Ionic Rectification by Dynamic Regulation of the Electric Double Layer at the Hydrogel Interface.

Hydrogels play a pivotal role in the realm of iontronics, contributing to the realization of futuristic human-machine interactions. The electric double layer (EDL) between the hydrogel and electrode provides an essential ionic-electronic coupling interface. While prior investigations primarily delved into elucidating the formation mechanism of the EDL, our study shifts the focus to showcasing the current generation through the mechanical modulation of the EDL at the hydrogel-metal interfaces.

Quantifying the interfacial triboelectricity in inorganic-organic composite mechanoluminescent materials.

Mechanoluminescence (ML) sensing technologies open up new opportunities for intelligent sensors, self-powered displays and wearable devices. However, the emission efficiency of ML materials reported so far still fails to meet the growing application requirements due to the insufficiently understood mechano-to-photon conversion mechanism. Herein, we propose to quantify the ability of different phases to gain or lose electrons under friction (defined as triboelectric series), and reveal that the inorganic-organic interfacial triboelectricity is a key factor in determining the ML in inorganic-organic composites.

Spontaneous Wetting Induced by Contact-Electrification at Liquid-Solid Interface.

Wettability significantly influences various surface interactions and applications at the liquid-solid interface. However, the understanding is complicated by the intricate charge exchange occurring through contact electrification (CE) during this process. The understanding of the influence of triboelectric charge on wettability remains challenging, especially due to the complexities involved in concurrently measuring contact angles and interfacial electrical signals.

Adjustment methods of Schottky barrier height in one- and two-dimensional semiconductor devices.

The Schottky contact which is a crucial interface between semiconductors and metals is becoming increasingly significant in nano-semiconductor devices. A Schottky barrier, also known as the energy barrier, controls the depletion width and carrier transport across the metal-semiconductor interface. Controlling or adjusting Schottky barrier height (SBH) has always been a vital issue in the successful operation of any semiconductor device.

Multistrand Twisted Triboelectric Kevlar Yarns for Harvesting High Impact Energy, Body Injury Location and Levels Evaluation.

Developing ultrahigh-strength fabric-based triboelectric nanogenerators for harvesting high-impact energy and sensing biomechanical signals is still a great challenge. Here, the constraints are addressed by design of a multistrand twisted triboelectric Kevlar (MTTK) yarn using conductive and non-conductive Kevlar fibers. Manufactured using a multistrand twisting process, the MTTK yarn offers superior tensile strength (372 MPa), compared to current triboelectric yarns.

Transformer Monitoring with Electromagnetic Energy Transmission and Wireless Sensing.

To ensure stable and normal transformer operation, light gas protection of the transformer Buchholz relay is essential. However, false alarms related to light gas protection are common, and troubleshooting them often requires on-site gas sampling by personnel. During this time, the transformer's operating state may rapidly deteriorate, posing a safety threat to field staff.

A Dual-Mode Triboelectric Nanogenerator for Efficiently Harvesting Droplet Energy.

Triboelectric nanogenerator (TENG) is a promising solution to harvest the low-frequency, low-actuation-force, and high-entropy droplet energy. Conventional attempts mainly focus on maximizing electrostatic energy harvest on the liquid-solid surface, but enormous kinetic energy of droplet hitting the substrate is directly dissipated, limiting the output performance. Here, a dual-mode TENG (DM-TENG) is proposed to efficiently harvest both electrostatic energy at liquid-solid surface from a droplet TENG (D-TENG) and elastic potential energy of the vibrated cantilever from a contact-separation TENG (CS-TENG).

A High-Voltage-Specialized Direct-Current Triboelectric Nanogenerator for Air Purification.

Human health and the environment face significant challenges of air pollution, which is predominantly caused by PM2.5 or PM10 particles. Existing control methods often require elevated energy consumption or bulky high-voltage electrical equipment.

Closed-Loop Wearable Device Network of Intrinsically-Controlled, Bilateral Coordinated Functional Electrical Stimulation for Stroke.

Innovative functional electrical stimulation has demonstrated effectiveness in enhancing daily walking and rehabilitating stroke patients with foot drop. However, its lack of precision in stimulating timing, individual adaptivity, and bilateral symmetry, resulted in diminished clinical efficacy. Therefore, a closed-loop wearable device network of intrinsically controlled functional electrical stimulation (CI-FES) system is proposed, which utilizes the personal surface myoelectricity, derived from the intrinsic neuro signal, as the switch to activate/deactivate the stimulation on the affected side.

Progress in the Treatment of Central Nervous System Diseases Based on Nanosized Traditional Chinese Medicine.

Traditional Chinese Medicine (TCM) is widely used in clinical practice to treat diseases related to central nervous system (CNS) damage. However, the blood-brain barrier (BBB) constitutes a significant impediment to the effective delivery of TCM, thus substantially diminishing its efficacy. Advances in nanotechnology and its applications in TCM (also known as nano-TCM) can deliver active ingredients or components of TCM across the BBB to the targeted brain region.

Sustainable paper electronics and neuromorphic paper chip.

Paper electronics have received a lot of attention due to their special properties of mechanical flexibility/foldability, sustainability, biodegradability, light weight, and low cost. It provides a superb on-chip prototype with simple modular design and feasible energy-autonomous features, which can surpass the problems of inconvenience and possible pollution caused by conventional power sources by integrating different functional modules. Commonly, the sustainable operation of integrated paper electronics can be guaranteed by the basic components, including energy-harvesting devices, energy-storage devices, and low-power-consuming functional circuits/devices.

Piezoelectric hydrogel for treatment of periodontitis through bioenergetic activation.

The impaired differentiation ability of resident cells and disordered immune microenvironment in periodontitis pose a huge challenge for bone regeneration. Herein, we construct a piezoelectric hydrogel to rescue the impaired osteogenic capability and rebuild the regenerative immune microenvironment through bioenergetic activation. Under local mechanical stress, the piezoelectric hydrogel generated piezopotential that initiates osteogenic differentiation of inflammatory periodontal ligament stem cells (PDLSCs) via modulating energy metabolism and promoting adenosine triphosphate (ATP) synthesis.

Recent Progress in Implantable Drug Delivery Systems.

In recent years, tremendous effort is devoted to developing platforms, such as implantable drug delivery systems (IDDSs), with temporally and spatially controlled drug release capabilities and improved adherence. IDDSs have multiple advantages: i) the timing and location of drug delivery can be controlled by patients using specific stimuli (light, sound, electricity, magnetism, etc.).

A high-current hydrogel generator with engineered mechanoionic asymmetry.

Mechanoelectrical energy conversion is a potential solution for the power supply of miniaturized wearable and implantable systems; yet it remains challenging due to limited current output when exploiting low-frequency motions with soft devices. We report a design of a hydrogel generator with mechanoionic current generation amplified by orders of magnitudes with engineered structural and chemical asymmetry. Under compressive loading, relief structures in the hydrogel intensify net ion fluxes induced by deformation gradient, which synergize with asymmetric ion adsorption characteristics of the electrodes and distinct diffusivity of cations and anions in the hydrogel matrix.

Mechanism of V-Shaped Pits on Promoting Hole Injection in the InGaN MQWs: First-Principles Investigation.

In the InGaN multiple quantum wells (MQWs), V-shaped pits play a crucial role in carrier transport, which directly affects emitting efficiency. First-principles calculations are applied to investigate the formation of the V-shaped pits, and the results indicate that they are inclined to form in the N-rich environment. Meanwhile, we calculate the interfacial electronic properties of the sidewalls of the V-shaped pits with varying indium (In) and magnesium (Mg) compositions.

Polynary energy harvesting and multi-parameter sensing in the heatwave environment of industrial factory buildings by an integrated triboelectric-thermoelectric hybrid generator.

Taking advantage of a hybrid generator to simultaneously collect polynary energy from a single energy source provides a feasible solution for the energy dilemma in the new era. Herein, we integrate a triboelectric nanogenerator and a thermoelectric generator for polynary energy harvesting and self-powered sensing of heatwaves in large-scale industrial factory buildings, which contains both thermal energy and wind energy. The new design of the fan-shaped rotation triboelectric nanogenerator (FR-TENG) makes it more compact and easily integrated.

Advancements and Prospects of Flexoelectricity.

The flexoelectric effect, as a novel form of the electromechanical coupling phenomenon, has attracted significant attention in the fields of materials science and electronic devices. It refers to the interaction between strain gradients and electric dipole moments or electric field intensity gradients and strain. In contrast to the traditional piezoelectric effect, the flexoelectric effect is not limited by material symmetry or the Curie temperature and exhibits a stronger effect at the nanoscale.

Tribovoltaic Effect: Origin, Interface, Characteristic, Mechanism & Application.

Tribovoltaic effect is a phenomenon of the generation of direct voltage and current by the mechanical friction on semiconductor interface, which exhibits a brand-new energy conversion mechanism by the coupling of semiconductor and triboelectrification. Here, the origin, interfaces, characteristics, mechanism, coupling effect and application of the tribovoltaic effect is summarized and reviewed. The tribovoltaic effect is first proposed in 2019, which has developed in various forms tribovoltaic nanogenerator (TVNG) including metal-semiconductor, metal-insulator-semiconductor, semiconductor-semiconductor, liquid-solid and flexible interfaces.

Ultrasensitive Touch Sensor for Simultaneous Tactile and Slip Sensing.

Touch is a general term to describe mechanical stimuli. It is extremely difficult to develop touch sensors that can detect different modes of contact forces due to their low sensitivity and data decoupling. Simultaneously conducting tactile and slip sensing presents significant challenges for the design, structure, and performance of sensors.

Strategies to Improve the Output Performance of Triboelectric Nanogenerators.

Triboelectric nanogenerators (TENGs) can collect and convert random mechanical energy into electric energy, with remarkable advantages including broadly available materials, straightforward preparation, and multiple applications. Over the years, researchers have made substantial advancements in the theoretical and practical aspects of TENG. Nevertheless, the pivotal challenge in realizing full applications of TENG lies in ensuring that the generated output meets the specific application requirements.

Triboelectric Spectroscopy for In Situ Chemical Analysis of Liquids.

Chemical analysis of ions and small organic molecules in liquid samples is crucial for applications in chemistry, biology, environmental sciences, and health monitoring. Mainstream electrochemical and chromatographic techniques often suffer from complex and lengthy sample preparation and testing procedures and require either bulky or expensive instrumentation. Here, we combine triboelectrification and charge transfer on the surface of electrical insulators to demonstrate the concept of triboelectric spectroscopy (TES) for chemical analysis.

Chirality of Copper-Amino Acid Nanoparticles Determines Chemodynamic Cancer Therapeutic Outcome.

Chirality is a prevalent characteristic in nature, where biological systems exhibit a significant preference for specific enantiomers of biomolecules. However, there is a limited exploration into utilizing nanomaterials' chirality to modulate their interactions with intracellular substances. In this study, self-assembled copper-cysteine chiral nanoparticles and explore the influence of their charity on cancer chemodynamic therapy (CDT) are fabricated.

Hierarchical porous dual-mode thermal management fabrics achieved by regulating solar and body radiations.

Personal thermal management (PTM) of fabrics is vital for human health; the ever-changing location of the human body poses a big challenge for fabrics to maintain a favorable metabolic temperature. Herein, a dual-mode thermal management fabric is designed to achieve both cooling and heating functions by regulating simultaneously solar and body radiations. The cooling or heating mode can be exchanged by flipping the fabric without an external energy supply.