMFHs) as wound dressings have drawn intensive attention recently. Herein, an overview of reports about NMFHs for the treatment of cutaneous wounds in the past five years is provided. Firstly, fabrication strategies, which are mainly divided into physical embedding and chemical synthesis of the NMFHs, are summarized and illustrated. Then, functions of the NMFHs brought by the NMs are reviewed, including hemostasis, antimicrobial activity, conductivity, regulation of reactive oxygen species (ROS) level, and stimulus responsiveness (pH responsiveness, photo-responsiveness, and magnetic responsiveness). Finally, current challenges and future perspectives in this field are discussed with the hope of inspiring additional ideas.

Gel-Based Luminescent Conductive Materials and Their Applications in Biosensors and Bioelectronics.

The gel is an ideal platform for fabricating materials for bio-related applications due to its good biocompatibility, adjustable mechanical strength, and flexible and diversified functionalization. In recent decades, gel-based luminescent conductive materials that possess additional luminescence and conductivity simultaneously advanced applications in biosensors and bioelectronics. Herein, a comprehensive overview of gel-based luminescent conductive materials is summarized in this review. Gel-based luminescent conductive materials are firstly outlined, highlighting their fabrication methods, network structures, and functions. Then, their applications in biosensors and bioelectronics fields are illustrated. Finally, challenges and future perspectives of this emerging field are discussed with the hope of inspire additional ideas.