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Achieving negative surgical margins, defined as no tumor found on the edges of the resected tissue, during lumpectomy for breast cancer is critical for mitigating the risk of local recurrence. To identify nonpalpable tumors that cannot be felt, pre-operative placements of wire and wire-free localization devices are typically employed. Wire-free localization approaches have significant practical advantages over wired techniques. In this study, we introduce an innovative localization system comprising a light-emitting diode (LED)-based implantable device and handheld system. The device, which is needle injectable and wire free, utilizes multiple wirelessly powered LEDs to provide direct visual guidance for lumpectomy. Two distinct colors, red and blue, provide a clear indication of tissue depth: blue light is absorbed strongly in tissue, visible within a close range of <1 cm, while red light remains visible through several centimeters of tissue. The LEDs, integrated with an impedance-matching circuit and receiver coil, are encapsulated in biocompatible epoxy for injection with a 12 G needle. Our findings demonstrate that the implant exhibits clearly perceivable depth-dependent color changes and remains visible through >2 cm of ex vivo chicken breast and bovine muscle tissue using less than 4 W of transmitted power from a handheld antenna. These miniaturized needle-injectable localization devices show promise for improving surgical guidance of nonpalpable breast tumors.

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The influence of weak radio-frequency electromagnetic field (RF-EMF) on living organisms raises new concern because of the Industrial, Scientific, and Medical (ISM) frequency band at 6.78 MHz being promoted by the AirFuel Alliance for mid-range wireless power transfer (WPT) applications and product development. Human exposure to the RF-EMF radiation is unavoidable. In this study, we employed in vitro cell culture and molecular biology approach coupled with integrated transcriptomic and proteomic analyses to uncover the effects of RF-EMF on cells at molecular and cellular levels. Our study has demonstrated that weak RF-EMF is sufficient to exert non-thermal effects on human umbilical vein endothelial cells (HUVEC). Exposure of weak RF-EMF promotes cell proliferation, inhibits apoptosis and deregulates ROS balance. Alteration of several signaling pathways and key enzymes involved in NADPH metabolism, cell proliferation and ferroptosis were identified. Our current study provide solid evidence for the first time that the present safety standards that solely considered the thermal effect of RF-EMF on cell tissue are inadequate, prompt response and modification of existing Guidelines, Standards and Regulation are warranted.

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Inductive links represent a highly promising avenue for both powering and communicating medical implants. Yet they encounter challenges such as constrained communication distance and limited data rate. In Load Shift Keying (LSK), a switch in the secondary side of the inductive link can be placed in parallel with the load (Short-Circuit Technique - SCT), in series with the load (Open-Circuit Technique - OCT), or both (Dual Technique - DLT), to vary the impedance of the secondary. Hence, the impedance reflected to the primary side changes and is used to transmit information externally from the implant. Among these, DLT is a novel LSK technique proposed in this work, which becomes independent from the load on the implant side. This study compares these three methods, confronting measurements to simulations. The evaluation focused on variations in coil distance and load. The proposal is illustrated in the case of an implantable gastric stimulator, with specific constraints in secondary coil size and power requirements. The newly developed DLT consistently outshone SCT and OCT in extending the operational range of communication, registering a maximum modulation index of 0.797 and a bit error rate below 10- 7 at an operating distance of 95 mm through the air. Its load-independent characteristic allowed DLT to surpass the performance of SCT and OCT, which were each advantageous under high and low loads, respectively. All these results are confirmed by a LTSpice simulation. Consequently, the communication techniques put forward in this work mark a significant progression in medical implant communications, enhancing coil-to-coil operational distance while adhering to a low carrier frequency.

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Implantable medical devices (IMDs), like pacemakers regulating heart rhythm or deep brain stimulators treating neurological disorders, revolutionize healthcare. However, limited battery life necessitates frequent surgeries for replacements. Ultrasound power transfer (UPT) emerges as a promising solution for sustainable IMD operation. Current research prioritizes implantable materials, with less emphasis on sound field analysis and maximizing energy transfer during wireless power delivery. This review addresses this gap. A comprehensive analysis of UPT technology, examining cutting-edge system designs, particularly in power supply and efficiency is provided. The review critically examines existing efficiency models, summarizing the key parameters influencing energy transmission in UPT systems. For the first time, an energy flow diagram of a general UPT system is proposed to offer insights into the overall functioning. Additionally, the review explores the development stages of UPT technology, showcasing representative designs and applications. The remaining challenges, future directions, and exciting opportunities associated with UPT are discussed. By highlighting the importance of sustainable IMDs with advanced functions like biosensing and closed-loop drug delivery, as well as UPT's potential, this review aims to inspire further research and advancements in this promising field.

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Wearable and implantable active medical devices (WIMDs) are transformative solutions for improving healthcare, offering continuous health monitoring, early disease detection, targeted treatments, personalized medicine, and connected health capabilities. Commercialized WIMDs use primary or rechargeable batteries to power their sensing, actuation, stimulation, and communication functions, and periodic battery replacements of implanted active medical devices pose major risks of surgical infections or inconvenience to users. Addressing the energy source challenge is critical for meeting the growing demand of the WIMD market that is reaching valuations in the tens of billions of dollars. This review critically assesses the recent advances in energy harvesting and storage technologies that can potentially eliminate the need for battery replacements. With a key focus on advanced materials that can enable energy harvesters to meet the energy needs of WIMDs, this review examines the crucial roles of advanced materials in improving the efficiencies of energy harvesters, wireless charging, and energy storage devices. This review concludes by highlighting the key challenges and opportunities in advanced materials necessary to achieve the vision of self-powered wearable and implantable active medical devices, eliminating the risks associated with surgical battery replacement and the inconvenience of frequent manual recharging.

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Reliable testing of aviation components depends on the quality and configuration flexibility of measurement systems. In a typical approach to test instrumentation, there are tens or hundreds of sensors on the test head and test facility, which are connected by wires to measurement cards in control cabinets. The preparation of wiring and the setup of measurement systems are laborious tasks requiring diligence. The use of smart wireless transducers allows for a new approach to test preparation by reducing the number of wires. Moreover, additional functionalities like data processing, alarm-level monitoring, compensation, or self-diagnosis could improve the functionality and accuracy of measurement systems. A combination of low power consumption, wireless communication, and wireless power transfer could speed up the test-rig instrumentation process and bring new test possibilities, e.g., long-term testing of moving or rotating components. This paper presents the design of a wireless smart transducer dedicated for use with sensors typical of aviation laboratories such as thermocouples, RTDs (Resistance Temperature Detectors), strain gauges, and voltage output integrated sensors. The following sections present various design requirements, proposed technical solutions, a study of battery and wireless power supply possibilities, assembly, and test results. All presented tests were carried out in the Components Test Laboratory located at the Lukasiewicz Research Network-Institute of Aviation.

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As implantable medical electronics (IMEs) developed for healthcare monitoring and biomedical therapy are extensively explored and deployed clinically, the demand for non-invasive implantable biomedical electronics is rapidly surging. Current rigid and bulky implantable microelectronic power sources are prone to immune rejection and incision, or cannot provide enough energy for long-term use, which greatly limits the development of miniaturized implantable medical devices. Herein, a comprehensive review of the historical development of IMEs and the applicable miniaturized power sources along with their advantages and limitations is given. Despite recent advances in microfabrication techniques, biocompatible materials have facilitated the development of IMEs system toward non-invasive, ultra-flexible, bioresorbable, wireless and multifunctional, progress in the development of minimally invasive power sources in implantable systems has remained limited. Here three promising minimally invasive power sources summarized, including energy storage devices (biodegradable primary batteries, rechargeable batteries and supercapacitors), human body energy harvesters (nanogenerators and biofuel cells) and wireless power transfer (far-field radiofrequency radiation, near-field wireless power transfer, ultrasonic and photovoltaic power transfer). The energy storage and energy harvesting mechanism, configurational design, material selection, output power and in vivo applications are also discussed. It is expected to give a comprehensive understanding of the minimally invasive power sources driven IMEs system for painless health monitoring and biomedical therapy with long-term stable functions.

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Wireless charging of Electric Vehicles (EVs) has been extensively researched in the realm of electric cars, offering a convenient method. Nonetheless, there has been a scarcity of experiments conducted on low-power electric vehicles. To establish a wireless power transfer system for an electric vehicle, optimal power and transmission efficiency necessitate arranging the coils coaxially. In wireless charging systems, coils often experience angular and lateral misalignments. In this paper, a new alignment strategy is introduced to tackle the misalignment problem between the transmitter and receiver coils in the wireless charging of Electric Vehicles (EVs). The study involves the design and analysis of a coil, considering factors such as mutual inductance and efficiency. Wireless coils with angular misalignment are modelled in Ansys Maxwell simulation software. The proposed practical EV system aims to align the coils using angular motion, effectively reducing misalignment during the parking of two-wheelers. This is achieved by tilting the transmitter coil in the desired direction. Furthermore, micro sensing coils are employed to identify misalignment and facilitate automatic alignment. Additionally, adopting a power control technique becomes essential to achieve both constant current (CC) and constant voltage (CV) modes during battery charging. Integrating CC and CV modes is crucial for efficiently charging lithium-ion batteries, ensuring prolonged lifespan and optimal capacity utilization. The developed system can improve the efficiency of the wireless charging system to 90.3% with a 24 V, 16 Ah Lithium Ion Phosphate (LiFePO4) battery at a 160 mm distance between the coils.

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Objective.The wireless transfer of power for driving implantable neural stimulation devices has garnered significant attention in the bioelectronics field. This study explores the potential of photovoltaic (PV) power transfer, utilizing tissue-penetrating deep-red light-a novel and promising approach that has received less attention compared to traditional induction or ultrasound techniques. Our objective is to critically assess key parameters for directly powering neurostimulation electrodes with PVs, converting light impulses into neurostimulation currents.Approach.We systematically investigate varying PV cell size, optional series configurations, and coupling with microelectrodes fabricated from a range of materials such as Pt, TiN, IrOx, Ti, W, PtOx, Au, or poly(3,4 ethylenedioxythiophene):poly(styrene sulfonate). Additionally, two types of PVs, ultrathin organic PVs and monocrystalline silicon PVs, are compared. These combinations are employed to drive pairs of electrodes with different sizes and impedances. The readout method involves measuring electrolytic current using a straightforward amplifier circuit.Main results.Optimal PV selection is crucial, necessitating sufficiently large PV cells to generate the desired photocurrent. Arranging PVs in series is essential to produce the appropriate voltage for driving current across electrode/electrolyte impedances. By carefully choosing the PV arrangement and electrode type, it becomes possible to emulate electrical stimulation protocols in terms of charge and frequency. An important consideration is whether the circuit is photovoltage-limited or photocurrent-limited. High charge-injection capacity electrodes made from pseudo-faradaic materials impose a photocurrent limit, while more capacitive materials like Pt are photovoltage-limited. Although organic PVs exhibit lower efficiency than silicon PVs, in many practical scenarios, stimulation current is primarily limited by the electrodes rather than the PV driver, leading to potential parity between the two types.Significance.This study provides a foundational guide for designing a PV-powered neurostimulation circuit. The insights gained are applicable to bothin vitroandin vivoapplications, offering a resource to the neural engineering community.

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Haptic technology permeates diverse fields and is receiving renewed attention for VR and AR applications. Advances in flexible electronics, facilitate the integration of haptic technologies into soft wearable systems, however, because of small footprint requirements face challenges of operational time requiring either large batteries, wired connections or frequent recharge, restricting the utility of haptic devices to short-duration tasks or low duty cycles, prohibiting continuously assisting applications. Currently many chronic applications are not investigated because of this technological gap. Here, we address wireless power and operation challenges with a biosymbiotic approach enabling continuous operation without user intervention, facilitated by wireless power transfer, eliminating the need for large batteries, and offering long-term haptic feedback without adhesive attachment to the body. These capabilities enable haptic feedback for robotic surgery training and posture correction over weeks of use with neural net computation. The demonstrations showcase that this device class expands use beyond conventional brick and strap or epidermally attached devices enabling new fields of use for imperceptible therapeutic and assistive haptic technologies supporting care and disease management.

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Ultrasonic waves can be used to transfer power and data efficiently through metallic enclosures when feedthroughs are not practical due to structural or electromagnetic shielding considerations. Previous implementations of ultrasonic power transfer (UPT) used a piezoelectric transducer permanently bonded to the metal for efficient ultrasonic coupling. For portable operation, it is essential to have a detachable transmitter (charger) that is only attached to the enclosure while transferring power. This requirement presents several design challenges; notably, detachable ultrasonic coupling typically relies on liquid or gel couplant, which may become inconvenient or less robust during repeated attachment and detachment. Thus, this work develops a dry-coupled detachable UPT system to transfer power efficiently through a metallic enclosure without the need for a liquid couplant. Low attenuation soft elastomers are experimentally tested with a magnetic setup to evaluate their dry-coupled efficiency. Samples with different materials and thicknesses are experimentally tested to select the best configuration for dry ultrasonic coupling. The softest elastomer tested yielded the best ultrasonic efficiency (AC-to-AC) of 68% at 1 MHz. A full DC-to-DC portable (battery-operated) UPT system was then developed and experimentally characterized. The system was capable of delivering up to 3 W of DC power to a resistive load with a total efficiency of 50%.

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We present a 100 µm-thick, wireless, and battery-free implant for brain stimulation through a U.S. Food and Drug Administration-approved collagen dura substitute without contact with the brain's surface, while providing visible-light spectrum telemetry to track the onset of stimulation. The device is fabricated on a 16 × 6.67 mm2 biocompatible parylene/PDMS substrate and is encapsulated with a 2 µm-thick transparent parylene layer that enables the relay of the LED brightness. The in vivo rodent testing confirmed the implant's ability to trigger motor response while generating observable brightness through the skin. The results reveal the prospect of wireless stimulation with enhanced safety by eliminating contact between the implant and the brain, with optical telemetry for facilitated tracking.

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Wireless power transfer (WPT) technology is a contactless wireless energy transfer method with wide-ranging applications in fields such as smart homes, the Internet of Things (IoT), and electric vehicles. Achieving optimal efficiency in wireless power transfer systems has been a key research focus. In this paper, we propose a tracking method based on full current mode impedance matching for optimizing wireless power transfer efficiency. This method enables efficiency tracking in WPT systems and seamless switching between continuous conduction mode and discontinuous mode, expanding the detection capabilities of the wireless power transfer system. MATLAB was used to simulate the proposed method and validate its feasibility and effectiveness. Based on the simulation results, the proposed method ensures optimal efficiency tracking in wireless power transfer systems while extending detection capabilities, offering practical value and potential for widespread applications.

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The global need for energy is increasing at a high rate and is expected to double or increase by 50%, according to some studies, in 30 years. As a result, it is essential to look into alternative methods of producing power. Solar photovoltaic (PV) power plants utilize the sun's clean energy, but they're not always dependable since they depend on weather patterns and requires vast amount of land. Space-based solar power (SBSP) has emerged as the potential solution to this issue. SBSP can provide 24/7 baseload carbon-free electricity with power density over 10 times greater than terrestrial alternatives while requiring far less land. Solar power is collected and converted in space to be sent back to Earth via Microwave or laser wirelessly and used as electricity. However, harnessing its full potential necessitates tackling substantial technological obstacles in wireless power transmission across extensive distances in order to efficiently send power to receivers on the ground. When it comes to achieving a net-zero goal, the SBSP is becoming more viable option. This paper presents a review of wireless power transmission systems and an overview of SBSP as a comprehensive system. To introduce the state-of-the-art information, the properties of the system and modern SBSP models along with application and spillover effects with regard to different sectors was examined. The challenges and risks are discussed to address the key barriers for successful project implementation. The technological obstacles stem from the fact that although most of the technology is already available none are actually efficient enough for deployment so with, private enterprises entering space race and more efficient system, the cost of the entire system that prevented this notion from happening is also decreasing. With incremental advances in key areas and sustained investment, SBSP integrated with other renewable could contribute significantly to cross-sector decarbonization.

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The design and optimization of an electromagnetic wave absorber for far-field wireless power transmission (WPT) is the subject of this research study. The goal of the research is to effectively absorb energy from ambient RF electromagnetic waves without the usage of a ground plane by employing metasurfaces with chiral components.By integrating trioidal moments into the design theory, the objective is to create a metasurface that functions in two frequency bands and produces high-quality resonance. The study also explores the dual non-homogeneity property of structures, polarization tensor coefficients, and the electromagnetic response of non-homogeneous metasurfaces. Based on the relative orientation of induced fields and moments, it delves deeper into the two basic possibilities for dual non-homogeneous elements. The development of chiral metasurfaces and the notion of electromagnetic chirality and its implications for polarization properties are introduced.

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Early diagnosis of gastrointestinal (GI) diseases is important to effectively prevent carcinogenesis. Capsule endoscopy (CE) can address the pain caused by wired endoscopy in GI diagnosis. However, existing CE approaches have difficulty effectively diagnosing lesions that do not exhibit obvious morphological changes. In addition, the current CE cannot achieve wireless energy supply and attitude control at the same time. Here, we successfully developed a novel near-infrared fluorescence capsule endoscopy (NIFCE) that can stimulate and capture near-infrared (NIR) fluorescence images to specifically identify subtle mucosal microlesions and submucosal lesions while capturing conventional white light (WL) images to detect lesions with significant morphological changes. Furthermore, we constructed the first synergetic system that simultaneously enables multi-attitude control in NIFCE and supplies long-term power, thus addressing the issue of excessive power consumption caused by the NIFCE emitting near-infrared light (NIRL). We performed in vivo experiments to verify that the NIFCE can specifically "light up" tumors while sparing normal tissues by synergizing with probes actively aggregated in tumors, thus realizing specific detection and penetration. The prototype NIFCE system represents a significant step forward in the field of CE and shows great potential in efficiently achieving early targeted diagnosis of various GI diseases.

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In recent decades, we have seen significant technical progress in the modern world, leading to the widespread use of telecommunications systems, electrical appliances, and wireless technologies. These devices generate electromagnetic radiation (EMR) and electromagnetic fields (EMF) most often in the extremely low frequency or radio-frequency range. Therefore, they were included in the group of environmental risk factors that affect the human body and health on a daily basis. In this study, we tested the effect of exposure EMF generated by a new prototype wireless charging system on four human cell lines (normal cell lines-HDFa, NHA; tumor cell lines-SH-SY5Y, T98G). We tested different operating parameters of the wireless power transfer (WPT) device (87-207 kHz, 1.01-1.05 kW, 1.3-1.7 mT) at different exposure times (pulsed 6 × 10 min; continuous 1 × 60 min). We observed the effect of EMF on cell morphology and cytoskeletal changes, cell viability and mitotic activity, cytotoxicity, genotoxicity, and oxidative stress. The results of our study did not show any negative effect of the generated EMF on either normal cells or tumor cell lines. However, in order to be able to estimate the risk, further population and epidemiological studies are needed, which would reveal the clinical consequences of EMF impact.

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Wireless power transfer (WPT) within the human body can enable long-lasting medical devices but poses notable challenges, including absorption by biological tissues and weak coupling between the transmitter (Tx) and receiver (Rx). In pursuit of more robust and efficient wireless power, various innovative strategies have emerged to optimize power transfer efficiency (PTE). One such groundbreaking approach stems from the incorporation of metamaterials, which have shown the potential to enhance the capabilities of conventional WPT systems. In this review, we delve into recent studies focusing on WPT systems that leverage metamaterials to achieve increased efficiency for implantable medical devices (IMDs) in the electromagnetic paradigm. Alongside a comparative analysis, we also outline current challenges and envision potential avenues for future advancements.

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Millimeter-wave (mmWave) radars attain high resolution without compromising privacy while being unaffected by environmental factors such as rain, dust, and fog. This study explores the challenges of using mmWave radars for the simultaneous detection of people and small animals, a critical concern in applications like indoor wireless energy transfer systems. This work proposes innovative methodologies for enhancing detection accuracy and overcoming the inherent difficulties posed by differences in target size and volume. In particular, we explore two distinct positioning scenarios that involve up to four mmWave radars in an indoor environment to detect and track both humans and small animals. We compare the outcomes achieved through the implementation of three distinct data-fusion methods. It was shown that using a single radar without the application of a tracking algorithm resulted in a sensitivity of 46.1%. However, this sensitivity significantly increased to 97.10% upon utilizing four radars using with the optimal fusion method and tracking. This improvement highlights the effectiveness of employing multiple radars together with data fusion techniques, significantly enhancing sensitivity and reliability in target detection.

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This work originated from the demand presented by an electric power transmission company and addresses a possible solution for the sector by exploring alternatives to extend the flight time of drones in the inspection of transmission lines. This original article demonstrates the use of the electromagnetic field of a transmission line to generate useful electrical power at the terminals of a bulb containing argon gas. It is an unprecedented application in power transmission. In this work, the tests based on a proof of concept are documented, where the results obtained were satisfactory and still allowed to connect an LED through the constructed arrangement. It is observed that the continuity of this research can provide scalability for applications whose main source of ion excitation is given from the energy dissipated as electric field loss in high-voltage lines.