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This paper introduces a new method of electricity generation using a Wiegand sensor. The Wiegand sensor consists of a magnetic wire and a pickup coil wound around it. This sensor generates a pulse voltage of approximately 5 V and 20 µs width as an induced voltage in the pickup coil. The aim of this study is to generate a DC voltage of 5 V from the sensor, which is expected to be used as a power source in self-powered devices and battery-less modules. We report on the design and verification of a self-oscillating boost converter circuit in this paper. A DC voltage obtained by rectifying and smoothing the pulse voltage generated from the Wiegand sensor was boosted by the circuit. A stable DC output voltage in the order of 5 V for use as a power supply in electronics modules was successfully obtained. A quantitative analysis of the power generated by the Wiegand sensor revealed a suitable voltage-current range for application in self-powered devices and battery-less modules.

Currently, the applications of the Internet of Things (IoT) generate a large amount of sensor data at a very high pace, making it a challenge to collect and store the data. This scenario brings about the need for effective data compression algorithms to make the data manageable among tiny and battery-powered devices and, more importantly, shareable across the network. Additionally, considering that, very often, wireless communications (e.g., low-power wide-area networks) are adopted to connect field devices, user payload compression can also provide benefits derived from better spectrum usage, which in turn can result in advantages for high-density application scenarios. As a result of this increase in the number of connected devices, a new concept has emerged, called TinyML. It enables the use of machine learning on tiny, computationally restrained devices. This allows intelligent devices to analyze and interpret data locally and in real time. Therefore, this work presents a new data compression solution (algorithm) for the IoT that leverages the TinyML perspective. The new approach is called the Tiny Anomaly Compressor (TAC) and is based on data eccentricity. TAC does not require previously established mathematical models or any assumptions about the underlying data distribution. In order to test the effectiveness of the proposed solution and validate it, a comparative analysis was performed on two real-world datasets with two other algorithms from the literature (namely Swing Door Trending (SDT) and the Discrete Cosine Transform (DCT)). It was found that the TAC algorithm showed promising results, achieving a maximum compression rate of 98.33%. Additionally, it also surpassed the two other models regarding the compression error and peak signal-to-noise ratio in all cases.

⿢Introducing the combination method of ENF and phase.⿢Producing a high accurate method for audio forgery detection.⿢Highly performance method for audio forgery detection in battery-powered devices.⿢Achieving 92% and 88% accuracy in laptop and mobile phone device, respectively. Audio forgery is any act of tampering, illegal copy and fake quality in the audio in a criminal way. In the last decade, there has been increasing attention to the audio forgery detection due to a significant increase in the number of forge in different type of audio. There are a number of methods for forgery detection, which electric network frequency (ENF) is one of the powerful methods in this area for forgery detection in terms of accuracy. In spite of suitable accuracy of ENF in a majority of plug-in powered devices, the weak accuracy of ENF in audio forgery detection for battery-powered devices, especially in laptop and mobile phone, can be consider as one of the main obstacles of the ENF. To solve the ENF problem in terms of accuracy in battery-powered devices, a combination method of ENF and phase feature is proposed. From experiment conducted, ENF alone give 50% and 60% accuracy for forgery detection in mobile phone and laptop respectively, while the proposed method shows 88% and 92% accuracy respectively, for forgery detection in battery-powered devices. The results lead to higher accuracy for forgery detection with the combination of ENF and phase feature.

The dream of human beings for long living has stimulated the rapid development of biomedical and healthcare equipment. However, conventional biomedical and healthcare devices have shortcomings such as short service life, large equipment size, and high potential safety hazards. Indeed, the power supply for conventional implantable device remains predominantly batteries. The emerging nanogenerators, which harvest micro/nanomechanical energy and thermal energy from human beings and convert into electrical energy, provide an ideal solution for self‐powering of biomedical devices. The combination of nanogenerators and biomedicine has been accelerating the development of self‐powered biomedical equipment. This article first introduces the operating principle of nanogenerators and then reviews the progress of nanogenerators in biomedical applications, including power supply, smart sensing, and effective treatment. Besides, the microbial disinfection and biodegradation performances of nanogenerators have been updated. Next, the protection devices have been discussed such as face mask with air filtering function together with real‐time monitoring of human health from the respiration and heat emission. Besides, the nanogenerator devices have been categorized by the types of mechanical energy from human beings, such as the body movement, tissue and organ activities, energy from chemical reactions, and gravitational potential energy. Eventually, the challenges and future opportunities in the applications of nanogenerators are delivered in the conclusive remarks. The combination of nanogenerator and biomedicine have been accelerating the development of self‐powered biomedical devices, which show a bright future in biomedicine and healthcare such as smart sensing, and therapy.

Most self‐powered electrochemical sensors (SPESs) are limited by low open circuit voltage and power density, leading to a narrow detection range and low sensitivity. Herein, a photoinduced Zn‐air battery‐assisted SPES (ZAB‐SPES) is proposed based on cobalt and sulfur co‐doped carbon nitride with the cyano group (Co, S‐CN). The cyano functionalization remarkably enhances visible light utilization, and the cyano moiety acts as an electron‐withdrawing group to promote electron enrichment. Co and S co‐doping can create a p–n homojunction within carbon nitride, enabling the efficient migration and separation of carriers, thereby significantly improving the performance of the oxygen reduction reaction. The synergistic effects endow Co, S‐CN photocathode with an open circuit voltage of 1.85 V and the maximum power density of 43.5 µW cm−2 in the photoinduced ZAB. Employing heavy metal copper ions as the target model, the photoinduced ZAB‐SPES exhibited dual‐mode and sensitive detection. Furthermore, a portable detection device based on the photoinduced ZAB‐SPES is designed and exhibits high linearity in the range of 5 ~ 600 nM with a detection limit of 1.7 nM. This work offers a portable detection method based on the photoinduced ZAB‐SPES in the aquatic environment. A photoinduced Zn‐air battery‐assisted self‐powered electrochemical sensor (ZAB‐SPES) is proposed based on cobalt and sulfur co‐doped carbon nitride with the cyano group (Co, S‐CN). Co, S‐CN photocathode possesses excellent performance of the photoinduced ZAB with an open circuit voltage of 1.85 V. A device is designed for achieving portable and on‐site detection of Cu(II) in the aquatic environment.

Multi‐functional actuation systems involve the mechanical integration of multiple actuation and sensor devices with external energy sources. The intricate combination makes it difficult to meet the requirements of lightweight. Hence, polypyrrole@graphene‐bacterial cellulose (PPy@G‐BC) films are proposed to construct multi‐responsive and bilayer actuators integrated with multi‐mode self‐powered sensing function. The PPy@G‐BC film not only exhibits good photo‐thermoelectric (PTE) properties but also possesses good hydrophilicity and high Young's modulus. Thus, the PPy@G‐BC films are used as active layers in multi‐responsive bilayer actuators integrated with self‐powered sensing functions. Here, two types of multi‐functional actuators integrated with self‐powered sensing functions is designed. One is a light‐driven actuator that realizes the self‐powered temperature sensing function through the PTE effect. Assisted by a machine learning algorithm, the self‐powered bionic hand can realize intelligent gesture recognition with an accuracy rate of 96.8%. The other is humidity‐driven actuators integrated a zinc‐air battery, which can realize self‐powered humidity sensing. Based on the above advantages, these two multi‐functional actuators are ingeniously integrated into a single device, which can simultaneously perform self‐powered temperature/humidity sensing while grasping objects. The highly integrated design enables the efficient utilization of environmental energy sources and complementary synergistic monitoring of multiple physical properties without increasing system complexity. Polypyrrole@graphene‐bacterial cellulose films are proposed to construct multi‐responsive actuators integrated with self‐powered and multi‐mode sensing function. Two types of multi‐functional actuators are ingeniously integrated into a single device, which can simultaneously perform self‐powered temperature/humidity sensing while grasping objects. The highly integrated design enables the efficient utilization of environmental energy sources and complementary synergistic monitoring of multiple physical properties.

The integration of electrochromic devices and energy storage systems in wearable electronics is highly desirable yet challenging, because self‐powered electrochromic devices often require an open system design for continuous replenishment of the strong oxidants to enable the coloring/bleaching processes. A self‐powered electrochromic device has been developed with a close configuration by integrating a Zn/MnO2 ionic battery into the Prussian blue (PB)‐based electrochromic system. Zn and MnO2 electrodes, as dual shared electrodes, the former one can reduce the PB electrode to the Prussian white (PW) electrode and serves as the anode in the battery; the latter electrode can oxidize the PW electrode to its initial state and acts as the cathode in the battery. The bleaching/coloring processes are driven by the gradient potential between Zn/PB and PW/MnO2 electrodes. The as‐prepared Zn||PB||MnO2 system demonstrates superior electrochromic performance, including excellent optical contrast (80.6%), fast self‐bleaching/coloring speed (2.0/3.2 s for bleaching/coloring), and long‐term self‐powered electrochromic cycles. An air‐working Zn||PB||MnO2 device is also developed with a 70.3% optical contrast, fast switching speed (2.2/4.8 s for bleaching/coloring), and over 80 self‐bleaching/coloring cycles. Furthermore, the closed nature enables the fabrication of various flexible electrochromic devices, exhibiting great potentials for the next‐generation wearable electrochromic devices. A self‐powered Zn||PB||MnO2 electrochromic device based on a shared electrode design and featuring a closed configuration, has been developed, which consists of a Prussian blue (PB) based electrochromic system and a zinc‐ion battery (ZIB). Both the bleaching and coloring processes are driven by the gradient potentials between Zn/PB and PW/MnO2 electrodes instead of external power supply. Owning to the closed nature of Zn||PB||MnO2 electrochromic system, a range of integrated flexible electrochromic devices are successfully fabricated, including electrochromic glasses, labels, and wristbands, exhibiting great potentials for the next‐generation wearable electrochromic devices.

Introduction: Neurological injuries significantly impair quality of life by disrupting neural transmission. Traditional implantable stimulators often rely on internal batteries, which limit device longevity and necessitate repeated surgical interventions. Objective: This study presents the experimental validation of a battery-free, RFID-powered neural platform for peripheral nerve signal acquisition and stimulation, targeting TRL-6 validation. Methods: The prototype incorporates an adjustable analog front-end with gains up to 93 dB and a biphasic current-controlled stimulator. Validation was performed through benchtop testing, biological tissue assessments using porcine tissue, and functional in vivo trials in adult Wistar rats (n = 3) over a three-month period. Results: Benchtop evaluation confirmed gain accuracy with errors below 2.2 dB and precise stimulation timing. The system maintained a stable 3.3 V wireless power link through 20 mm of biological tissue using RFID. In vivo experiments indicated a 100% functional success rate (51/51 trials) in eliciting gross motor responses via wireless stimulation. Thermal safety was confirmed, with a maximum operating temperature of 28 °C, remaining well below physiological limits. Conclusions: The results demonstrate the functional feasibility of a battery-free, RFID-powered neural interface for wireless signal acquisition and stimulation, supporting system-level validation of this architecture.

In recent years, tremendous research interest has been triggered in the fields of flexible, wearable and miniaturized power supply devices and self-powered energy sources, in which energy harvesting/conversion devices are integrated with energy storage devices into an infinitely self-powered energy system. As opposed to conventional fabrication methods, printing techniques hold promising potency for fabrication of power supply devices with practical scalability and versatility, especially for applications in wearable and portable electronics. To further enhance the performance of the as-fabricated devices, the utilization of nanomaterials is one of the promising strategies, owing to their unique properties. In this review, an overview on the progress of printable strategies to revolutionize the fabrication of power supply devices and integrated system with attractive form factors is provided. The advantages and limitations of the commonly adopted printing techniques for power supply device fabrication are first summarized. Thereafter, the research progress on novel developed printable energy harvesting and conversion devices, including solar cells, nanogenerators and biofuel cells, and the research advances on printable energy storage devices, namely, supercapacitors and rechargeable batteries, are presented, respectively. Although exciting advances on printable material modification, innovative fabrication methods and device performance improvement have been witnessed, there are still several challenges to be addressed to realize fully printable fabrication of integrated self-powered energy sources.

This study presents a compact and high-efficiency microstrip antenna integrated with a square electromagnetic band-gap (EBG) structure for radio frequency energy harvesting to power battery-less Internet of Things (IoT) sensors and medical devices in the 5.8 GHz Industrial, Scientific, and Medical (ISM) band. The proposed antenna features a compact design with reduced physical dimensions of 36 × 40 mm2 (0.69λo × 0.76λo) while providing high-performance parameters such as a reflection coefficient of −27.9 dB, a voltage standing wave ratio (VSWR) of 1.08, a gain of 7.91 dBi, directivity of 8.1 dBi, a bandwidth of 188 MHz, and radiation efficiency of 95.5%. Incorporating EBG cells suppresses surface waves, enhances gain, and optimizes impedance matching through 50 Ω inset feeding. The simulated and measured results of the designed antenna show a high correlation. This study demonstrates a robust and promising solution for high-performance wireless systems requiring a compact size and energy-efficient operation.