Triboelectric nanogenerator (TENG) has a promising future in the field of energy harvesting and self-powered sensing due to their simplicity in structure, low cost, and efficient energy harvesting from the surrounding environment. The output electrical performance of TENG can be improved by doping the friction material with functional materials and modifying the surface of the friction material. However, the current method of adding functional materials to friction materials is costly and wasteful, and the method of modifying the surface structure of friction materials is cumbersome and not easy to operate. In this work, we present a polydimethylsiloxane (PDMS)-MXene/gelatin triboelectric nanogenerator (PMMG-TENG) based on petal surface-microstructures, which has the advantages of low cost, simple preparation, high output performance, and ecological friendliness. By doping 0.03 wt.% of MXene in PDMS, the output electrical performance of TENG can be significantly improved, with an output current increase of up to 139.7%. Four different petals are used as natural molds to prepare PMMG-TENG. The results show that PMMG-TENG with peony petal surface microstructure has the best electrical performance, and the output current increase of up to 228.17% compared with PMMG-TENG without structure. The PMMG-TENG with peony petal surface-microstructure exhibits excellent electrical performance, demonstrating a maximum open-circuit voltage of 417.39 V and a maximum short-circuit current of 12.01 µA at a size of 3 cm × 3 cm, and a maximum power density of 170 µW/cm² at a load resistance of 10⁷ Ω. The PMMG-TENG’s output performance after 10,000 cycles is consistent with the initial state, highlighting excellent output stability. The PMMG-TENG can easily light up at least 100 light emitting diodes (LEDs). (operating voltage 3V.) Gelatin film exhibits excellent degradation performance, with complete degradation time of only 150 s in water at a constant temperature of 75 °C. PMMG-TENG not only shows excellent performance in the field of energy harvesting, but also has a broad application prospect in the field of self-powered sensing. This work provides a simple, low cost, natural and green method to significantly improve the output electrical performance of TENG.

Wind energy as a renewable energy source is easily available and widely distributed in cities. However, current wind-energy harvesters are inadequate at capturing energy from low-speed winds in urban areas, thereby limiting their application in distributed self-powered sensor networks. A triboelectric–electromagnetic hybrid harvester with a low startup wind speed (LSWS-TEH) is proposed that also provides output power within a wide range of wind speeds. An engineering-implementable propeller design method is developed to reduce the startup wind speed of the harvester. A mechanical analysis of the aerodynamics of the rotating propeller is performed, and optimal propeller parameter settings are found that greatly improved its aerodynamic torque. By combining the high-voltage output of the triboelectric nanogenerator under low-speed winds with the high-power output of the electromagnetic generator under high-speed winds, the harvester can maintain direct current output over a wide wind-speed range after rectification. Experiments show that the harvester activates at wind speeds as low as 1.2 m/s, powers a sensor with multiple integrated components in 1.7 m/s wind speeds, and drives a Bluetooth temperature and humidity sensor in 2.7 m/s wind speeds. The proposed small, effective, inexpensive hybrid energy harvester provides a promising way for self-powered requirements in smart city settings.

With the development of society and the advancement of technology, the emergence of the Internet of Things (IoT) has changed people’s lifestyles and raised the demand for energy to a new level. However, there are some drawbacks in terms of energy supply for IoT sensors, such as limited battery capacity and limitations in replacement and maintenance. Therefore, it has become urgent to develop a sustainable green energy source (wind energy) using the surrounding environment. Meanwhile, triboelectric nanogenerators (TENGs) with advantages such as flexible structure, low manufacturing cost, and environmental friendliness provide enormous potential for constructing self-powered sensing systems. In this work, we present a novel coaxial rolling charge pump TENG (CR-TENG) based on wind energy to enhance the output performance and durability. The rolling friction charge pump TENG directly injects positive and negative charges into the main TENG, which is more wear-resistant compared to sliding friction, and greatly increases the charge density and output power. In addition, the charge pumping part and the main TENG adopt the coaxial design, reducing the complexity of the structural design. On comparing the output performance of the CR-TENG under the initial state, rectifier bridge supplemental charge strategy, and charge pump supplemental charge strategy, results shown that the output voltage performance of the CR-TENG can be improved by 5800% under the charge pump supplemental charge strategy. Moreover, the output performance of the CR-TENG remains stable after 72,000 cycles. The output power of the CR-TENG can reach 1.21 mW with a load resistance of 3 × 10⁷ Ω. And the CR-TENG can charge a 0.1 μF capacitor to 5 V in just 1.6 s. This work provides new insights for the rotary durable high output charge pump compensating a triboelectric nanogenerator and demonstrates the important potential of harvesting environmental energy to supply intelligent IoT nodes.

Rotary triboelectric nanogenerators have been widely used in the field of self-powering of the Internet of Things (IoT) as an effective way to capture the mechanical energy of the environment. However, the wear problem caused by long-term contact of friction materials seriously affects its durability in practical applications, which makes the output performance of the system decrease. In this paper, a multi-roller rotary triboelectric nanogenerator (MR-rTENG) based on charge pump strategy is proposed. By using rolling friction, the ambient mechanical energy can be converted into electrical energy with reduced friction resistance and material wear, while the non-contact design of the main TENG can effectively enhance the durability of the system. In addition, a charge pump supplemental charging strategy is introduced to greatly improve the output performance of the MR-rTENG. At 600rpm, the voltage, current and charge transfer reached 1785 V, 49 μA and 187 nC respectively, with a peak power of 36.38 mW and an effective contact area of only 8 cm². After 40,000 cycles, the output performance of MR-rTENG remains stable. It is able to charge a 10 μF capacitor to 10 V in 15 s and light up 174 LEDs. MR-rTENG has been demonstrated as a power source for hydrogen production from electrolyzed water, driving the production of high-purity hydrogen gas from electrolyzed water. Electrolyzing water to produce hydrogen is a green and environmentally friendly technology, but its high cost limits its large-scale application. The realization of the application of research on hydrogen production from electrolytic water driven by renewable energy has further reduced the cost and promoted the application and promotion of this green technology.