Energy harvesting properties of flexible piezoelectrets under wind-induced vibration

This paper presents a portion of recent research outcomes from the LoLiPoP-IoT Chips JU project, which focuses on developing sustainable, long-life IoT platforms by integrating advanced energy harvesting, intelligent energy management strategies, and low-power HW/SW co-design techniques to optimize battery longevity with the intention of reducing the economic and ecological impacts of frequent battery replacements. The main objective of this research is to investigate how integrated energy harvesting, adaptive power management, and efficient data-processing techniques can significantly extend battery lifetime while maintaining performance and usability in real IoT deployments. Unlike many existing studies that address isolated aspects of low-power IoT design, this work provides a comprehensive and practical approach that combines energy harvesting dimensioning, including simulation of the deployment environment, real HW power profiling, adaptive energy planning algorithms, predictive maintenance modeling, and their deployment on resource-constrained devices. The holistic integration of available technologies with newly designed approaches, such as dynamic energy scheduling, enables improvements in the overall IoT experience and a more sustainable usage. Experimental results demonstrate several outcomes. The proposed dynamic energy planning framework, particularly the “Slope” algorithm, can extend battery lifetime by up to five times compared to baseline operation. If full energy autonomy is required, the photovoltaic panel area can be reduced by approximately 77 %. Our developed simulation toolkit enables accurate estimation of energy consumption and optimal sizing of photovoltaic harvesters, while predictive maintenance models based on statistical model checking enable forecasting fault probabilities of factory equipment based on collected data. Furthermore, we conducted experiments to confirm that optimized machine-learning models can achieve high accuracy with reduced memory footprint and inference time on embedded IoT platforms.

PMMA assisted filler dispersion and morphology control in multifunctional PVDF based blend nanocomposites for absorption dominant EMI shielding and energy harvesting

Unmanned aerial vehicles for communication recovery in post-disaster scenarios: A PRISMA-based systematic review

The development of smart materials that can react to external stimuli and provide controlled and frequently reversible responses is facilitated by the coupling of physical effects. In this work, a photo-pyroelectric effect based on a piezoelectric polyvinylidene fluoride-trifluoroethylene (P(VDF-TrFE)) polymer composite with fullerene C 60 incorporated at different concentrations (1, 3, 5, 10 and 20% wt.) has been developed with the aim of obtaining a multi responsive material: together with the piezoelectric and pyroelectric characteristics of the polymer, the inclusion of the fillers allow a photo-pyroelectric response, suitable for optoelectronic applications. The addition of fullerene – C 60 leads to a mechanical plasticizing effect in the polymer matrix, revealed by the decrease of the Young’s Modulus from 335 MPa to 157 MPa and an increase in the dielectric constant from approximately 10 to 20 at 100 Hz, for P(VDF-TrFE) samples with 20% wt. of fullerene – C 60 . A pyroelectric coefficient of 20 μC/m 2 ·K was achieved with a 10% wt. fullerene – C 60 loading, while maintaining a piezoelectric response of 15 pC/N. Further, under laser irradiation and due to the photo-pyroelectric response, the composite with 10% wt. fullerene – C 60 content reaches a generated voltage of 400 mV across a temperature variation of 1.4 °C, proving the multifunctionality of the materials and their applicability in applications including infrared detectors, thermometers, or energy harvesting, among others. A new photo-pyroelectric effect in a piezoelectric composite composed of Fullerene-C60 and the ferroelectric polymer P (VDF-TrFE) is presented. The material allows to directly produce an electric signal from light absorption through to this phenomenon, which offers a novel mechanism for optoelectronic energy conversion. Further, the material maintains its piezoelectric response, allowing for multifunctional mechano-electric, pyro-electric and photo-pyroelectric response. The photo-pyroelectric effect is enabled and improved by the polymer and fullerene's synergistic interaction, which is a crucial step in the development of high sensitive flexible photonic devices. • Photo-pyroelectric effect was demonstrated in piezoelectric and pyroelectric polymer composites of P(VDF-TrFE) with fullerene. • The influence of fullerene content on P(VDF-TrFE) was evaluated. • The mechanical, dielectric and piezoelectric properties are affected by the fullerene content. • A maximum pyroelectric coefficient of 20 μC/m 2 ·K was achieved with a 10% wt. fullerene – C60. • These composites are suitable for advanced applications with a generated voltage of 400 mV across a temperature variation of 1.4 °C.

Dirac cones and topological torsional modes in phononic nanowires using Su-Schrieffer-Heeger Model.

A seahorse-exoskeleton-inspired electromagnetic energy harvester with linear-to-rotation mechanism for low-frequency human motion energy harvesting

Sodium alginate-based biomimetic crack-network Janus foam evaporator toward robust solar desalination, wastewater purification, and thermoelectric power generation.

AI-augmented residential PV system with battery storage for enhanced energy harvesting

A geometric optimization framework for a bio-inspired flexible hydrofoil energy harvester

Recent biomedical and wearable tech advances enable real-time health monitoring, but their adoption is limited by dependence on short life span, bulky batteries that require frequent replacement. This persistent limitation not only hinders device miniaturization and long-term functionality but also poses significant patient burdens, especially for implantable devices requiring invasive replacement surgery. Vibration energy harvesting offers a promising alternative by converting biomechanical energy from body movements into sustainable electrical power. This review comprehensively examines the scope, mechanisms, recent advances and challenges in vibration energy harvesters (VEHs) for biomedical and wearable applications. The four primary transduction mechanisms: piezoelectric, electrostatic, electromagnetic, and triboelectric were analyzed with a focus on their operational principles, material configurations, and biocompatibility considerations, followed by a comparative assessment of their performance, miniaturization potential, and integration challenges. The paper highlights cutting-edge developments from the past five years, including hybrid systems that synergize multiple mechanisms to enhance efficiency and adaptability for low-frequency human motion. The significance of this field lies in its potential to enable a new generation of truly autonomous, self-sustaining medical devices, thereby revolutionizing patient care by eliminating power supply as a constraint. Despite significant progress, critical technical, design, and commercialization barriers persist, such as low power output, narrow operational bandwidth, reliability concerns, and stringent biocompatibility requirements. Further impeding widespread adoption are manufacturing costs, regulatory hurdles, and market competition with conventional batteries. By addressing these challenges with material innovations, advanced modeling, and efficient power management circuits, VEHs can revolutionize self-powered wearables. Future success hinges on interdisciplinary collaboration to bridge lab research and commercial viability for autonomous healthcare integration. This work stands out by synthesizing a critical analysis of both the technological promises and the practical commercialization hurdles, providing a holistic roadmap for researchers and industry stakeholders aiming to make self-powered biomedical devices a clinical reality. • Explores the potential of vibration energy harvesters (VEHs) for sustainable healthcare. • Reviews mechanisms and material advancements with a focus on biocompatibility. • Highlights key breakthroughs in VEHs efficiency, miniaturization, and power output for medical applications. • Identifies critical challenges limiting market adoption and proposes solutions. • Outlines actionable steps to accelerate VEHs integration into real-world healthcare systems.

A generic M-phase, N-stage folded cross-coupled CMOS rectifier architecture for low-power RF energy harvesting

Low-frequency human motion energy harvesting with a tumbler-inspired triboelectric nanogenerator

A self-powered hybrid wind sensor based on electromagnetic energy harvesting and triboluminescent sensing

Microstructurally engineered MXene/Metal organic framework based hybrid nanogenerator for water energy harvesting and self-powered gas sensor

The global rise in energy demand, driven by modern lifestyles, necessitates more efficient wind energy harvesting. This research aims to determine the optimal blade angle for enhancing aerodynamic performance in Horizontal Axis Wind Turbines (HAWTs) under specific wind conditions. Computational and experimental analyses were conducted to evaluate lift and drag forces across different blade angles, focusing on maximizing moment and power output. The results identify 82° as the optimal blade angle for peak performance, with maximum moment observed at this angle for wind speeds of 3 m/s, 12.5 m/s, and 25 m/s. CFD simulations using ANSYS Fluent 17.0 with NACA aerofoils were validated through experiments, showing strong agreement between theoretical and experimental results. The study establishes a rated tip speed of 105 m/s for a 5 MW HAWT. By integrating experimental and computational approaches, this research provides valuable insights into the aerodynamic behavior of HAWTs, aiding in the development of efficient airfoils and blades to enhance energy generation. The findings highlight CFD's role as a cost-effective and time-efficient tool for assessing blade and wind characteristics, contributing to the optimization of wind energy systems and the advancement of sustainable energy solutions. • Integration of computational, theoretical, and experimental methods to optimize HAWT performance • Identification of optimal blade angles to enhance efficiency at low wind speeds • Analysis of wind turbine performance using ANSYS Fluent and wind tunnel experiments • Insights into the impact of wind speed variations on electricity production • Comprehensive evaluation of aerodynamic forces influencing HAWT performance

Magnetorheological elastomers: Experimental characterization and dependences of the inverse effect

As digital transformation continues to evolve, demand for battery-free sensors is rising. This study examines the manufacturing and energy-harvesting performance of magnetoelectric (ME) composites that combine piezoelectric and magnetostrictive materials using the aerosol deposition (AD) method, which enables room-temperature film fabrication. A barium titanate piezoelectric film was applied to a magnetostrictive clad plate of iron–cobalt (Fe–Co) and nickel (Ni). The composite, exposed to an alternating magnetic field, vibrated via magnetostrition. Voltage output and stored energy were measured to assess energy-harvesting capacity. Theoretical equations were derived for the optimal piezoelectric-film length and the corresponding harvested energy. Finite element analysis compared theoretical, numerical, and experimental results. The AD process preserved the magnetostrictive properties of the clad substrate while allowing coupled piezoelectric and magnetostrictive responses. The maximum harvested energy reached 193 nJ. Mechanical deformation of the piezoelectric film under alternating magnetic excitation generated an alternating voltage, confirming magnetic-to-electric energy conversion. The highest magnetoelectric voltage coefficient was 4.5 V·cm −1 ·Oe −1 (μV·m −1 ·T −1 ). Theory indicated that maximum power is obtained when the piezoelectric film covers two-thirds of the substrate length, a result supported by simulation and experiment. These findings demonstrate the practicality of AD-fabricated ME composites for compact, self-powered sensors in next-generation intelligent systems. • AD enabled room-temperature fabrication of magnetoelectric composites • BTO films on Fe-Co/Ni substrates preserved magnetostrictive properties • Maximum harvested energy of 193 nJ under alternating magnetic fields • Peak ME voltage coefficient of 4.5 V/cm·Oe achieved experimentally • Optimal piezoelectric film length is two-thirds of substrate length

Actinomorphic-structured nickel oxide/graphene composites treated with stearic acid on cellulose-based substrate for humidity-to-energy harvesting applications

Wearable pendulum-based triboelectric-electromagnetic hybrid generator for human motion energy harvesting and recognition