Toughening Double‐Network Hydrogels by Polyelectrolytes

Advanced Materials, Год журнала: 2023, Номер 35(26)

Опубликована: Март 20, 2023

The Hoffmeister effect of inorganic salts is verified as a promising way to toughen hydrogels, however, the high concentration may be accompanied by poor biocompatibility. In this work, it found that polyelectrolytes can obviously elevate mechanical performances hydrogels through effect. introduction anionic poly(sodium acrylate) into poly(vinyl alcohol) (PVA) hydrogel induces aggregation and crystallization PVA boost properties resulting double-network hydrogel: elevation 73, 64, 28, 135, 19 times in tensile strength, compressive Young's modulus, toughness, fracture energy compared with poly(acrylic acid), respectively. It noteworthy flexibly tuned variation polyelectrolyte concentration, ionization degree, relative hydrophobicity ionic component, type wide range. This strategy work for other Hoffmeister-effect-sensitive polymers polyelectrolytes. Also, urea bonds further improve antiswelling capability hydrogels. As biomedical patch, advanced efficiently inhibit hernia formation promote regeneration soft tissues an abdominal wall defect model.

Язык: Английский

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Deep-Learning Enabled Active Biomimetic Multifunctional Hydrogel Electronic Skin

ACS Nano, Год журнала: 2023, Номер 17(16), С. 16160 - 16173

Опубликована: Июль 31, 2023

There is huge demand for recreating human skin with the functions of epidermis and dermis interactions physical world. Herein, a biomimetic, ultrasensitive, multifunctional hydrogel-based electronic (BHES) was proposed. Its function mimicked using poly(ethylene terephthalate) nanoscale wrinkles, enabling accurate identification materials through capabilities to gain/lose electrons during contact electrification. Internal mechanoreceptor by interdigital silver electrodes stick–slip sensing identify textures/roughness. The patterned microcone hydrogel, achieving pressure sensors high sensitivity (17.32 mV/Pa), large range (20–5000 Pa), low detection limit, fast response (10 ms)/recovery time (17 ms). Assisted deep learning, this BHES achieved accuracy minimized interference in identifying (95.00% 10 materials) textures (97.20% four roughness cases). By integrating signal acquisition/processing circuits, wearable drone control system demonstrated three-degree-of-freedom movement enormous potentials soft robots, self-powered human–machine interaction interfaces digital twins.

Язык: Английский

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Highly conductive tissue-like hydrogel interface through template-directed assembly

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Апрель 18, 2023

Abstract Over the past decade, conductive hydrogels have received great attention as tissue-interfacing electrodes due to their soft and tissue-like mechanical properties. However, a trade-off between robust properties good electrical has prevented fabrication of tough, highly hydrogel limited its use in bioelectronics. Here, we report synthetic method for realization mechanically tough with modulus. We employed template-directed assembly method, enabling arrangement disorder-free, highly-conductive nanofibrous network inside stretchable, hydrated network. The resultant exhibits ideal material. Furthermore, it can provide adhesion (800 J/m 2 ) diverse dynamic wet tissue after chemical activation. This enables suture-free adhesive-free, high-performance successfully demonstrated ultra-low voltage neuromodulation high-quality epicardial electrocardiogram (ECG) signal recording based on vivo animal models. provides platform interfaces various bioelectronic applications.

Язык: Английский

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Engineering Tough Metallosupramolecular Hydrogel Films with Kirigami Structures for Compliant Soft Electronics

Small, Год журнала: 2021, Номер 17(41)

Опубликована: Сен. 12, 2021

Abstract A simple and effective approach is demonstrated to fabricate tough metallosupramolecular hydrogel films of poly(acrylic acid) by one‐pot photopolymerization the precursor solution in presence Zr 4+ ions that form coordination complexes with carboxyl groups serve as physical crosslinks matrix. Both as‐prepared equilibrated are transparent, tough, stable over a wide range temperature, ionic strength, pH. The thickness can be easily tailored minimum value ≈7 μm. Owing fast polymerization gelation process, kirigami structures facilely encoded gel photolithographic polymerization, affording versatile functions such additional stretchability better compliance planar encapsulate objects sophisticated geometries important for design soft electronics. By stencil printing liquid metal on film structure, integrated electronics shows good cover curved surfaces high sensitivity monitor human motions. Furthermore, this strategy applied diverse natural synthetic macromolecules containing develop films, which will open opportunities applications biomedical engineering fields.

Язык: Английский

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Functionalized Hydrogel-Based Wearable Gas and Humidity Sensors

Nano-Micro Letters, Год журнала: 2023, Номер 15(1)

Опубликована: Май 24, 2023

Abstract Breathing is an inherent human activity; however, the composition of air we inhale and gas exhale remains unknown to us. To address this, wearable vapor sensors can help people monitor in real time avoid underlying risks, for early detection treatment diseases home healthcare. Hydrogels with three-dimensional polymer networks large amounts water molecules are naturally flexible stretchable. Functionalized hydrogels intrinsically conductive, self-healing, self-adhesive, biocompatible, room-temperature sensitive. Compared traditional rigid sensors, hydrogel-based humidity directly fit skin or clothing, more suitable real-time monitoring personal health safety. In this review, current studies on investigated. The required properties optimization methods introduced. Subsequently, existing reports response mechanisms summarized. Related works their application safety presented. Moreover, potential field sensing elucidated. Finally, research status, challenges, future trends hydrogel gas/humidity discussed.

Язык: Английский

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Adhesive and Hydrophobic Bilayer Hydrogel Enabled On‐Skin Biosensors for High‐Fidelity Classification of Human Emotion

Advanced Functional Materials, Год журнала: 2022, Номер 32(29)

Опубликована: Апрель 22, 2022

Abstract Traditional human emotion recognition is based on electroencephalogram (EEG) data collection technologies which rely plenty of rigid electrodes and lack anti‐interference, wearing comfort, portability. Moreover, a significant distribution difference in EEG also results low classification accuracy. Here, on‐skin biosensors with adhesive hydrophobic bilayer hydrogel (AHBH) as interfaces for high accuracy are proposed. The AHBH achieves remarkable adhesion (59.7 N m −1 ) by combining the mechanism catechol groups electrostatic attraction. Meanwhile, synergistic effects group rearrangements surface energy reduction, AHB‐hydrophobic layer exhibits 133.87° water contact angles through treatment only 0.5 h. Hydrogen bonds introduced to form seamless adhesive‐hydrophobic interface inhibit attenuation, respectively. With an ideal device/skin interface, biosensor can reliably collect high‐quality electrophysiological signals even under vibration, sweating, long‐lasting monitoring condition. Furthermore, electrodes, processing, wireless modules integrated into portable headband EEG‐based classification. A domain adaptive neural network transfer learning technique alleviate effect shift achieve

Язык: Английский

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Hydrogel Nanoarchitectonics of a Flexible and Self‐Adhesive Electrode for Long‐Term Wireless Electroencephalogram Recording and High‐Accuracy Sustained Attention Evaluation

Advanced Materials, Год журнала: 2023, Номер 35(12)

Опубликована: Янв. 9, 2023

Hydrogels are ideal building blocks to fabricate the next generation of electrodes for acquiring high-quality physiological electrical signals, example, electroencephalography (EEG). However, collection EEG signals still suffers from electrode deformation, sweating, extensive body motion and vibration, environmental interference. Herein, polyvinyl alcohol polyvinylpyrrolidone selected prepare a hydrogel network with tissue-like modulus excellent flexibility. Additionally, polydopamine nanoparticles, obtained by peroxidation, integrated into endow them higher transparency, self-adhesion, lower impedance. Consequently, multichannel wirelessly operated can establish conformal stable interface tissue illustrate high channel uniformity, low interfacial contact impedance, power noise, long-term stability, tolerance sweat motion. Furthermore, shows unprecedented ability classify recorded prefrontal seven-category sustained attention accuracy (91.5%), having great potential applications in assessment human consciousness multifunctional diagnoses.

Язык: Английский

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Bioresorbable, wireless, and battery-free system for electrotherapy and impedance sensing at wound sites

Science Advances, Год журнала: 2023, Номер 9(8)

Опубликована: Фев. 22, 2023

Chronic wounds, particularly those associated with diabetes mellitus, represent a growing threat to public health, additional notable economic impacts. Inflammation these wounds leads abnormalities in endogenous electrical signals that impede the migration of keratinocytes needed support healing process. This observation motivates treatment chronic stimulation therapy, but practical engineering challenges, difficulties removing hardware from wound site, and absence means monitor process create barriers widespread clinical use. Here, we demonstrate miniaturized wireless, battery-free bioresorbable electrotherapy system overcomes challenges. Studies based on splinted diabetic mouse model confirm efficacy for accelerated closure by guiding epithelial migration, modulating inflammation, promoting vasculogenesis. Changes impedance provide tracking The results simple effective platform site electrotherapy.

Язык: Английский

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Deep Eutectic Solvents‐Based Ionogels with Ultrafast Gelation and High Adhesion in Harsh Environments

Advanced Functional Materials, Год журнала: 2023, Номер 33(9)

Опубликована: Фев. 1, 2023

Adhesive materials have recently drawn intensive attention due to their excellent sealing ability, thereby stimulating advances in science and industrial usage. However, reported adhesives usually exhibit weak adhesion strength, require high pressure for strong bonding, display severe deterioration various harsh environments. In this work, instead of water or organic solvents, a deep eutectic solution (DES) was used as the medium photopolymerization zwitterionic polarized monomers, thus generating novel ionogel with tunable mechanical properties. Multiple hydrogen bonds electrostatic interactions between DES monomers facilitated ultrafast gelation instant bonding without any external pressure, which rarely previously. Furthermore, different environments (e.g., water, acidic basic buffers, saline solutions) onto hydrophilic glass tissues) hydrophobic polymethyl methacrylate, polystyrene, polypropylene) adherends demonstrated. Also, stretchability at extreme temperatures (-80 80 °C) indicated its widespread applications. biocompatible showed burst stomach intestine tissues prevent liquid leakage, highlighting potential an adhesive patch. This provides unprecedented opportunities fields packaging industry, marine engineering, medical adhesives, electronic assembly.

Язык: Английский

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3D printed triboelectric nanogenerator as self-powered human-machine interactive sensor for breathing-based language expression

Nano Research, Год журнала: 2022, Номер 15(8), С. 7460 - 7467

Опубликована: Май 5, 2022

Язык: Английский

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