Triboelectric Nanogenerators: Design, Fabrication, Energy Harvesting, and Portable-Wearable Applications

Scavenging energy from our day-to-day activity into useful electrical energy be the best solution to solve the energy crisis. This concept entirely reduces the usage of batteries, which have a complex issue in recycling and disposal. For electrical harvesting energy from vibration energy, there are few energy harvesters available, but the fabrication, implementation, and maintenances are quite complicated. Triboelectric nanogenerators (TENG) having the advantage of accessible design, less fabrication cost, and high energy efficiency can replace the battery in low-power electronic devices. TENGs can operate in various working modes such as contact-separation mode, sliding mode, single-electrode mode, and free-standing mode. The design of TENGs with the respective operating modes employed in generating electric power as well as can be utilized as a portable and wearable power source. The fabrication of triboelectric layers with micro-roughness could enhance the triboelectric charge generation. The objective of this chapter is to deal with the design of triboelectric layers, creating micro structured roughness using the soft-lithographic technique, fabrication of TENGs using different working modes, energy harvesting performance analysis, powering up commercial devices (LEDs, displays, and capacitors), and portable-wearable applications

Impact of HIV Infection on Radiographic Features in Patients with Pulmonary Tuberculosis

Background. There is insufficient data on the radiographic presentation of tuberculosis in human immunodeficiency virus (HIV) infected patients from India. Methods. We examined the chest radiographs of 181 patients including 82 HIV positives with newly diagnosed sputum culture positive pulmonary tuberculosis before and after the completion of anti-tuberculosis treatment (ATT). Patients with smear/culture positive pulmonary tuberculosis were treated with Revised National Tuberculosis Control Programme (RNTCP) Cat-I regimen (2EHRZ3/4HR3). An independent assessor blinded to HIV and clinical status of patients read the radiographs. Results. At presentation, HIV seropositive patients were significantly more likely to have normal chest radiographs (14.2% vs 0), miliary tuberculosis (10.7% vs 1%) and pleural effusion (16.6% vs 3%), and less likely to have cavitation (17.8% vs 39.4%) as compared to HIV negative patients. At the end of treatment, HIV positive patients were more likely to have normal radiographs (42.8% vs 1.2%), and less likely to have fibrosis (17.8% vs 42.5%). Conclusions. The radiographic presentation of pulmonary tuberculosis in HIV-infected patients is atypical with less cavitation, and more dissemination. On completion of ATT, patients with HIV have less radiographic sequelae in the form of fibrosis. These features may be due to the reduced inflammatory response that patients with HIV infection may be able to mount

A Study on Fiber Optic Temperature Sensor Using Al₂O₃ as High Index Overlay for Solar Cell Applications

Recently, the performance of solar cell is impacted by rising panel temperatures. For solar cells to work at their best and have the longest possible useful life, the temperature of the panels must be kept at an ideal level. Current temperature sensors have a slow response time, poor accuracy, and low resolution. Meanwhile, Al2O3 and its derivatives have demonstrated a noteworthy role in temperature sensing applications due to its greater surface area, ease of synthesis, tailored optical characteristics, high melting point, and high thermal expansion coefficient. Al2O3-based nanoparticles have been employed in fiber optic-based temperature sensors as a sensing layer, a sensitivity improvement material, and a sensing matrix material. In this chapter, we discuss the function of Al2O3-based nanomaterials in evanescent wave-based temperature sensors, sensing characteristics such as sensitivity, linearity, and repeatability. The ZAZ-based sensor (Section 3.1) shows an operating temperature range between 100.9°C and 1111.0°C, the temperature sensitivity becomes 1.8 × 10−5/°C. The fabricated sensor had a linearity of 99.79%. The synthesized Al2O3 nanoparticles (Section 3.2) were given better linearity and high sensitivity (~27) at 697 nm compared with other sensing materials such as ZnO, SnO2, TiO2. The Al2O3-MgO (50–50%) (Section 3.3) demonstrated an ultrahigh sensitivity of 0.62%/°C with a better linear regression coefficient of 95%. The present advances and problems are also discussed in detail

Exalted Electric Output via Piezoelectric–Triboelectric Coupling/Sustainable Butterfly Wing Structure Type Multiunit Hybrid Nanogenerator

The scalable synthesis of an irregular composite surface impregnated with high-performance piezoelectric 0.3Ba_0.7Ca_0.3TiO₃–0.7BaSn_0.12Ti_0.88O₃ nanoparticles (0.3BCT–0.7BST NPs) for enhancing the power density of hybrid nanogenerators (H-NGs) using a contact–separation structure is reported for the first time. The designed high-performance butterfly wing structure type multiunit system, consisting of four simple arc-shaped H-NGs, has dual functionality as a stand-alone power source for light-emitting diodes and charging Li coin cells and as a self-powered air pressure sensor. Manyfold increments of the open-circuit voltage (<i>V</i>_OC(p–p) = 572 V) and short-circuit current (<i>I</i>_SC(p–p) = 1.752 mA) were observed for H-NG with an irregular surface compared with a piezoelectric nanogenerator (P-NG) (<i>V</i>_OC(p–p) = 53 V, <i>I</i>_SC(p–p) = 2.366 μA). Compared with the power density of a flat surface based H-NG (333 W/m²), the power density of a single arc-shaped H-NG with an irregular surface was 4-fold higher at 1336 W/m², and that with a micropillar surface was twice as high (632 W/m²). A high functional property of fillers along with polydimethylsiloxane matrix improves the surface charge density of the composite film. The surface charge density of the H-NG was greatly influenced by the distance between the active layers, micropores, thickness, relative permittivity, and applied force

Contact-electrification enabled water-resistant triboelectric nanogenerators as demonstrator educational appliances

Triboelectric nanogenerators (TENG) work on the principle of tribo and contact electrification, which is a common phenomenon observed in daily life. TENGs are moving closer to commercialization, particularly for small scale energy harvesting and self-powered sensing. The toys and games industry has attracted a large audience recently with the introduction of digital toys. In this paper we embedded TENGs to power up a toy and operate during its specific application. We have modified two potential electronic demonstrator applications using TENG for lobster toy (LT-TENG) and stress ball (SB-TENG) device. The LT-TENG device generates a maximum electrical response of 60 V/2 µ A, with a power of 55 µ W and power density of 0.065 µ W m ^−2 at a load resistance value of 10 MΩ. Similarly, the SB-TENG device made of aluminum and PDMS as the triboelectric layers generates a maximum electrical output response of 800 V and 4 µ A peak to peak current with an instantaneous power of 6 mW and a power density of 3.5 mW m ^−2 respectively at a load resistance of 10 MΩ. In addition, the layers of the TENGs are packed with polyethylene to maintain the performance of the nanogenerator under harsh environmental conditions, especially with humid environments. The water resistance studies proved that the packed SB-TENG is impervious to water. The LT-TENG device is accompanied by four LEDs, and the device lights up upon actuating the handle. The SB is connected with the measuring instrument to record the quantity of force at which the SB is pressed. The adopted approach paves the way to convert these traditional toys into battery-free electronic designs and its commercialization

Achiral bis-imine in combination with CoCl2: A remarkable effect on enantioselectivity of lipase-mediated acetylation of racemic secondary alcohol

A bis-imine (prepared via a new FeCl3-based method) in combination with CoCl2 facilitated lipase-mediated acetylation of the (R)-isomer of a racemic benzylic secondary alcohol with 91% ees. The methodology was used for the preparation of the known drug rivastigmine

Smart maracas: an innovative triboelectric nanogenerator for earthquake detection and energy harvesting

In an era marked by a growing demand for sustainable energy solutions and resilient disaster management systems, the convergence of innovative technologies holds the promise of addressing multifaceted challenges. This manuscript explores the multifunctional capabilities of the "smart maracas", a novel triboelectric nanogenerator (TENG) designed to harvest mechanical energy and simultaneously serve as an earthquake sensor. The smart maracas is a striking example of the potential of TENGs to harness mechanical motion for practical applications. The device converts mechanical energy into electrical power through meticulous engineering, opening avenues for self-sustaining power sources in various domains. The manuscript outlines the device's structural design, working principle, and real-time applications, spanning bio-mechanical energy harvesting, vibrational energy scavenging, rotational energy harvesting, and a unique sensing application for door monitoring. A pivotal aspect of this research revolves around the smart maracas' role as an earthquake sensor. Rigorous experiments were conducted to assess the device's responsiveness to simulated seismic forces. Notably, a linear relationship with an R² value of 0.9989 was established between the voltage generated by the smart maracas and seismic acceleration. This remarkable correlation underscores the device's precision and reliability in detecting seismic events, opening doors for cost-effective earthquake monitoring solutions

Battery-Free Electronic Smart Toys: A Step toward the Commercialization of Sustainable Triboelectric Nanogenerators

Next-generation toys are designed to entertain and interact with children. Such toys need a power source, generally a battery that must be replaced frequently, leading to increased maintenance costs. Recently, an innovative biomechanical energy harvester called a triboelectric nanogenerator (TENG) was introduced as an eco-friendly generator that scavenges waste energy. Here, in a step toward the commercialization of TENG devices, we present a novel approach that uses TENG technology to develop battery-free electronic smart toys. This robust, eco-friendly, and cost-effective approach for harnessing biomechanical energy can transform a traditional toy into a smart toy. With this innovative idea, we developed a smart clapping toy (SCT-TENG) and a smart duck toy (SDT-TENG) using biocompatible materials. We employed a simple inbuilt circuit with light-emitting diodes that are powered using biomechanical energy. The SCT-TENG and SDT-TENG exhibited output voltages of 65 V_p‑p and 260 V_p‑p, respectively. We believe that the use of TENG technology for battery-free electronic smart toys opens up new possibilities for the commercialization of TENGs and the field of battery-free smart toys

Direct In Situ Hybridized Interfacial Quantification to Stimulate Highly Flexile Self-Powered Photodetector

In contrary to the existing externally powered photodetectors, a reliable approach for self-powered photodetection is designed for the first time through an internally integrated concept via coupling of piezotronic with photonic effects. A flexile self-powered photodetector (F-SPPD) developed by one-dimensionally grown floral-like F-ZnO nanorods on a poly­(vinylidene difluoride) substrate conjointly performs the tunability of optical properties through the exploitation of strain-induced piezoelectric potentials (σ⁺, σ^–) at the electrode interfaces. The experimental observation showed an ideal photodetector characteristics with a 1-fold increment in photoresponsivity (<i>R</i>_365nm ∼ 22.76 mA/W) by lowered Schottky barrier heights (Φ_SB1^T, Φ_SB2^T) through externally governed tensile strain (+ε). Further, the self-powered operation mode of F-SPPD exhibited higher spectral sensitivity (5.69 mA/(W cm^–2)) than that of the photodetector (3.47 mA/(W cm^–2)) operated under unstrained condition. This work effectively brings in the direct integration ideology of two different systems into a single module toward the downscaling of device size and weight

Human Interactive Triboelectric Nanogenerator as a Self-Powered Smart Seat

A lightweight, flexible, cost-effective, and robust, single-electrode-based Smart Seat–Triboelectric Nanogenerator (SS-TENG) is introduced as a promising eco-friendly approach for harvesting energy from the living environment, for use in integrated self-powered systems. An effective method for harvesting biomechanical energy from human motion such as walking, running, and sitting, utilizing widely adaptable everyday contact materials (newspaper, denim, polyethylene covers, and bus cards) is demonstrated. The working mechanism of the SS-TENG is based on the generation and transfer of triboelectric charge carriers between the active layer and user-friendly contact materials. The performance of SS-TENG (52 V and 5.2 μA for a multiunit SS-TENG) is systematically studied and demonstrated in a range of applications including a self-powered passenger seat number indicator and a STOP-indicator using LEDs, using a simple logical circuit. Harvested energy is used as a direct power source to drive 60 blue and green commercially available LEDs and a monochrome LCD. This feasibility study confirms that triboelectric nanogenerators are a suitable technology for energy harvesting from human motion during transportation, which could be used to operate a variety of wireless devices, GPS systems, electronic devices, and other sensors during travel