The sliding mode triboelectric nanogenerator (S-TENG) is an effective technology for in-plane low-frequency mechanical energy harvesting. However, as surface modification of tribo-materials and ...charge excitation strategies are not well applicable for this mode, output performance promotion of S-TENG has no breakthrough recently. Herein, we propose a new strategy by designing shielding layer and alternative blank-tribo-area enabled charge space-accumulation (CSA) for enormously improving the charge density of S-TENG. It is found that the shielding layer prevents the air breakdown on the interface of tribo-layers effectively and the blank-tribo-area with charge dissipation on its surface of tribo-material promotes charge accumulation. The charge space-accumulation mechanism is analyzed theoretically and verified by experiments. The charge density of CSA-S-TENG achieves a 2.3 fold enhancement (1.63 mC m
) of normal S-TENG in ambient conditions. This work provides a deep understanding of the working mechanism of S-TENG and an effective strategy for promoting its output performance.
The surface charge density of the tribolayer is the most parameter for developing a high performance triboelectric nanogenerator (TENG). Most previous works focused on the surface structural/chemical ...modification. Nevertheless, the internal space of the tribolayer and its mechanism exploration were less investigated. Herein, in this work, internal-space-charge zones are built through imbedding ravines and gullies in criss-crossed gold layers in the near-surface of the tribolayer, which leads to the high output performance of TENG. As experimental results manifest, the transfer charge density of gold-PDMS TENG (G-TENG) reaches 168 μC m–2. Through theoretical analyses, it is determined that gold layers act as the passageways and traps of the triboelectric charges when the charges drift to the internal space of the tribomaterial. Moreover, the transport and storage process of triboelectric charges in the frictional layer are investigated comprehensively by quantum mechanics for the first time. The calculation method of the output current of TENG is proposed, and the theoretical calculation results coincide with the test results well. The results verify the application of the theoretical model and help with the construction and development of the theoretical system of TENG. Meanwhile, the relative results can be directly attained by this new theoretical model, and it is possible to make full use of the theoretical analysis to achieve a better performance for TENG. This study paves an easy and novel way for enhancing the charge density of the tribolayer by internal space construction and a new underlying theoretical model.
People living with HIV(PLWH) are deemed more vulnerable to the SARS-CoV-2 infection than the uninfected population. Vaccination is an effective measure for COVID-19 control, yet, little knowledge ...exists about the willingness of men who have sex with men (MSM) living with HIV in China to be vaccinated.
This cross-sectional study evaluated the willingness of MSM living with HIV to receive COVID-19 vaccination in six cities of Guangdong, China, from July to September 2020. Factors associated with willingness to receive COVID-19 vaccination using multivariable logistic regression.
In total, we recruited 944 HIV-positive MSM with a mean age of 29.2 ± 7.7 years. Of all participants, 92.4% of them were willing to receive the COVID-19 vaccine. Participants who were separated, divorced, or widowed (adjusted OR: 5.29, 95%CI: 1.02-27.48), had an annual income higher than 9,000 USD (adjusted OR: 1.70, 95%CI: 1.01-2.86), had ever taken an HIV self-test (adjusted OR: 1.78, 95%CI: 1.07-2.95), had ever disclosed sexual orientation to a doctor/nurse (adjusted OR: 3.16, 95%CI: 1.33-7.50), had ever disclosed sexual orientation to others besides their male partners (adjusted OR: 2.18, 95%CI: 1.29-3.69) were more willing to receive the vaccine. Sex with a female partner in the past six months decreased the likelihood of willingness to receive the vaccine (adjusted OR: 0.40, 95%CI: 0.17-0.95). Economic burden, worry that my health condition could not bear the risk of receiving COVID-19 vaccines, and concern that the vaccination would affect the immune status and antiretroviral therapy were the main reasons for unwillingness to receive vaccination.
Our study showed that HIV-positive MSM had a high willingness to receive the COVID-19 vaccination. Targeted interventions such as health education should be conducted among MSM with HIV infection to enhance COVID-19 vaccine uptake.
Mechanical vibrations are ubiquitous and enriched energy sources found in everyday environments. However, harvesting these energies, such as from water flowing in the ocean and wind energy, remains a ...significant challenge due to their irregular, discontinuous, low‐vibration frequencies. The triboelectric nanogenerator (TENG) exhibits an effective approach to convert these low frequency mechanical energies into electrical energy. In this work, a new triboelectric and electromagnetic hybrid nanogenerator is fabricated by designing a crankshaft system that consists of a delicate crankshaft and a piston based off the physical vibration characteristics of tidal energy, wind energy, and other rotational energies. This newly designed hybrid nanogenerator demonstrates a high efficiency to harvest rotary energy and a wide range of other rotational energies using the vertical contact–separation mode nanogenerator with much lower friction. The device delivers an output power of 0.08 mW cm−2, and an electromagnetic generator is added to widen the capacity of the device to also collect energies with higher vibration frequencies. Moreover, this hybrid device can be employed in many fields, such as harvesting rotational energy from the wind and ocean. This device can replace the conventional linear motor to avoid or reduce electromagnetic interferences during precise microdevice testing processing.
Based on the crankshaft system consisting of a delicate crankshaft and piston, a newly designed hybrid nanogenerator shows high efficiency to harvest the rotary energy and other wide range of rotational energy in accordance with the vertical contact–separation mode nanogenerator with much less friction. The device delivers an output power of 0.08 mW cm−2.
Fire warning and monitoring are very important for public safety and environmental protection. However, most of the proposed wind energy conversion devices based on triboelectric nanogenerator (TENG) ...only work for unidirectional and high‐speed wind and face the challenge of fatigue damage and even failure caused by cyclic stress. Moreover, TENG guided by the theory of fluid dynamics needs further exploration. Herein, a flow‐induced vibration effect based TENG (F‐TENG) for continuously capturing and monitoring multidirectional breeze (1.8–4.3 m s−1) is developed to build a self‐powered intelligent fire detection system (SIFDS). A dynamic model is proposed to study the intrinsic interaction between the electrical properties of F‐TENG and wind. Since the model optimized F‐TENG is more adaptable to wind characteristics, it delivers better performance and higher durability compared with previous studies. Relying on the dynamic model and combining the relationship between F‐TENG's electrical output and wind characteristics, a self‐powered visual wind sensing system is obtained. F‐TENG successfully drives some electronic devices to monitor environmental information, which is expected to provide data for SIFDS to reduce fire hazards. This study can provide an in‐depth understanding of the electromechanical conversion mechanism and large‐scale capture and utilization of breeze energy.
A super‐durable triboelectric nanogenerator based on flow‐induced vibration (F‐TENG) is proposed. The wind‐impact object model is constructed to study the fluid–solid interaction mechanism and calculate the structure‐effect relationship. F‐TENG efficiently converts multidirectional breeze energy into stable electric energy and acts as a wind sensing system. The collected environmental information can be used to construct a self‐powered fire detection system.
Vibrations in the environment are usually distributed over a wide frequency spectrum in multiple directions and a weaker amplitude, which makes most of the current vibrational energy collectors ...limited in practical environmental applications. Herein, a triboelectric–electromagnetic hybridized nanogenerator (TEHG) for low-frequency random microvibrational energy harvesting in all directions and a wide working bandwidth is fabricated. The output peak power of a triboelectric nanogenerator (TENG) up to 3.65 mW is realized (θ = 0.4 rad, f = 1 Hz). In addition, a real self-powered seawater splitting system and electrochemical cathodic protection system are fabricated, directly converting blue energy to hydrogen energy, and the ships can achieve self-protection against corrosion. Furthermore, relying on the linear relationship between the number of peaks and the amplitude of vibration, a highly sensitive self-powered vibration amplitude sensor system based on LabVIEW software is achieved, which can be used as an amplitude detection of bridges and earthquake monitoring, etc. This work is an important development for harvesting low-frequency random multiple direction microvibrational energy over a wide working bandwidth and the bright future of blue energy. In addition, it has been successfully applied to the power supply of portable electronic equipment, environmental monitors, and self-powered systems.
Converting ubiquitous ambient low‐grade thermal energy into electricity is of great significance for tackling the fossil energy shortage and environmental crisis but poses a considerable challenge. ...Here, a novel thermal‐driven triboelectric nanogenerator (TD‐TENG) is developed, which utilizes a bimetallic beam with a bi‐stable dynamic feature to induce continuous mechanical oscillations, and the mechanical motion is then converted into electric power using a contact‐separation TENG. The thermal process inside the device is systematically investigated and effective thermal management is conducted accordingly. After optimization, the TD‐TENG can produce a power density of 323.9 mW m−2 at 59.5 °C, obtaining the highest record of TENG‐based thermal energy harvesters. Besides, the first prototype of TENG‐based solar thermal harvester is successfully demonstrated, with a power density of 364.4 mW m−2. Moreover, the TD‐TENG can harvest and dissipate the heat at the same time, exhibiting great potential in over‐heated electronics protection as well as architectural energy conservation. Most importantly, the operation temperature range of the TD‐TENG is tunable by adjusting the bimetal parameters, allowing the device a wide and flexible working thermal gradient. These unique properties validate the TD‐TENG is a simple, feasible, cost‐effective, and high‐efficient low‐grade thermal energy harvester.
An innovative thermal‐driven triboelectric nanogenerator (TD‐TENG) has been developed to harvest low‐grade thermal energy and solar thermal energy, which can be operated over a broad and flexible temperature range with ideal performance. Additionally, the TD‐TENG is an efficient heat sink that not only works without consuming energy but also generates electricity.
The energy conversion efficiency of conventional binary dielectric triboelectric nanogenerators is not satisfactory due to the limitations of material selection and triboelectrification, which ...motivates the design of more efficient multicomponent structures to reveal the charge accumulation mechanism for improving the energy conversion efficiency. Herein, a rotating quaternary dielectric triboelectric nanogenerator (Q-TENG) is designed to construct a self-powered system integrating illumination, sensing, and electrochemical decolorization. Through the equivalent capacitance model, the mechanisms for charge generation, transfer, and accumulation in a Q-TENG are elucidated to achieve efficient matching of quaternary dielectric materials and high output performance. At a wind speed of 3.5 m s–1, the peak power density of the Q-TENG reaches 44.94 W m–2, setting a new record for a wind-driven TENG. A 5 ppm solution of methyl orange is completely degraded by the wind-driven Q-TENG in <6 h. This work not only guides the direction for constructing more efficient TENG systems but also promotes the practical development of self-powered electrochemical systems.
Nowadays, the development of direct current triboelectric nanogenerators (DC‐TENGs) is oriented toward practical applications such as real‐time efficient harvesting and supplying energy. This demands ...DC‐TENGs with a low loss factor, high energy utilization efficiency, device portability, and output stability. Herein, a constant‐voltage DC‐TENG (C‐DC‐TENG) with robust output performance, using the ternary dielectric triboelectrification effect is demonstrated, which gives a crest factor of 1.0082. The key to improving the output charge density is the number of subdivision units, a result of theoretical simulations and experiments of C‐DC‐TENG. The optimized C‐DC‐TENG achieves not only an output charge density of 3.902 mC m−2 per round but also an average power density of 8.77 W m−2 (3.508 W m−2 Hz−1), which both set a new record for the rotary DC‐TENG. Moreover, introducing soft polyester fur enables C‐DC‐TENG to maintain 100% output without wear after 800 000 cycles. This C‐DC‐TENG is faultlessly competent for powering 2784 LEDs in series and 25 parallel‐connected hygrothermographs continuously. This work provides a promising technique for large‐scale clean energy harvesting, accelerating the progress toward practical applications of DC‐TENG.
A constant‐voltage DC‐triboelectric nanogenerator (C‐DC‐TENG) is constructed based on the ternary dielectric triboelectrification effect, achieving high average power density, high output charge density, high stability, and low crest factor (1.0082), and its superior and sustained output properties are expected to greatly accelerate the process of utilizing TENG for large‐scale energy harvesting.
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