A Highly-Sensitive Omnidirectional Acoustic Sensor for Enhanced Human-Machine Interaction.

Acoustic sensor-based human-machine interaction (HMI) plays a crucial role in natural and efficient communication in intelligent robots. However, accurately identifying and tracking omnidirectional sound sources, especially in noisy environments still remains a notable challenge. Here, a self-powered triboelectric stereo acoustic sensor (SAS) with omnidirectional sound recognition and tracking capabilities by a 3D structure configuration is presented.

Spontaneous suprachoroidal hemorrhage treated by gas tamponade in a refractory glaucoma patient with rhegmatogenous retinal detachment: a case report.

We are reporting the successful treatment of a rare case of spontaneous suprachoroidal hemorrhage (SSCH) in a young refractory glaucoma patient with rhegmatogenous retinal detachment (RRD). The 34-year-old male was admitted to our hospital having experienced pain in his right eye for two days. The patient had a history of glaucoma and long axial length in the right eye with chronic poorly controlled intraocular pressure (IOP) and acute hypotony.

Spontaneously established reverse electric field to enhance the performance of triboelectric nanogenerators via improving Coulombic efficiency.

Mechanical energy harvesting using triboelectric nanogenerators is a highly desirable and sustainable method for the reliable power supply of widely distributed electronics in the new era; however, its practical viability is seriously challenged by the limited performance because of the inevitable side-discharge and low Coulombic-efficiency issues arising from electrostatic breakdown. Here, we report an important progress on these fundamental problems that the spontaneously established reverse electric field between the electrode and triboelectric layer can restrict the side-discharge problem in triboelectric nanogenerators. The demonstration employed by direct-current triboelectric nanogenerators leads to a high Coulombic efficiency (increased from 28.

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.

Recent Progress of Advanced Materials for Triboelectric Nanogenerators.

Triboelectric nanogenerators (TENGs) have received intense attention due to their broad application prospects in the new era of internet of things (IoTs) as distributed power sources and self-powered sensors. Advanced materials are vital components for TENGs, which decide their comprehensive performance and application scenarios, opening up the opportunity to develop efficient TENGs and expand their potential applications. In this review, a systematic and comprehensive overview of the advanced materials for TENGs is presented, including materials classifications, fabrication methods, and the properties required for applications.

Discharge domains regulation and dynamic processes of direct-current triboelectric nanogenerator.

Direct-current triboelectric nanogenerators arising from electrostatic breakdown can eliminate the bottleneck problem of air breakdown in conventional triboelectric nanogenerators, offering critical benefits of constant-current output, resistance to electromagnetic interference, and high output power density. Previous understanding is that its output characteristics are described by a capacitor-breakdown model or dictated by one or two discharge domains in direct-current triboelectric nanogenerators. Here, we demonstrate that the former holds only for ideal conditions and the latter cannot fully explain the dynamic process and output performance.

Standardized measurement of dielectric materials' intrinsic triboelectric charge density through the suppression of air breakdown.

Triboelectric charge density and energy density are two crucial factors to assess the output capability of dielectric materials in a triboelectric nanogenerator (TENG). However, they are commonly limited by the breakdown effect, structural parameters, and environmental factors, failing to reflect the intrinsic triboelectric behavior of these materials. Moreover, a standardized strategy for quantifying their maximum values is needed.

Achieving Ultrahigh Effective Surface Charge Density of Direct-Current Triboelectric Nanogenerator in High Humidity.

As an emerging energy-harvesting technology, the triboelectric nanogenerator (TENG) is considered a powerful driving force toward the new-era of Internet of Things and artificial intelligence, but its output performance is dramatically influenced by environmental humidity. Herein, a direct current TENG (DC-TENG) based on the triboelectrification effect and electrostatic breakdown is reported to address the problem of output attenuation in high humidity environments for the conventional TENGs. It is found that high humidity not only enhances the sliding triboelectrification effect of hydrophobic triboelectric materials, but also promotes the electrostatic breakdown process for DC-TENG, thus contributing to the improvement of DC-TENG output.

A Tuning-Fork Triboelectric Nanogenerator with Frequency Multiplication for Efficient Mechanical Energy Harvesting.

As a new technology for high-entropy energy harvesting, a triboelectric nanogenerator (TENG) has broad applications in sensor networks and internet of things as a power source, but its average power density is limited by the fixed low-frequency output. Here, a frequency-multiplication TENG based on intrinsic high frequency of tuning fork is proposed which enables converting low-frequency mechanical energy into high-frequency electric energy. A tuning-fork TENG is used to systematically study the effects of intrinsic frequency, dielectric's thickness, and gap distance on its electric performance, and a total transferred charges of 4.

A Self-Powered Dual-Type Signal Vector Sensor for Smart Robotics and Automatic Vehicles.

Automatic control systems are the most efficient technology for reducing labor cost while improving work efficiency. Vector motion monitoring is indispensable for the normal operation of automatic control systems. Here, a self-powered dual-type signal triboelectric nanogenerator (DS-TENG) is designed through integrating an alternating-current TENG and a direct-current TENG, which can monitor vector movement in real time based on pulse signal counts.

Establishment of the New Zealand white rabbit animal model of fatty keratopathy associated with corneal neovascularization.

The term fatty keratopathy is used to describe the phenomenon of fat deposition caused by corneal neovascularization, which will severely affect the eye's beauty and vision. The purpose of this study was to establish a New Zealand white rabbit animal model of fatty keratopathy, that is, the establishment of an animal model of fatty keratopathy. The goal was achieved by the combination of a corneal neovascularization animal model and a hyperlipidemia animal model.

Improving Degradation Efficiency of Organic Pollutants through a Self-Powered Alternating Current Electrocoagulation System.

Although electrocoagulation technology has been widely researched in wastewater treatment, high energy consumption and electrode passivation are still the main challenges for its widespread applications. Here, we propose a self-powered electrocoagulation system based on a triboelectric nanogenerator (TENG) with alternating current (AC) outputs to solve these two issues, and thus enhance the removal efficiency of organic pollutants. Compared with the direct current source, the AC power source can reduce the electrode passivation, produce more aluminum hydroxide compounds after consuming an equal amount of charges, and thus improve the degradation efficiency.

Selection rules of triboelectric materials for direct-current triboelectric nanogenerator.

The rapid development of Internet of Things and artificial intelligence brings increasing attention on the harvesting of distributed energy by using triboelectric nanogenerator (TENG), especially the direct current TENG (DC-TENG). It is essential to select appropriate triboelectric materials for obtaining a high performance TENG. In this work, we provide a set of rules for selecting the triboelectric materials for DC-TENG based on several basic parameters, including surface charge density, friction coefficient, polarization, utilization rate of charges, and stability.

Low-Cost, Environmentally Friendly, and High-Performance Triboelectric Nanogenerator Based on a Common Waste Material.

With the great progress in human activities and production technologies, the waste inevitably produced causes not only environmental pollution but also resource waste; meanwhile, the mobile and portable electronic devices urgently need a distributed and sustainable energy source to ensure their stable operation. Here, the waste pollutants (milk cartons) generated from daily life, commonly associated with environmental concerns, are instead identified as an available resource for preparing an emerging energy harvester (triboelectric nanogenerator, TENG), which can convert ubiquitous mechanical energy into electric power. Consequently, based on the waste material, the initial charge density of the TENG is as low as 0.

A Fully Self-Powered Vibration Monitoring System Driven by Dual-Mode Triboelectric Nanogenerators.

Vibration sensor is very necessary for monitoring the structural health of constructions. However, it is still a major challenge to meet simultaneously real-time monitoring, continuous assessment, and early incident warning in a simple device without a complicated power and analysis system. Here, we report a self-powered vibration sensor system to achieve real-time and continuous detection of the vibration characteristics from a dual-mode triboelectric nanogenerator (AC/DC-TENG), which can produce either alternating current (AC) or direct current (DC) within different operation zones.