Paper-based Triboelectric Nanogenerator Research Articles

Papermaking-inspired sustainable triboelectric sensors for intelligent detecting system

Digitalization not only drives the intelligent transformation of industries while fostering cultural diversity and innovation. Cutting-edge triboelectric sensing technology inspired by traditional Chinese papermaking fabricates a bamboo paper-based triboelectric nanogenerator (BP-TENG). The addition of high-purity bacterial cellulose improves the structural integrity of the resulting paper. The proposed BP-TENG exhibits excellent electrical performance, generating an output voltage of 88 V and a maximum output power of 0.9 mW at a low-frequency motion of 2 Hz. Moreover, the BP-TENG is combined with machine learning algorithms to build a multi-scene intelligent detecting system, including real-time handwriting-to-speech conversion, personalized jump prediction and smart home automation systems. The machine learning algorithm can achieve a recognition accuracy of up to 99.8 %. This multi-scene intelligent detecting system boasts superior accuracy, environmental sustainability and affordability, ideal for communication security, sports health monitoring and smart building applications.

Free-standing graphene oxide/carboxymethyl cellulose paper-based triboelectric nanogenerator for self-powered motion sensor

Triboelectric nanogenerators (TENG) are innovative energy-harnessing devices that serve as potential power sources for small portable electronics, operating on the principle of electrostatic induction. In this study, we demonstrate the fabrication of paper-like flexible graphene oxide/carboxymethyl cellulose (GO/CMC) composite film and their use as a tribo-positive layer in the TENG with fluorinated ethylene propylene (FEP) film as the tribo-negative layer. The GO/CMC TENG possesses high-energy harvesting performance compared to the bare CMC-based TENG that is due to the increase in surface charge of CMC due to the inclusion of GO sheets, as analyzed using Kelvin probe force microscopy (KPFM). The GO/CMC TENG device demonstrates an output voltage of 97 V and a short-circuit current of 1.2 µA, achieving a peak power of 41.4 µW, notably higher compared to state-of-the-art TENG devices. As a proof-of-concept, we also demonstrated the practical applicability of the GO/CMC TENG in day-to-day life for monitoring the human body motions and to drive portable electric devices, which ensures their candidature towards next-generation self-powered systems.

Structure-Foldable and Performance-Tailorable PI Paper-Based Triboelectric Nanogenerators Processed and Controlled by Laser-Induced Graphene.

Laser-induced graphene (LIG) technology has provided a new manufacturing strategy for the rapid and scalable assembling of triboelectric nanogenerators (TENG). However, current LIG-based TENG commonly rely on polymer films, e.g., polyimide (PI) as both friction material and carbon precursor of electrodes, which limit the structural diversity and performance escalation due to its incapability of folding and creasing. Using specialized PI paper composed of randomly distributed PI fibers to substantially enhance its foldability, this work creates a new type of TENG, which are structurally foldable and stackable, and performance tailorable. First, by systematically investigating the laser power-regulated performance of single-unit TENG, the open-circuit voltage can be effectively improved. By further exploiting the folding process, multiple TENG units can be assembled together to form multi-layered structures to continuously expand the open-circuit voltage from 5.3 to 34.4Vcm-2, as the increase of friction units from 1 to 16. Last, by fully utilizing the unique structure and performance, representative energy-harvesting and smart-sensing applications are demonstrated, including a smart shoe to recognize running motions and power LEDs, a smart leaf to power a thermometer by wind, a matrix sensor to recognize writing trajectories, as well as a smart glove to recognize different objects.

Sustainable paper-based triboelectric nanogenerator with improved output performance through a general strategy of interface fusion

The paper-based triboelectric nanogenerators (PB-TENGs) satisfied the requirement of sustainability and aroused great research interests, however how to improve their outputs still remains as a huge challenge. Most of the reported strategies to enhance the performance of PB-TENG focused on the chemical modification of the friction layers (FL), which may be restricted by the high-cost and cumbersome protocols being required. In this work, a general strategy of interface engineering to boost the outputs of the PB-TENG was proposed and validated by employing graphene composite paper (GC-paper) as electrodes. At the beginning, the hydroxyethyl cellulose (HEC) and Ecoflex were cured as separated films and used as friction layers, which were adhered with copper or GC-paper electrodes. The PB-TENG device can be obtained and possesses acceptable performance. Subsequently, we were surprised to find that the outputs of the PB-TENG largely increased by coating the FLs on the GC-paper rather than adhering. The maximum open-circuit voltage jumped from 300 V to 734 V, and the maximum short-circuit current boosted from 3.4 µA to 8.7 µA. This phenomenon may be ascribed to an interface effect between the FLs and electrodes, which enhanced the electrostatic induction. The strategy of this interface engineering was also proved to be general for other PB-TENG devices with various friction materials. Therefore, it may pave a way for the development of sustainable TENG devices with high performance.

Using Natural Dye Additives to Enhance the Energy Conversion Performance of a Cellulose Paper-Based Triboelectric Nanogenerator.

Green and sustainable power sources for next-generation electronics are being developed. A cellulose paper-based triboelectric nanogenerator (TENG) was fabricated to harness mechanical energy and convert it into electricity. This work proposes a novel approach to modify cellulose paper with natural dyes, including chlorophyll from spinach, anthocyanin from red cabbage, and curcumin from turmeric, to enhance the power output of a TENG. All the natural dyes are found to effectively improve the energy conversion performance of a cellulose paper-based TENG due to their photogenerated charges. The highest power density of 3.3 W/m2 is achieved from the cellulose paper-based TENG modified with chlorophyll, which is higher than those modified with anthocyanin and curcumin, respectively. The superior performance is attributed not only to the photosensitizer properties but also the molecular structure of the dye that promotes the electron-donating properties of cellulose.

A Pedagogical Approach to Assemble and Characterize Paper-Based Triboelectric Nanogenerators

A Pedagogical Approach to Assemble and Characterize Paper-Based Triboelectric Nanogenerators

Mechanical robust paper-based triboelectric nanogenerator films

We have fabricated paper-based triboelectric nanogenerator (TENG) films that are composed of polydimethylsiloxane (PDMS) and copy paper. The Young’s modulus of the paper-based TENG film was approximately 807 MPa, which was 1500 times higher than that of the pure PDMS film with the same thickness. The output voltage of the TENG with the paper/PDMS film was comparable to that of the PDMS film. The maximum power density of the TENGs with the paper/PDMS film was 181 μW cm−2. Furthermore, we demonstrated luminescence of 54 LEDs using the TENG with the paper/PDMS film.

Preparation of micro-fibrillated cellulose fibers by a simple two-step refining process for paper- based flexible electronic devices

Cellulose micro/nano-materials are potential substrates for energy storage/ electronics applications. However, developing efficient/cost-effective technologies that can obtain these micro/nano-materials suited for flexible electronics continue to be a challenge. In this study, we report a simple process for extracting micro-fibrillated cellulose fibers from conventional bleached kraft pulp that are particularly applicable to flexible electronics applications. The process is made of two step refining: 1) refining in a Valley beater, and 2) further fibrillation in a ball mill. The Valley beater is to induce fibrillation of pulp fibers as a result of compression and shearing forces. Subsequently, the partially fibrillated cellulose fibers are further subjected to ball milling to obtain micro-fibrillated cellulose fibers (MFCs). These MFCs have a much higher specific surface area than the conventional pulp fibers due to fibrillation and reduction in fiber size, which leads to favorable properties to the as- prepared MFCs network, including high transparence, and high tensile strength. The MFCs paper exhibits excellent transparency of 82% at 550 nm (a significant increase of about 56% for the control), with exceptionally high tensile strength (35.16 MPa). Thanks to the high surface area of these MFCs, silver nanowires (AgNWs) can be well distributed into the MFCs network so that conductive paper with high conductivity was prepared. The MFCs/AgNWs composite paper was then assembled into the paper-based triboelectric nanogenerator (P-TENG) device, which shows excellent performance. The MFCs/AgNWs composite paper- based P-TENG system can also serve as self-powered sensors for monitoring human motions. This work provides a method for the production of micro- fibrillated cellulose fibers that can be applied for the production of flexible electronic devices.

Design and Development of Paper/ZnO–SnO2 Heterostructured Ultra-Fast TENG Based LPG Sensor

This work establishes a very simple and economical preparation of paper-based triboelectric nanogenerators for self-powered LPG sensing. Magnification in the output of TENG was achieved by ZnO/SnO2 synthesized by hydrothermal. This material has been thoroughly characterized through XRD, UV, FESEM, FTIR, and Nanozetasizer. The average crystallite size of the heterostructure was obtained as 17.59 nm. Bandgap of ZnO/SnO2 material was found as 3.49 eV. FESEM exhibits that present heterostructure material exhibits spherical nature with lots of voids on the film surface. From Nanozetasizer, the diameter of particles resides between the range 50–80 nm with an average particle size as 63.23 nm. The fabricated TENG generates a maximum output voltage of ∼75 volts which is more than the output of paper-based TENG. This TENG was used as a power source to operate a resistive LPG sensing film. The maximum response of 24 and minimum response-recovery times of 120–135 ms were observed, which makes this LPG sensing device ultra-fast.

Sisal cellulose paper based triboelectric nanogenerator with high performance for detection of chemical group substitution degree

Cellulose-derived materials have attracted extensive attention for applications in advanced electronics due to their abundance, low cost, light weight, and sustainability. Here, we report a paper-based triboelectric nanogenerator (TENG) which was made of sisal cellulose as the friction layer. The effects of the surface morphology, structure, and dielectric properties of sisal cellulose paper (SCP) on the output performance of SCP-TENG were discussed. It is found that the electrical output performance of the SCP-TENG can be improved and controlled by chemically modifying SCP with different polar groups of -NO2, -COCH3, -Cl, -Br, -CH3, -C2H5, which is closely related to the dielectric constant change of SCP. Among them, the dielectric constant of the nitrated SCP is the highest, and the electrical output performance of the corresponding SCP-TENG also exhibits the highest, with the short-circuit current, open-circuit voltage, charge and power density improving to 20.78 μA, 198 V, 103 nC/m2, 827.03 mW/m2, from 6.13 μA, 118 V, 53 nC/m2, and 256.97 mW/m2, respectively. Based on the linear relationship between the current intensity of the modified SCP-TENG and the degree of substitution of different groups, a chemical sensor for detecting the degree of group substitution was successfully fabricated. This work provides a new idea for broadening the application field of TENG.

Acid- and Alkali-Resistant and High-Performance Cellulose Paper-Based Triboelectric Nanogenerator by Controlling the Surface Hydrophobicity

Cellulose paper-based triboelectric nanogenerators (CPTENGs) have gained considerable attention because they are low-cost, lightweight, flexible, and environmentally friendly. However, the poor triboelectric property and hydrophobicity of cellulose paper still limit the development of high-performance CPTENGs. In this work, octadecylamine (ODA) has been introduced onto cellulose fibers to prepare hydrophobic cellulose paper (HCP) by means of polydopamine (PDA) which can react with ODA and hydrogen bond with cellulose. Benefiting from the ODA and PDA co-modification, HCP exhibits excellent triboelectric property, surface roughness, and hydrophobicity; moreover, the HCP exhibits remarkable resistance to acids and alkalis. In addition, an HCP-based TENG (HCPTENG) shows an open-circuit voltage (VOC) of 237.8 V and a short-circuit current (ISC) of 4.2 μA, which are higher than those of the most of cellulose paper-based TENGs. More importantly, the HCPTENG shows great output performance stability when treated with water, acids, and alkalis. The HCPTENG with a retractable and collapsible lantern structure can harvest energy from human movement and detect the foot motion like walking and running and hand flapping.

Paper-based triboelectric nanogenerator and activities of salt ions

This work presents a triboelectric nanogenerator (TENG) fabrication using polytetrafluoroethylene, aluminum foil, and cellulose paper. Mechanical interactions lead to atomic defects that stimuli the delocalized electrostatic charge carriers and kinetic energy. The addition of ionic salt’s microdroplets improved the TENG’s performance. Eventually, surface charge activities have escalated the electrical signals. Further, studied spontaneously increased charge transport performance at the steady-state condition in the presence of NaCl ionic droplets. We considered that these ionic activities actively participated in detecting salt ions.

Barium titanate dielectric regulation improved output performance of paper-based triboelectric nanogenerator

As a new energy conversion device that can convert mechanical energy into electrical energy, triboelectric nanogenerator has attracted extensive attention since its invention. However, its environmental performance is limited because the raw materials are mostly synthetic polymer materials. Using green and environmentally friendly cellulose materials to prepare triboelectric nanogenerators is one of the important ways to solve the above problems. In this study, cellulose/barium titanate composite paper is prepared by using bamboo cellulose and barium carbonate (BaTiO<sub>3</sub>) as raw materials and combining wet papermaking and doping modification. The paper based triboelectric nanogenerator (C/BT-TENG) is constructed by using the cellulose/barium titanate composite paper as a positive friction layer. The results show that the addition of BaTiO<sub>3</sub> significantly improves the relative dielectric constant of the composite paper, and the output performance of C/BT-TENG increases with the augment of BaTiO<sub>3</sub> doping amount. When the doping amount is 4%, the open-circuit voltage and short-circuit current of C/BT-TENG reach the maximum values of 118.5 V and 13.51 µA, respectively, which are 51.3% and 41.2% higher than when pure cellulose paper is used as the positive friction layer. The mechanism of dielectric regulation to improve the C/BT-TENG output performance is analyzed by the modeling method. In addition, the C/BT-TENG has a good output performance and operation stability. When the load resistance is 5 MΩ, the maximum output power density of C/BT-TENG reaches 0.36 W/m<sup>2</sup>, simplying a good application prospect.

Fabrication of polyethyleneimine-paper composites with improved tribopositivity for triboelectric nanogenerators

Significant progress has been made in the fabrication of paper-based triboelectric nanogenerators (TENGs) through the increase of the electron-donating ability of cellulose paper. However, challenges still exist in the mass production of cellulose-based tribopositive materials with high output performance. Herein, a facile method was developed to improve the tribopositive performance of cellulose paper by simply loading branched polyethyleneimine (PEI). By changing the loading weight of PEI, PEI-paper composites with different structures and mechanical properties were prepared. The PEI-paper composites show drastically improved triboelectric output performance with an increasing loading weight of PEI because of their sharply increased relative permittivity. By loading 7.5 mg/cm2 PEI to form a network structure and loading 22.5 mg/cm2 PEI to form a hydrogel-like structure, the triboelectric output performances of the formed PEI-paper composite-based TENG are increased by approximately 4 and 6 times, respectively, and their power densities are increased by approximately 7.5 and 16 times, respectively. The PEI-paper composite-based TENG can serve as a self-powered pressure sensor to sense different external stimuli under different working modes and construct self-powered electric skin. Meanwhile, the occurrence of PEI also confers PEI-paper composites with water resistance, antibacterial activity, and flame retardation, yet the disposability of the paper remains. This work provides a simple method for improving the triboelectric performance of cellulose paper.

An environmentally friendly reusable triboelectric nanogenerator based on instant noodle powder

Recently, paper-based triboelectric nanogenerators (TENGs) have been attracting increasing attention. This interest is driven by desirable features such as affordability, environmental efficiency, and sustainable energy harvesting. This study investigated instant noodles powder as a novel and innovative triboelectric material for constructing a TENG (INPP-TENG). Triboelectric pairs were developed using instant noodles powder and PTFE tape, and paper served as the material of the supportive structure. The open circuit voltage (Voc) was 576 V, and the output power density was 326.7 μW/cm 2. The proposed TENG can be used to assess the relative humidity (RH) of the environment. The renewable utilization and quality of the proposed TENG were also investigated. A device with the dimensions of 4 cm × 6 cm generated an electrical output that could directly power 185 blue high-power LEDs. Moreover, the structure of an innovative Miura-folding-paper-based TENG is presented. In addition to harvesting mechanical energy from human activities, the proposed design also detects different touch states. This paper proposes a portable, light-weight, affordable, and multifunctional device for humidity detection and energy harvesting.

Cellulose Paper Modified by a Zinc Oxide Nanosheet Using a ZnCl2-Urea Eutectic Solvent for Novel Applications.

Cellulose paper has been functionalized by nanoparticles such as Ag nanoparticles, TiO2, and BaTiO3 for versatile applications including supercapacitor, sensors, photoactivity, and packaging. Herein, zinc oxide (ZnO) nanosheet-modified paper (ZnO@paper) with excellent antibacterial properties was fabricated via a mild ZnCl2-urea eutectic solvent. In this proposed method, cellulose fibers as the raw material for ZnO@paper were treated by an aqueous solvent of ZnCl2-urea; the crystalline region was destroyed and [ZnCl]+-based cations were adsorbed on the surface of cellulose fibers, facilitating more ZnO growth on ZnO@paper. A flexible paper-based triboelectric nanogenerator (P-TENG) was made of ZnO@paper paired with a PTFE film. The P-TENG presents high triboelectric output performance and antibacterial activity. For instance, the output voltage and current of the P-TENG were 77 V and 0.17 μA, respectively. ZnO@paper showed excellent antibacterial activity against E. coli and S. aureus, suggesting that a P-TENG can restrain and kill the bacteria during the working process. The results also indicated that ZnO could improve the surface roughness of cellulose paper, enhancing the output performance of a flexible P-TENG. In addition, the potential application of a P-TENG-based pressure sensor for determining human motion information was also reported. This study not only produced a high-performance P-TENG for fabricating green and sustainable electronics, but also provides an effective and novel method for ZnO@paper preparation.

Paper-based triboelectric nanogenerators and their applications: a review.

The development of industry and of the Internet of Things (IoTs) have brought energy issues and huge challenges to the environment. The emergence of triboelectric nanogenerators (TENGs) has attracted wide attention due to their advantages, such as self-powering, lightweight, and facile fabrication. Similarly to paper and other fiber-based materials, which are biocompatible, biodegradable, environmentally friendly, and are everywhere in daily life, paper-based TENGs (P-TENGs) have shown great potential for various energy harvesting and interactive applications. Here, a detailed summary of P-TENGs with two-dimensional patterns and three-dimensional structures is reported. P-TENGs have the potential to be used in many practical applications, including self-powered sensing devices, human–machine interaction, electrochemistry, and highly efficient energy harvesting devices. This leads to a simple yet effective way for the next generation of energy devices and paper electronics.

Punching pores on cellulose fiber paper as the spacer of triboelectric nanogenerator for monitoring human motion

As a new type of energy harvesting device, the triboelectric nanogenerator (TENG) can convert mechanical energy into electrical energy effectively. Paper-based materials have gained considerable attention for use in flexible energy harvesting device applications because of their flexibility, environmental friendliness (i.e., they are biodegradable and renewable), and foldability. This work proposes a strategy to use cellulose fibers layer as a spacer of paper-based triboelectric nanogenerator (P-TENG). The P-TENG consists of a three-layer fiber material and a copper electrode. The three-layer fiber material comprises nylon, cellulose, and polypropylene, where the cellulose fiber layer contains millimeter-sized holes and is used as a spacer. Because of its attractive cuttability and flexibility properties, the P-TENG can be applied on a large scale in complex environments (e.g., sports fields, driving training fields) to detect signal changes caused by external pressure This type of device has great potential for application to the large-scale TENG field and may provide a new solution for TENG industrialization.

Synthesis of bilayer MoS2 nanosheets by green chemistry approach and its application in triboelectric and catalytic energy harvesting

Recently, 2D materials are being explored as attractive candidate materials for mechanical energy harvesting by employing the triboelectric effect. However, in this work, development of flexible paper-based triboelectric nanogenerators has been reported in 2-, 5- and 9-layered MoS2 nanosheets (MNSs). The syntheses of bilayered MNSs have been carried out by using a rarely reported natural surfactant (aqueous extract of Washnut, viz.) assisted simple bath ultrasonication process. The development of triboelectric power cells (TPCs) by using bilayer MNSs has also not been reported earlier and it has been found that it is exhibiting the best performance. The maximum values of open-circuit voltage (Voc) and power density of ∼10.20 V and ∼2.55 mW/m2, respectively, are obtained in bilayer MNSs based TPC. It is found that the fabricated device can charged up an external capacitor up to the maximum voltage of 0.52 V within 25s. Also, due to the highest absorbance of bilayer MNSs in the visible region, it has been found to be acting as the most effective photocatalytic material for removal of MB dye from water even under the visible light excitation. In another experiment, the bilayer MNSs is found to be exhibiting superior catalytic activity in the hydrogen evolution reaction (HER), and the highest value of the Tafel slope for bilayer MNSs is obtained as ∼49 mV/decade. Thus, it is envisioned that this work will open up new vistas of easy and eco-friendly processes for synthesis of 2D MoS2 nanosheets for their potential applications in energy harvesting by using triboelectric and as well as catalytic processes.

A novel rhombic-shaped paper-based triboelectric nanogenerator for harvesting energy from environmental vibration

Triboelectric nanogenerator (TENG) as a promising energy harvesting technology attracts much attention in recent years. Among others, the contact mode TENG is often given priority by virtue of its reliable robustness and high energy conversion efficiency. However, in most cases, the contact-mode TENG is only suitable for collecting energy from pressure-induced incentives because it requires a compression forces to drive. Here, we propose a rhombic-shaped paper-based triboelectric nanogenerator (RP-TENG) that may operate effectively under tensile conditions together with an enhanced contact force between the tribo-pair induced by the design of pressurizing braces. Mechanical tests were carried out to investigate the output performance of the RP-TENG under the activation of various applied forces. An integrated RP-TENG with four tribo-pairs were fabricated for optimizing the output performance. The novel design facilitates the device to achieve higher energy conversion efficiency and also expand its application circumstances. A theoretical model is developed to establish the correlation between the output voltage of the RP-TENG and the geometric characteristics as well as external excitations. The results suggest an effective strategy of using paper-based rhombic-shape design to enhance contact-mode TENGs and may serve as a guideline for structural and circuit design of this novel TENG devices.