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The emergence of tribovoltaic nanogenerators (TVNGs) paves the way for developing a new kind of semiconductor‐based energy harvester that overcomes the restriction of low output current in a conventional approach. The traditional TVNG generally depends on the frictional pair between two rigid semiconductors (or metal‐semiconductor), limiting the practicability of flexible and portable electronics. Recent developments require the fundamental understanding of charge generation in diverse operating modes and structures. Here, a flexible TVNG based on the p‐Cu2O/n‐g‐C3N4 interface is presented. Operating in a freestanding mode, the proposed TVNG can generate a stable signal in any optical conditions including UV illumination, dark, and ambient. Under UV illumination, the electrical outputs of the TVNG reach 0.43 V and 2.1 µA cm−2, which are significantly larger than those obtained from dark and ambient conditions. The results demonstrate the coupling effect of three phenomena: tribovoltaic, photovoltaic, and triboelectric effects, and the unique mechanism to the observed signal is proposed. Additionally, the TVNG shows the practical feasibility of energy harvesting with capacitor charging and charge‐boosting circuits. This study showcases the unique concept with potential for developing a novel flexible nanogenerator in many aspects, including material, structure, and fundamental mechanism. [ABSTRACT FROM AUTHOR]

There is a need to develop inexpensive, lightweight, and flexible high‐performance triboelectric nanogenerators (TENGs) from renewable resources. Here, a multifunctional cellulose filter paper (CFP)‐based TENG consisting of dielectric Ti0.8O2 nanosheets (Ti0.8O2 NSs) and conducting Ag nanoparticles (Ag NPs) is prepared by a simple dip coating method. The incorporation of dielectric Ti0.8O2 NSs onto the CFP significantly improves charge generation, while the inclusion of Ag NPs provides an electrically conductive path for charge transportation. The presence of these fillers can be deduced from XRD, SEM, EDS, X‐ray photoelectron spectroscopy, and Raman spectroscopy. Their distribution is visualized in 3D by synchrotron radiation X‐ray tomography. The present CFP‐based TENG provides an output voltage and current density of ≈42 V and ≈1 µA cm−2, respectively with the power density of ≈25 µW cm−2. It is capable of lighting up 40 light‐emitting diode bulbs and charging a 0.22 µF capacitor to 8 V in only 5 s. The developed TENG is also capable of detecting simple human motions, i.e., finger tapping, finger rubbing, and foot trampling. This work offers a facile design of low cost yet efficient paper‐based TENG by dual modification with multifunctional nanomaterials, and also demonstrates its use as a feasible power source that not only drives small electronics, but also scavenges energy from human actions. [ABSTRACT FROM AUTHOR]

The flexible piezoelectric nanocomposites based on lead magnesium niobate titanate [Pb(Mg1/3Nb2/3)0.65Ti0.35O3; PMNT] particles in polydimethylsiloxane (PDMS) matrix were fabricated and characterized. PMNT powders are synthesized using the columbite precursor method. PMNT/PDMS flexible nanocomposites are then prepared by spin casting technique, where a small amount of carbon nanotubes (CNTs) is added into the PMNT/PDMS composite to enhance cross-links between PMNT particles and PDMS matrix. The phase and microstructure of the nanocomposite are investigated by using X-ray diffraction and scanning electron microscope (SEM). The electromechanical behavior is evaluated by using an autonomous pneumatic actuator. The flexible composite, occupying approximately 300 mm2, is capable of generating an open-circuit voltage (Voc) of 2.83 ± 0.24 V and a short-circuit current (Isc) signal of 0.33 ± 0.01 µA across 10 Ω resistor under mechanical load of 300 N. The generated electrical charges are 29026 pC. The relative dielectric constant is measured at 10 kHz and found to be 6.76 ± 1.15. The piezoelectric PMNT/PDMS composite can potentially be used in a variety of applications such as wearable sensors, actuators, and energy harvesting for converting kinetic energy into useful electrical energy. [ABSTRACT FROM AUTHOR]

The explosive development of triboelectric nanogenerator (TENG) performance, with a simple structure and low cost, has become an excellent candidate for a primary self-powered source of portable modern-electronic devices. There are several approaches to booting TENG performance. However, some of them still encounter major challenges when fabricating a lightweight, flexible and scalable design. Herein, three main strategies; 1) structural design with 3D multi-layer Origami structure, 2) physical surface roughness modification, and 3) connection of a self-charge pumping module (SCPM) were selected and considered in terms of cheapness, light weight and scalability, with a simple manufacturing process. By optimizing these three strategies, the 3D multi-layer Origami TENG (O-TENG) can achieve an output performance of V OC ~ 110 V and I SC ~ 26 μA , which is 18 and 52 times higher than that for the non-optimized polyimide (PI) TENG, respectively. The output voltage demonstrates consistency and fast chargeability of ∼38 V saturation voltage within ∼8 s for a 0.22 μF capacitor. The maximum of ~ 697 μW output power (P) could be provided at 10 MΩ. The number of origami layers (n) plays an important role in output performance, while integrating an SCPM module that accelerates chargeability of the device. Moreover, the cylindrical pocket energy harvesting device was designed to harvest biomechanical energy in daily life. One hundred and seventy light emitting diodes (LEDs) can be lit and the electric calculator driven easily. The proposed strategies have the potential for high-throughput fabrication of the low-cost TENG, and can be used simply as an alternative self-powered source for portable/wearable modern electronic devices. [Display omitted] • Three simple strategies for enhancing TENG performance was proposed under a cost-effective fabrication process. • Scalable, lightweight of flexi-TENG using Origami-inspired designs was successfully fabricated. • The 3D multi-layer Origami TENG (O-TENG) can achieve an output performance of ~697 μW at 10 MW under the tropical area condition. • The O-TENG attained fast chargeability of ~38 V within ~8 seconds under the tropical area condition. [ABSTRACT FROM AUTHOR]

• Enhancing the electrical output performance of a composite piezoelectric nanogenerator based on BCZT/MCNTs/PDMS through triboelectric hybridization. • The piezo-triboelectric nanogenerator, based on the BCZT/MCNTs/PDMS composite, demonstrated optimal electrical output performance at a 50 wt%-BCZT ratio (V OC ∼ 39.7 V, I SC ∼ 1.9 µA, peak-to-peak power of ∼ 157.7 µW, and power density of ∼ 9.85 µW/cm2) under a compressive load force of 500 N and a frequency of 1 Hz. • The piezo-triboelectric nanogenerator device exhibits promising potential for energy harvesting under high compressive loading at low frequencies. This work has developed a novel piezo-tribo-electric nanogenerator (P-TENG) that is capable of converting mechanical energy into electrical energy when operating in compressive mode. An arch-shaped P-TENG device was formed using an optimal piezoelectric polymer composite, which was fabricated using a polydimethylsiloxane (PDMS) matrix that was modified with piezoelectric (Ba 0.85 Ca 0.15) (Ti 0.90 Zr 0.10)O 3 (BCZT) ceramic particles and electrically conductive multi-walled carbon nanotubes (MCNTs). A high filler loading of BCZT (40, 50, 60 wt%) and 3 wt% of MCNTs was formed into a 0–3 connectivity composite. The P-TENG device containing 50 wt% BCZT exhibited the highest electrical output (V OC ∼ 39.7 V, I SC ∼ 1.9 µA, and maximum power ∼ 157.7 µW), compared to the other composites, when subjected to an alternating compressive load of 500 N at a 1 Hz frequency. This research provides new composite formulations for elastomeric-based energy generators that are responsive to low frequency mechanical oscillations. [Display omitted] [ABSTRACT FROM AUTHOR]

• NiFe 2 O 4 is synthesized by solid state reaction and flexible PDMS-NFO composite is formed. • The PN12 device produce voltage of 60 V and current of 300 nA. • X-ray tomographic microscopy images of PDMS-NFO composite is illustrated. • Smart home-based energy harvesting in daily life is demonstrated. Energy harvesting technologies are becoming popular owing to their usage in the operation of low-power consumer electronics and as an alternative power source. Specifically, triboelectric nanogenerators (TENGs) have drawn much attention as they can efficiently scavenge waste mechanical energy into electrical output. Careful material selections can further improve the performance of TENGs. In this work, a spinel ferrite material with the chemical formula NiFe 2 O 4 (NFO abbreviated further) is synthesized using a solid-state reaction route. The structural and magnetic property of the NFO has been studied, showing the cubic symmetry and ferromagnetic nature of the sample. The 3D tomography images of the PDMS-NFO composites were carried out using X-ray tomographic microscopy. To enhance the performance of the TENGs, we adopted a porous media by evaporation of water during the curing process of PDMS-NFO composites. A single-electrode operating mode was adopted for TENG fabrication. The electrical response of the device was carried out using different wt% and frequencies. The 12 wt% of NFO in PDMS (PN12 device) delivered a voltage, current, and charge of 60 V, 300 nA, and 34 nC, respectively. The charge density of the plain and porous composite-based TENG was compared to confirm the enhancement of the charge produced on the triboelectric layers. The commercial capacitors and energy harvesting based on a smart home were demonstrated using the TENG devices. [ABSTRACT FROM AUTHOR]