Nanogenerators as a fundamental of a sustainable and intelligent energy future

Zhong Lin Wang

Prof. Zhong Lin Wang is a preeminent physicist and materials scientist whose groundbreaking work has revolutionized the fields of nanotechnology, energy harvesting, and self-powered systems. He currently serves as the Director of the Beijing Institute of Nanoenergy and Nanosystems and holds the distinguished titles of Regents' Professor and Hightower Chair (Emeritus) at the Georgia Institute of Technology. Wang is widely recognized as the pioneer of the nanogenerators field, which has enabled advancements in distributed energy, self-powered sensors, and large-scale blue energy. Additionally, he coined and developed the fields of piezotronics and piezo-phototronics, which have significant implications for third-generation semiconductors. Throughout his illustrious career, Wang has received numerous prestigious awards, including the Global Energy Prize (2023), the Albert Einstein World Award of Science (2019), the ENI Award in Energy Frontiers (2018), the James C. McGroddy Prize in New Materials from the American Physical Society (2014), and the MRS Medal from the Materials Research Society (2011). His groundbreaking work has earned him memberships and fellowships in some of the world's most esteemed scientific academies, including the US National Academy of Inventors, the Chinese Academy of Sciences (as a foreign member), the European Academy of Sciences, the European Academy of Engineering, the Korea Academy of Science and Technology (as a foreign member), the Academia Sinica, and the Canadian Academy of Engineering (as an International Fellow).

Pooi See Lee

Prof. Pooi See Lee is the President's Chair Professor in materials science and engineering at Nanyang Technological University, Singapore. She received her PhD from the National University of Singapore in 2002 in the field of semiconductor materials. Her current research focuses on soft electronics, mechanical energy harvesters, human–machine interfaces, sensors and actuators, wearable technology, and hybrid materials for soft robotics. Lee can be reached by email at E-mail: pslee@ntu.edu.sg.

Ya Yang

Prof. Ya Yang is currently a professor at the Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, China. He received his PhD in materials science and engineering from the University of Science and Technology Beijing, China. His main research interests focus on ferroelectric materials and devices for energy conversion, self-powered sensing, and some new physical effects. He has published one book and more than 200 SCI academic papers. These papers have been cited more than 27 000 times, and the corresponding H-index is 98. He is the Editor-in-Chief of Nanoenergy Advances and the editorial committee member of InfoMat, Nano-Micro Letters, Nanoscale, iScience, Nanoscale Advances, and other journals. He is the Guest Editor of Research, iScience, Nanomaterials, and Energies. Yang can be reached by email at E-mail: yayang@binn.cas.cn.

As the Internet of Things (IoT) era advances, the proliferation of electronic devices and expansive sensing networks continues at an unprecedented pace. However, this rapid growth relies heavily on small, disposable batteries, contributing to significant environmental concerns as billions of devices and their associated batteries accumulate. Nanogenerators (NGs), devices capable of harvesting ambient energy in various forms, have emerged as a promising solution to this challenge. Over the past decade, extensive research has focused on optimizing their structural design and advancing material engineering strategies to enhance energy conversion efficiency and overall performance. Simultaneously, the application landscape of NGs has broadened, encompassing biomedical devices, wearable electronics, and industrial systems, highlighting their potential as sustainable and eco-friendly power sources. This themed collection explores strategies for improving device performance and durability while emphasizing practical applications, underscoring the role of NGs as a fundamental technology in shaping a sustainable energy future.

Triboelectric nanogenerators (TENGs), first introduced in 2012, have rapidly emerged as a transformative platform for distributed energy harvesting and sensing. Their performance is intimately tied to materials properties, including surface charge density, microstructure, permittivity, and overall robustness. Recent advances in triboelectric materials have driven substantial gains in output and environmental sustainability. Hao and colleagues, for example, engineered biodegradable polyethylene oxide (PEO)/cysteine nanofiber films (PCFs), achieving a power density of 6.6 W m⁻²—far exceeding other eco-friendly tribo-materials. A multilayer funnel-shaped TENG (MF-TENG) built from these films efficiently captures low-level mechanical energy and powers self-sustained IoT nodes, emphasizing a scalable pathway for high-output, biodegradable devices (https://doi.org/10.1039/D4TA06845A). Thermal stability remains another critical performance bottleneck, as plasticized PVC devices degrade under elevated temperatures due to plasticizer leakage. Addressing this, Park et al. embedded TiO₂ nanoparticles into PVC dielectric gels, boosting permittivity and suppressing leakage, thereby achieving robust performance of 121 V, 11.1 μA, and 149 μW cm⁻² up to 55 °C. This design doubles as a temperature-tolerant pressure sensor, positioning TENGs for use in variable environments (https://doi.org/10.1039/D4TA07867E). Beyond materials engineering, advancing performance also requires refined theoretical frameworks. Chen et al. introduced the space tribo-charge region (STCR) model, which treats triboelectric charge as a finite-thickness distribution rather than a two-dimensional surface layer. Validated in PDMS/FEP devices, this model clarifies field distributions, polarity-swapping phenomena, and voltage behavior, providing a realistic basis for next-generation device optimization (https://doi.org/10.1039/D5TA01136A).

Building on performance optimization, the field is now increasingly converging on multifunctionality and device longevity. Podder and co-workers demonstrated a hybrid pyro-phototronic nanogenerator (HPyNG) that leverages ZnO's lattice-driven pyroelectricity and crystalline rubrene's surface polarization to synergistically boost photovoltage generation. With ultra-low light detection down to 50 nW, this design exemplifies how inorganic–organic integration enables multi-stimuli-responsive nanogenerators (https://doi.org/10.1039/D5TA00063G). Complementary efforts in pyroelectric materials have similarly pushed energy harvesting frontiers. Narayan et al. proposed new figures of merit (FoMs) that incorporate thermal conductivity and diffusivity, enabling informed material selection for dynamic temperature fluctuations. Their comparative analysis across ceramics, polymers, thin films, composites, and 2D systems provides a roadmap for designing pyroelectrics optimized for high-frequency cycles (https://doi.org/10.1039/D5TA00704F).

Lead-free piezoelectric nanogenerators also highlight durability-oriented innovation. A Cs₃Sb₂I₉/PVDF composite achieved an 82% electroactive phase and a piezoelectric coefficient of 7.48 pm V⁻¹, delivering 85 V and 1.26 μW cm⁻² while maintaining >10 000-cycle stability. A 63% piezo-phototronic enhancement further expands its utility in optoelectronics and wearable IoT systems (https://doi.org/10.1039/D4TA08601E). Similarly, PAN/MWCNT composite fiber bilayers achieved threefold current enhancement via impedance reduction, supported by KPFM and COMSOL modeling. This architecture enables reliable gesture recognition and wearable energy harvesting (https://doi.org/10.1039/D4TA07120D). MOF-engineered cellulose-based TENGs demonstrated exceptional durability, achieving ∼100 V output with stable adhesion and flexible integration (https://doi.org/10.1039/D4NR03909B). Novel interfacial designs further amplify output and reliability. A water-interlayer-enabled Au–Si junction improved vibration energy harvesting by ∼3 orders of magnitude through electric double-layer and built-in field effects (https://doi.org/10.1039/D5TA00099H). Similarly, loop-structured dielectric film-capacitor DC-TENGs (LFD-TENGs) demonstrated long-duration, high-peak discharges that continuously powered thousands of LEDs, illustrating scalability and practical potential (https://doi.org/10.1039/D4TA09187F).

These advances collectively position nanogenerators as multifunctional building blocks for intelligent sensing and healthcare systems. Ge et al. developed an oil–solid triboelectric sensor (OA-TENG) achieving ∼0.62 V/TAN sensitivity—triple that of PTFE devices—for real-time lubrication analysis (https://doi.org/10.1039/D5TA00241A). In parallel, Li et al. combined breathable hydrogels with deep learning algorithms, achieving 100% facial expression recognition accuracy for mental health monitoring (https://doi.org/10.1039/D5TA00253B). Next-generation adaptive systems are also emerging. Chong et al. integrated magnetorheological fluids to create sensors with tunable sensitivity up to 46.47 kPa⁻¹ and wide detection ranges (https://doi.org/10.1039/D4TA07129H), while Parashar et al. developed a machine learning-driven gait monitoring system with 99.96% accuracy for rehabilitation assessment (https://doi.org/10.1039/D4TA07496C). Complementary work in sweat ion analysis (https://doi.org/10.1039/D4TA09239B) and biodegradable organogels (https://doi.org/10.1039/D5NR00403A) further highlights TENGs' versatility, linking advanced materials engineering, AI, and healthcare innovation to create robust point-of-care and diagnostic solutions.

The rapid evolution of nanogenerators signals a paradigm shift in distributed energy and sensing technologies. Material innovation, from biodegradable composites to hybrid perovskites and MOF-based architectures, is enabling devices that combine high output, robustness, and environmental sustainability. Concurrently, refined modeling frameworks, such as the STCR model, are bringing greater predictive power to device design, while multifunctional nanogenerators are breaking boundaries in light detection, wearable sensing, and medical diagnostics.

Future research will focus on seamless integration of nanogenerators into large-scale systems, energy networks, and AI-driven platforms, establishing them as central pillars of next-generation infrastructure. By bridging breakthroughs in materials science, interfacial engineering, and machine learning, nanogenerators are poised to power an intelligent, sustainable, and interconnected future.

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