A Triboelectric Nanogenerator Based on Sodium Chloride Powder for Self-Powered Humidity Sensor

Recently, the research of distributed sensor networks based on triboelectric technology has attracted extensive attention. Here, we reported a new triboelectric nanogenerator based on sodium chloride powder (S-TENG) to obtain mechanical energy. The polytetrafluoroethylene (PTFE) film and sodium chloride powder layer serve as the triboelectric pair. After testing and calculation, the internal resistance of S-TENG is 30 MΩ, and the output power of S-TENG (size: 6 cm × 6 cm) can arrive at the maximum value (about 403.3 µW). Furthermore, the S-TENG can achieve the open circuit voltage (Voc) of 198 V and short-circuit current (Isc) of 6.66 µA, respectively. Moreover, owing to the moisture absorption of sodium chloride powder, the S-TENG device also has the function of the humidity sensor. This work proposed a functional TENG device, and it can promote the advancement of self-powered sensors based on the TENG devices

A Novel Triboelectric Material Based on Deciduous Leaf for Energy Harvesting

Recently, the triboelectric nanogenerator (TENG) for harvesting low-frequency energy has attracted the attention of academia. However, there are few studies on environmentally friendly triboelectric materials. Here, we propose a novel triboelectric nanogenerator based on the deciduous leaf (DL-TENG) that can harvest mechanical energy from various low-frequency motions. The deciduous leaf is an environmentally friendly triboelectric material, which has a low-cost and is easy to obtain. Using it to generate electricity can achieve the effect of waste utilization. From the experimental results, the peak value of the short-circuit current (Isc) and the open-circuit voltage (Voc) can reach 4.2 µA and 150 V, respectively. The fabricated DL-TENG exhibits a stable high performance, with a maximum output power of 72.2 µW, to a load of 20 MΩ. Moreover, we also designed a stacked structure, DL-TENG, to enhance the electrical output. Additionally, the stacked DL-TENG could drive 15 commercial light-emitting diodes (LEDs). This design will promote the development of low-cost and environmentally friendly triboelectric material

A Novel Switched-Capacitor Inverter with Reduced Capacitance and Balanced Neutral-Point Voltage

A novel three-phase switched-capacitor multilevel inverter (SCMLI) with reduced capacitance and balanced neutral-point voltage is proposed in this paper. Applying only one DC source, the three-phase seven-level topology possessing voltage-boosting capability is accomplished without the high-voltage stress of power switches. Owing to the inherent redundant switching states of the proposed topology, two charging approaches that can effectively limit the voltage ripples and path selection for capacitors can be realized. This provides the presented topology with reduced capacitance, balanced neutral-point voltage, good performance in not only the three-phase four-wire system but also the three-phase three-wire system, and low total harmonic distortion (THD) of the output voltage. A comprehensive comparison with previous SCMLIs in various aspects is conducted to validate the merits mentioned above. The simulation results accord with theoretical analyses, confirming the feasibility of the proposed three-phase SCMLI

Pt Cluster Modified h-BN for Gas Sensing and Adsorption of Dissolved Gases in Transformer Oil: A Density Functional Theory Study

Hexagonal-Boron nitride nanotubes (h-BN) decorated with transition metals have been widely studied due to their enhanced physicochemical properties. In this paper, Pt cluster-modified h-BN is proposed as a sensitive material for a novel gas sensor for the online malfunction monitoring of oil-immersed transformers. The inner oil is ultimately decomposed to various gases during the long-term use of oil-immersed transformers. Exposure to excessively high temperatures produces the alkanes CH4 and C2H6, whereas different degrees of discharge generate H2 and C2H2. Therefore, the identification of H2, CH4, and C2H2 gas efficiently measures the quality of transformers. Based on the density functional theory, the most stable h-BN doped with 1–4 Pt atoms is employed to simulate its adsorption performance and response behavior to these typical gases. The adsorption energy, charge transfer, total density of states, projected density of states, and orbital theory of these adsorption systems are analyzed and the results show high consistency. The adsorption ability for these decomposition components are ordered as follows: C2H2 > H2 > CH4. Pt cluster-modified h-BN shows good sensitivity to C2H2, H2, with decreasing conductivity in each system, but is insensitive to CH4 due to its weak physical sorption. The conductivity change of Ptn-h-BN is considerably larger upon H2 than that upon C2H2, but is negligible upon CH4. Our calculations suggest that Pt cluster modified h-BN can be employed in transformers to estimate their operation status

A Novel Triboelectric Material Based on Deciduous Leaf for Energy Harvesting

Recently, the triboelectric nanogenerator (TENG) for harvesting low-frequency energy has attracted the attention of academia. However, there are few studies on environmentally friendly triboelectric materials. Here, we propose a novel triboelectric nanogenerator based on the deciduous leaf (DL-TENG) that can harvest mechanical energy from various low-frequency motions. The deciduous leaf is an environmentally friendly triboelectric material, which has a low-cost and is easy to obtain. Using it to generate electricity can achieve the effect of waste utilization. From the experimental results, the peak value of the short-circuit current (Isc) and the open-circuit voltage (Voc) can reach 4.2 µA and 150 V, respectively. The fabricated DL-TENG exhibits a stable high performance, with a maximum output power of 72.2 µW, to a load of 20 MΩ. Moreover, we also designed a stacked structure, DL-TENG, to enhance the electrical output. Additionally, the stacked DL-TENG could drive 15 commercial light-emitting diodes (LEDs). This design will promote the development of low-cost and environmentally friendly triboelectric material