Vertical Contact-separation Mode Research Articles

Effective parameters on polydimethylsiloxane/graphene composite-based triboelectric nanogenerator performance

ABSTRACT This paper systematically investigates the effective parameter on the performance of polydimethylsiloxane/graphene (PDMS@Gr)-based triboelectric nanogenerators (TENGs) as well as their applications. PDMS@Gr films containing 0, 0.05, 0.5, 1, and 1.5 wt.% graphene are synthesized, and their surface characteristics, mechanical behavior, and electrical properties are characterized. Vertical contact-separation mode TENGs are fabricated, and their performance is evaluated. The results demonstrate that the surface roughness and surface charge density are the most critical parameters for the performance of PDMS@Gr-based TENGs compared to the electrical and mechanical properties of the friction layers. The PDMS@Gr-based TENG with 1 wt.% graphene shows the highest power output of 2.6 W/m2 at an optimized working condition (5 Hz and 15 N). It also exhibits stable power output until 15,000 working cycles and displays battery-free applications by powering a light-emitting diode (LED) array, a calculator, a digital watch, and a digital thermometer.

Polystyrene Waste-ZnO nanocomposite film for energy harvesting via hydrophobic triboelectric nanogenerator: Transforming waste into energy

This research aimed to generate electricity from polystyrene waste materials combined with zinc oxide (ZnO) nanomaterials. Developing alternative polystyrene waste materials for generating electricity in triboelectric nanogenerator (TENG) could be beneficial in a circular economy and sustainable development. With the motivation to reduce environmental pollution by using polystyrene waste, a recycled polystyrene-ZnO nanocomposite film (rPS-ZnO NF) was synthesized and served as a triboelectric material for energy harvesting applications. ZnO nanopowder was produced by a low-temperature solution immersion method in conjunction with a simple film-casting method to prepare the rPS-ZnO NF. The effects of varying amounts of toluene as a solvent medium and the immersion time in stearic acid (SA) solution treatment on the structural properties, wettability behavior, surface morphology, chemical bonding properties, surface characteristics, and TENG performance were investigated. In this work, rPS film, rPS-ZnO NF, and SA-treated rPS-ZnO NF were paired with Kapton film as the opposite triboelectric material in constructing the vertical contact-separation mode TENG. Compared to rPS TENG, the rPS-ZnO TENG exhibited a two-fold enhancement in performance (8.2 V) in output voltage and ∼4.5 fold enhancement (28.1 μW/cm2) in power density. Furthermore, following SA treatment, the triboelectric performance further improved, reaching the highest open circuit voltage of ∼8.8 V and the highest power density of 32.0 μW/cm2 for repeated 2 N-solenoid tapping force. The hydrophobic behavior was also improved with the highest water contact angle of 134.7 (when the SA treatment immersion time was 1 h). These findings demonstrate that SA-treated rPS-ZnO NF could be a promising candidate for efficient mechanical energy harvesting with high electrical output and excellent surface wettability. This research not only exhibits an excellent output performance of SA-treated rPS-ZnO TENG, but it also sheds new light on the sustainable approach of converting polystyrene waste into energy-harvesting material.

Boron Minerals with Different Crystal Structures as Performance Manipulators in Triboelectric Nanogenerators

Triboelectric nanogenerators (TENGs) are energy generation devices that naturally convert mechanical movements into electrical energy through both triboelectric and electrostatic effects. The electricity generation capacity of silicone/boron minerals‐based composite and glass fiber‐based vertical contact separation mode TENGs enhances by adjusting the triboelectrification characteristics by embedding natural boron minerals (NBO) such as borax, colemanite, and ulexite additives. Considering the generated voltages, the NBO‐doped silicone and glass fiber‐based TENGs offer the maximum performance with 2.5 wt% borax, 7.5 wt% colemanite, and 5 wt% ulexite. The highest power density of corresponding NBO‐doped silicone glass fiber TENGs finds as 25.4, 26.03, and 32.03 W m−2, respectively. This work demonstrates that using boron significantly improves the TENG's power and charging capacities fabricated with silicone and glass fiber. Thus, the clean and safe generation of energy will contribute to the reduction of fossil fuel consumption and help protect the environment.

Antimony Sulfoiodide‐Based Energy Harvesting and Self‐Powered Temperature Detection

The ferroelectric‐semiconductor behavior of antimony sulfoiodide (SbSI) has opened up the material as a base for energy‐harvesting devices. Specifically, SbSI has drawn much attention for pyroelectric energy harvesting and thermal sensing with outstanding electrothermal properties. This work investigates the thermistor properties of an SbSI material and presents the development of an SbSI nanorod/Kapton‐based triboelectric nanogenerator (TENG) for effective energy harvesting and temperature sensing. The TENG based on SbSI/ Kapton operating in vertical contact separation mode delivers a peak‐to‐peak voltage of 90 V and a current of 1510 nA, respectively. Introducing SbSI nanorods for TENG opens the possibility of extending the conventional triboelectric series. The electrical and dielectric properties of the SbSI nanorods are investigated. SbSI exhibits a highly linear temperature coefficient of resistance (TCR) of −0.026 °C−1, making it an excellent candidate material for a thermistor. In addition, the material exhibits an excellent thermal sensitivity (β20/80 = 1612.1 K). For demonstration, the SbSI thermistor is connected with TENG, and the outputs at various temperatures are analyzed for self‐powered temperature sensing. This capability allows for efficient temperature monitoring without relying on external power sources, advancing remote, and autonomous sensing applications.

A flexible dual-mode triboelectric sensor for strain and tactile sensing toward human-machine interface applications

In recent years, there has been significant progress in the development of flexible sensors for human-machine interfaces. However, the triboelectric principle, especially which based on sliding mode, is relative rarely applied to flexible strain sensors. Therefore, a novel triboelectric flexible stretchable sensor has been designed with a simple structure, convenient fabrication process, and effective response to various strain signals (Within the range of 0%−200%, the average sensitivity is 49.07 mV per 1% strain). This sensor operates in a new triboelectric working mode: variable charge density mode (VCD mode). Furthermore, the sensor can also be utilized for tactile sensing in vertical contact-separation mode without any structural modifications. Based on this strain-tactile dual-mode flexible triboelectric sensor (STDFTS), its applications for human-machine interface have been explored: gesture recognition (recognition accuracy of five gestures reaches 99.4%) based on tactile sensing and mouse replacement based on dual working modes. The STDFTS proposed in this article provides a new alternative solution for human-machine interfaces, greatly expanding the application scenarios of triboelectricity. The sensor's innovative design and dual-mode functionality open up new avenues for research and development in the field of triboelectric nanogenerator, flexible sensors and human-machine interaction.

Reversal mechanism of triboelectrification in steel-polymer frictional interface for in-situ monitoring of transfer films

The triboelectric behavior of metal sliding against polymer in triboelectric nanogenerators (TENGs) is highly affected by the friction condition. However, the electrification behavior of the friction interface and its evolutionary mechanism during friction are still unclear. Herein, the internal mechanism of the triboelectric behavior of the material transfer modulation interface when the steel slides against PTFE/PE/POM polymers is systematically investigated in a tribological way. Different from the electrification in the vertical contact-separation mode, the surface potential of the three polymers will evolve inversely with time during friction. The reason for the reverse evolution is classified as the induced effect after the transfer of the material with residual charge to the steel ball. The formation of the transfer film not only stabilizes and reduces friction but also induces the inversion of the potential of the substrate surface. By polishing the transfer film on the surface of the steel ball, the inversion of the surface potential can be repeated reproducibly. Furthermore, the existence of the transfer film is monitored in situ by monitoring the surface potential change of the steel ball. This work provides a vital reference for revealing the physical mechanism of interface triboelectrification and expanding the tribological characterization methods.

Triboelectric Nanogenerators Based on Nanostructured Layers of Zinc Oxide Deposited on Carbon Fabric

In this work, to obtain textile triboelectric layers for wearable flexible triboelectric nanogenerators (TENGs), we used two modes of growing nanostructured zinc oxide (ZnO) arrays on a carbon fabric (CF) using the automatic Successive Ionic Layer Adsorption and Reaction (SILAR) method. To produce a CF/ZnO_nr triboelectric textile with an array of intergrown short ZnO nanorods, we used a pre-coating of carbon fibers with ZnO seed layers. When the ZnO layer was fabricated by automatic SILAR on bare carbon fabric, we obtained the CF/ZnO_ns textile with an array of interconnected ZnO nanosheets 50–100 nm thick. As a proof of concept, we developed and tested two prototypes of flexible vertical contact–separation mode CF/ZnO_nr/PET/ITO and CF/ZnO_ns/PET/ITO TENGs, in which a gap was involuntarily formed between the smooth PET layer and the woven carbon textile coated with nanostructured ZnO films. In pressing tests with a force of ~5 N (pressure ~33 kPa), the CF/ZnO_ns/PET/ITO TENG created a higher open-circuit voltage up to 30 V and a higher maximum surface charge density of 1.3 μC/m2. In the successive press–release tests, this TENG showed an output voltage of 3.6 V, a current density of 1.47 μA/cm2, and a power density of 1.8 µW/cm2, confirming its effectiveness.

Fabrication of high-performance triboelectric nanogenerator based on Ni3C nanosheets to self-power thermal patch for pain relief

In this work, we report a vertical contact-separation mode triboelectric nanogenerators (TENG) comprising of Ni3C/PDMS composite and Nylon Nanofibers for self-powering a nichrome wire-based thermal patch for muscular/joint relaxation. An optimised composition of Ni3C (25 wt%) and PDMS as a tribo-negative material and Nylon Nanofibers synthesised via electrospinning on copper electrode foil as a tribo-positive material were used to fabricate the TENG. The fabricated TENG exhibits outstanding output generating an average open circuit voltage of ∼252 V, an average short circuit current of ∼40.87 μA and a peak power of ∼562.35 μW cm−2 at a matching resistance of 20 MΩ by manual tapping. Enhancement in contact area due to electrospun nylon and micro capacitive Ni3C flakes in dielectric PDMS contribute to the exceptional performance of the TENG. The optimised TENG is then connected to a full bridge rectifier with a 100 nF filtering capacitor to convert the AC voltage to a DC output with a peak voltage of ∼5.4 V and a ripple voltage of ∼1.04 V to recharge an ICR 18650 Li-ion battery, which functions as a medium to improve electrical energy flow to the heat patch. The electrical energy is converted into heat energy by a wounded nichrome wire placed inside the heat patch. The nichrome wire of length 3 cm with appropriate number of windings was employed in the heat patch. An increment of 45 °F can be observed by switching the charged Li-ion battery-based circuit ON for just 30 s. The strategy of self-powering a heat patch using this TENG finds enormous applications in physiotherapy and sports to relieve muscle and joint pains.

Development of Flexible Semiconductors Based on g-C3N4/Cu2O P–N Heterojunction for Triboelectric Nanogenerator Application

This research aims to develop flexible semiconductors for triboelectric nanogenerator (TENG) applications. The sample powders of graphitic carbon nitride (g-C3N4) and copper (I) oxide (Cu2O) as N-type and P-type semiconductors, respectively, were synthesized. The semiconductors were prepared to be a composite film with alginate. The structure, morphology, and purity of the N- and P-type semiconductors were characterized using X-Ray diffraction and scanning electron microscopy techniques. Through the optical characterization, the N-type semiconductor showed the calculated energy band gap of 2.80 eV, while the P-type semiconductor was 1.90 eV. The P–N junction property of prepared samples was confirmed using a nonlinear current–voltage characteristic. After that, two flexible semiconductors were frictional paired for TENG. Through a vertical contact-separation mode, the P–N junction-based TENG produced a maximum output voltage and current of 3.90 V and 0.44 µA, respectively, with a maximum output power of 0.35 µW at 10 MΩ. In summary, the present work achieved the preparation of flexible P- and N-type semiconductors. The feasibility to harvest the mechanical energy was demonstrated in the TENG configuration. This idea is crucial for the future development of flexible harvesting/sensing devices using a novel concept.

Silk Fibroin/Amino Acid Hybrid Organic Piezoelectric-Triboelectric Nanogenerator

Triboelectric nanogenerators (TENG) with great performance and biodegradability are desired for the expansion of novel medical devices and wearable electronics. The present study aims at the preparation of natural silk in the form of silk fibroin (SF) film for utilization in TENG and further improving its output efficiency by embedding organic-piezoelectric gamma-glycine (γ-gly) amino acid to be a hybrid-organic piezoelectric/triboelectric nanogenerator (HO-P/TENG). The attenuated total reflectance infrared spectroscopy (ATR-IR) results demonstrated the N-H, C = O, and C-N bonding for SF and SF/γ-gly, confirming its dominant effect with a strong electron-donating tendency from those amino groups. The scanning electron microscope (SEM) and synchrotron radiation X-ray tomographic microscopy (SR-XTM) images show good dispersibility of incorporated γ-gly on the surface and also inside the SF matrix relating to its content to improve the electrical performance homogeneously. By fabricating the device in the vertical contact-separation mode, the present SF/γ-gly HO-P/TENG at 15 wt% provides the maximum output voltage (VOC ) and current (ISC ) of 81 V and 121 μA with a maximum output power (Pmax ) of 205 μW at the external load resistance of 5 MΩ. This SF-based HO-P/TENG has the advantage of being cost-effective with simple fabrication, demonstrating great promise for practical uses.

Multi-mode and durable fiber triboelectric nanogenerator for power and sensor enabled by Hookean vascular stent structure

Fiber-sharped triboelectric nanogenerators (F-TENGs) play an important role in distributed energy harvest resources for E-textiles and IoT. Most of the current F-TENGs work in single mode with low power densities. On the contrary, multi-mode has been verified to be an effective way to enhance the energy output of F-TENGs. However, the working mechanisms of multi-mode F-TENGs are not clear yet. In this work, a novel vascular stent-like F-TENG is proposed and two working modes are demonstrated, which can be realized single-electrode mode and contact separation mode accumulation in one motion and lead to a higher electric output. The voltage of the dual-mode reaches 9 V cm−1 under 1 Hz, which is 3 times the value of single-electrode mode, and 2 times the value of vertical contact-separation mode. In addition, the F-TENG shows excellent durable stability after 10,000 cycles. Furthermore, the F-TENG has been successfully applied as an intelligent shoe pad for human walking monitoring. This vascular stent-like F-TENG, owning to its high energy generation performance and easy mass-scale fabrication, is promising and able to extend the application of textile-based electronics.

Electron Transfer in Contact Electrification under Different Atmospheres Packaged inside TENG.

Contact electrification (CE), a common physical phenomenon, is worth discussing. However, there are few reports on the influence of atmosphere on CE, or on the performance of triboelectric nanogenerators (TENG), based on CE by encapsulating gas inside. Here, we propose physical processes of electron transfer to interpret the impact of the gaseous atmosphere on CE. An atmosphere-filled triboelectric nanogenerator (AF-TENG) encapsulated five different gas-components of air based on the vertical contact separation mode was prepared. The sensitivity (1.02 V·N-1) and the power density (9.63 μW·m-2) of the oxygen-atmosphere-filled AF-TENG were 229.03% and 157.81% higher than these (0.31 V·N-1 and 3.84 μW·m-2) of the nitrogen-atmosphere-filled AF-TENG. As the oxygen atom possesses more atomic energy levels than other atoms, this could act as a "bridge" for more electrons to directly transfer between the two materials. The device package under different atmospheres could not only strengthen understanding of CE and improve the performance of TENG, but also be potentially applicable to prevent and control unnecessary damage caused by static electricity.

Engineering of electrodes with 2D Ti3C2Tx-MXene sheets and chloride salt for robust and flexible high electrical power triboelectric nanogenerator

This article focuses on the development of triboelectric nanogenerator (TENG) by utilizing advanced 2D nanomaterials with innovative design and easy fabrication method to achieve durable TENG with high-power density and improved cycling performance. Herein, we fabricated a layer-by-layer stacked vertical contact-separation (CS) mode TENG. In this unique design, we incorporated a thin film of micron-sized Ti3C2Tx-MXene ultrathin sheets (TMSs) into a polyethylene terephthalate (PET) based tribo-negative electrode. A tribo-positive layer was prepared by integrating an optimized amount of NaCl into a polyvinyl alcohol (PVA) matrix. After optimization of both triboelectric layers, the optimized TMS-TENG showed an open-circuit voltage (Voc) ∼ 390 V, short-circuit current (Isc) ∼ 96 μA, and power density of 6.66 W·m−2. The boosted performance is due to the synergistic effect of TMSs, used as a charge trapping layer on the electronegative side, and the impact of an NaCl:PVA impregnated layer on the electropositive side of the TENG. The ultrathin-layered structures of sandwiched TMS film serve bifunctionally as a charge accumulation and charge trapping entity simultaneously, increasing the charge separation due to high dielectric constant, and thus increasing the overall output power of the fabricated TENG. The prepared TMS-TENG was tested as a pressure sensor to monitor different sensitive physiological movements of the human body. Further applications of the designed TMS-TENGs have been revealed by powering more than 500 LEDs, an electronic calulator, and swiftly charging micro-capacitors by utilizing direct output power. By engineering electrodes, we can gain insight into the specific role that TMSs play in enhancing the performance of TENGs. This research provides a new avenue for designing self-powered pressure/motion sensors in robotics and harvesting biomechanical energy as electrical energy for sustainable electronics.

Exploring the effects of substrate and substrate temperature on the properties of radio frequency magnetron sputtered ZnO thin films

The physical and optical properties of zinc oxide thin films strongly depend on the film deposition techniques. In this work, RF magnetron sputtering was used to deposit ZnO thin films on various substrates (glass, quartz, ITO-coated glass, FTO-coated glass, Si(100), Si(100)/ SiO2) to study the role of substrate and substrate temperature on the morphological, structural and optical properties of the film grown. A detailed discussion on various aspects like surface morphology, strain, photoluminescence, bandgap, surface roughness, and material composition has been done. Compressive stress was present in the films created at room temperature and differed for various substrates based on the lattice mismatch. The nature and temperature of the substrate are found to affect the surface topography of films. Substrate and substrate temperature influenced the emission characteristics of ZnO thin films. In oxygen-rich substrates, defect emissions differed. We found that quartz is a better substrate to fabricate ZnO at room temperature and both Si and Si/SiO2 are preferable at high temperatures due to the lower lattice mismatch and thermal expansion coefficient. Comparing the electrical characteristics of ZnO thin films grown on glass and quartz substrates, ZnO on glass exhibited lower resistivity and higher carrier concentration. The Triboelectric nanogenerator (TENG) combining ZnO and PDMS, was developed to operate in vertical contact-separation mode. The obtained open circuit voltage was 30 V and 33 V for ZnO grown over ITO and FTO respectively, and the slight increase is due to the rougher film's surface on FTO than ITO. The selection of substrate is crucial in many applications and our findings provide an overview of the suitability of substrate and substrate temperature for the fabrication of ZnO thin film-based optoelectronic devices.

Universal Energy Solution for Triboelectric Sensors Toward the 5G Era and Internet of Things.

The launching of 5G technology provides excellent opportunity for the prosperous development of Internet of Things (IoT) devices and intelligent wireless sensor nodes. However, deploying of tremendous wireless sensor nodes network presents a great challenge to sustainable power supply and self-powered active sensing. Triboelectric nanogenerator (TENG) has shown great capability for powering wireless sensors and work as self-powered sensors since its discovery in 2012. Nevertheless, its inherent property of large internal impedance and pulsed "high-voltage and low-current" output characteristic seriously limit its direct application as stable power supply. Herein, a generic triboelectric sensor module (TSM) is developed toward managing the high output of TENG into signals that can be directly utilized by commercial electronics. Finally, an IoT-based smart switching system is realized by integrating the TSM with a typical vertical contact-separation mode TENG and microcontroller, which is able to monitor the real-time appliance status and location information. Such design of a universal energy solution for triboelectric sensors is applicable for managing and normalizing the wide output range generated from various working modes of TENGs and suitable for facile integration with IoT platform, representing a significant step toward scaling up TENG applications in future smart sensing.

On the contact electrification mechanism in semiconductor–semiconductor case by vertical contact-separation triboelectric nanogenerator

With the speed of industrialization accelerating, the traditional energy is in the predicament of being exhausted. Humans urgently need a clean energy to maintain the peace and development. Triboelectric nanogenerator (TENG) is a tiny device that collects and converts the renewable energy, such as wind, vibration and tidal/blue energy, into electrical energy. As the most significant working principle of TENG, contact electrification (CE) has been broadly studied since it was documented thousands of years ago. A large number of related researches are reported. However, most of them are focused on the polymer materials, device structures and potential applications. There are few literatures about the mechanism of CE, especially in the semiconductor–semiconductor case. Semiconductor–semiconductor CE is a promising method to generate electricity, which has been used in many fields, such as the photodetector and displacement sensor. Therefore, it is necessary to establish a serious and detailed theory in order to deeply explain the underlying mechanisms of semiconductor–semiconductor CE. In this work, a novel Fermi level model based on energy band theory is proposed to illustrate the semiconductor–semiconductor CE mechanism. By assembling a ZnO/Si vertical contact-separation (CS) mode TENG, the charge transfer introduced by CE is systematically measured. According to the energy band theory and TENG governing equation, the experimental data is qualitatively and quantitatively analyzed. Moreover, the effects of different concentrations of growth solutions on the morphology of ZnO nanowires and the Fermi level difference between ZnO and Si are explored as well. Results show that it is the Fermi level difference that dominates the short circuit transfer charge amount and direction of semiconductor–semiconductor CE mechanism. Our work can be applied to understand the CE mechanism in semiconductor–semiconductor case and broaden the application prospects of semiconductor-based TENG.

A PA66 lamellar crystal film with excellent triboelectric performance in vertical contact separation mode

Triboelectric nanogenerators (TENGs) are gaining tremendous attention as an environmentally friendly technology that converts low-frequency mechanical energy into electrical energy.

Triboelectric nanogenerator module for circuit design and simulation

Triboelectric nanogenerator (TENG) technology is an emerging nanotechnology with potential applications in energy-harvesting electronics, self-powered electronics, high-voltage electronics, and other smart electronics. Electronic circuits, such as power management circuits and driving circuits, play key roles in the applications of TENGs; thus, because simulation is the most efficient and cost-effective way to design a circuit, the need to design TENG-related electric circuits through circuit simulation rather than through experiments is urgent. However, as power sources with unique output performances, TENGs do not exist in the device libraries of commonly used circuit simulation software, which prevents circuit designers without TENG expertise from designing TENG-related circuits and hinders the widespread development of TENG technology. In this work, we construct a TENG module based on the vertical contact-separation mode in commercial MATLAB software. The simulated outputs of the constructed TENG module, including voltage, current, power, and load-dependent characteristics, are in good agreement with theoretical results. Furthermore, we utilize this TENG-like power source to study the charging efficiency of a capacitor in a resistor-capacitor series circuit and demonstrate the interconnection with other application modules. The results of this work will allow load circuits for TENGs to be more easily designed by using computer-aided circuit simulations, which is of great significance to the development of TENG technology.

Physically doped and printed elastomer films as flexible high-performance triboelectric nanogenerator for self-powered mechanoelectric sensor for recovering voice and monitoring heart rate

Flexible triboelectric nanogenerator (f-TENG) is usually fabricated from elastomer. However, elastomer is generally not as effective as fluorine or amine plastics in gaining or donating electrons, which compromises the electrical performance of the fabricated f-TENG. Herein, this study demonstrates a simple solution-casting based physical doping strategy to develop high-performance triboelectric elastomer films and f-TENGs. Styrenic elastomer film was physically doped using various fluorines or amines. The doped elastomer films were further printed with flexible silver electrodes and then were used to construct a wide spectrum of f-TENGs. Remarkably, at vertical contact-separation mode, the f-TENG fabricated from the trifluoroacetic acid and polystyrene-bound triazabicyclodecene respectively doped films generated up to 385 V voltage with maximum 39.7 μA/cm2 current density and 15.1 mW/cm2 power density. This f-TENG also effectively converted a wide range of low-frequency body motions (run, walk, finger bending, throat vibration, and heart electrical impulse) to electricity. This f-TENG enables to develop self-powered real-time mechanoelectric sensor for recovering voice and monitoring heart rate. The results also indicated that trifluoroacetic acid was generally more effective than other fluorines in enhancing the electron-accepting ability of styrenic elastomer film and polystyrene-bound triazabicyclodecene was more effective than other amines in enhancing the electron-donating ability of styrenic elastomer film.

Eco-Friendly Keratin-Based Additives in the Polymer Matrix to Enhance the Output of Triboelectric Nanogenerators.

A triboelectric nanogenerator (TENG) is an energy generator that converts mechanical energy into electrical energy using triboelectricity at a nanoscale. Given their potential application as power sources in electronic devices, various attempts have been made to improve their output performance. Here, we present an eco-friendly, low-cost, and facile fabrication method to enhance TENG characteristics with keratin protein additives. Keratin sources, human and cat hair, are processed into powder and added to the friction layer, which increases their positive charge affinity, thereby boosting the output performance of the TENG. The output performances of the keratin-added TENG (K-TENG) are measured in the vertical contact-separation mode, with both additives having the highest output values at 5 wt % load. The K-TENG generates more output voltage and current values than the pristine TENG by 90 and 208%, respectively. Hence, we conclude that this method would potentially promote TENG as a strong candidate for a competitive "green" energy harvesting device in future electronics applications.