Device Performance Research Articles

Study on the influence law of vortex generating structure on heat transfer performance of heat storage device

Solar energy is emerging as a resilient and environmentally friendly energy source. Utilizing heat storage devices to capture solar energy not only reduces carbon emissions but also aligns with the broader goal of energy conservation. In the effort to optimize the heat transfer efficiency of trough solar heat storage devices, a comprehensive investigation was conducted. This study involved the systematic design and analysis of twelve distinct structures, each characterized by varying contact angles and eccentricities. It was observed that using a substantial contact angle of Δ=0.2R (θ=150°) induces a stable disturbance within the pipeline, thereby significantly enhancing the overall heat transfer performance. Building on this observation, seven different eccentric structures were systematically designed to further improve the heat exchange performance of the pipeline. The findings indicate that, particularly at high Reynolds numbers, the implementation of an eccentric structure markedly enhances the heat transfer performance of the pipeline. Additionally, when Δ=0.2R, it effectively contributes to the improvement in the efficiency of heat storage devices.

Dual-Functional group passivation to foster buried interface Cohesion for High-Performance perovskite photovoltaics

Despite receiving comparatively less attention, the bottom interface holds a vital role in both charge transfer and the stability of perovskite solar cells (PSCs). Herein, a novel approach involves the incorporation of the natural amino acid D-Methionine (D.M) into the bottom interface, aiming to enhance device performance by serving as a versatile interfacial bridge. The carboxyl group present in D.M serves to suppress surface defects such as oxygen vacancies, thereby significantly improving the optoelectronic properties of SnO2. Additionally, D.M has been found to promote the perovskite crystals growth, leading larger grains size and high-quality films, consequently lowering the defect density. As a result, PSCs demonstrate a notable improvement in open circuit voltage, fill factor and the short circuit current density, ultimately resulting to an enhanced power conversion efficiency from 22.7% to 25.39%. Moreover, the stability of D.M−modified devices is significantly enhanced, as evidenced by the retention of 95% of their initial PCE compared to 76% for the control devices.

Real-world data to support post-market safety and performance of embolization coils: evidence generation from a medical device manufacturer and data institute partnership

BackgroundRecognizing the limitations of pre-market clinical data, regulatory authorities have embraced total product lifecycle management with post-market surveillance (PMS) data to assess medical device safety and performance. One method of proactive PMS involves the analysis of real-world data (RWD) through retrospective review of electronic health records (EHR). Because EHRs are patient-centered and focused on providing tools that clinicians use to determine care rather than collecting information on individual medical products, the process of transforming RWD into real-world evidence (RWE) can be laborious, particularly for medical devices with broad clinical use and extended clinical follow-up. This study describes a method to extract RWD from EHR to generate RWE on the safety and performance of embolization coils.MethodsThrough a partnership between a non-profit data institute and a medical device manufacturer, information on implantable embolization coils’ use was extracted, linked, and analyzed from clinical data housed in an electronic data warehouse from the state of Indiana’s largest health system. To evaluate the performance and safety of the embolization coils, technical success and safety were defined as per the Society of Interventional Radiology guidelines. A multi-prong strategy including electronic and manual review of unstructured (clinical chart notes) and structured data (International Classification of Disease codes), was developed to identify patients with relevant devices and extract data related to the endpoints.ResultsA total of 323 patients were identified as treated using Cook Medical Tornado, Nester, or MReye embolization coils between 1 January 2014 and 31 December 2018. Available clinical follow-up for these patients was 1127 ± 719 days. Indications for use, adverse events, and procedural success rates were identified via automated extraction of structured data along with review of available unstructured data. The overall technical success rate was 96.7%, and the safety events rate was 5.3% with 18 major adverse events in 17 patients. The calculated technical success and safety rates met pre-established performance goals (≥ 85% for technical success and ≤ 12% for safety), highlighting the relevance of this surveillance method.ConclusionsGenerating RWE from RWD requires careful planning and execution. The process described herein provided valuable longitudinal data for PMS of real-world device safety and performance. This cost-effective approach can be translated to other medical devices and similar RWD database systems.

Functional Zwitterionic Polyurethanes as Gate Dielectrics for Organic Field‐Effect Transistors

AbstractThe development of polymeric dielectrics with a high dielectric constant is of great significance for flexible low‐voltage organic field‐effect transistors (OFETs). Herein, functional polyurethanes (PUs) with nitro and sulfobetaine zwitterionic groups are synthesized, and their electrical properties, mechanical properties, and the performances of OFET devices using these zwitterionic PUs as gate dielectrics are studied. Compared with sulfobetaine zwitterion‐containing PUs, nitro‐containing PUs (NO2‐PUs) show higher dielectric constant up to 6.5. Both zwitterionic PUs enhance the OFET performances, while the effect of NO2‐PU is more significant. Devices using NO2‐PU‐15 that contains 15 moL% nitro groups as the dielectric layer show the best performance and a threshold voltage (Vth) of as low as −0.02 V together with two orders’ increase of the mobility is observed, compared with the devices using PU without nitro groups. This study provides a new method to improve the dielectric constant of polymeric dielectrics, which is valuable for flexible/stretchable and wearable electronic devices.

Vortex Domain Wall Thermal Pinning and Depinning in a Constricted Magnetic Nanowire for Storage Memory Nanodevices

In this study, we investigate the thermal pinning and depinning behaviors of vortex domain walls (VDWs) in constricted magnetic nanowires, with a focus on potential applications in storage memory nanodevices. Using micromagnetic simulations and spin transfer torque, we examine the impacts of device temperature on VDW transformation into a transverse domain wall (TDW), mobility, and thermal strength pinning at the constricted area. We explore how thermal fluctuations influence the stability and mobility of domain walls within stepped nanowires. The thermal structural stability of VDWs and their pinning were investigated considering the effects of the stepped area depth (d) and its length (λ). Our findings indicate that the thermal stability of VDWs in magnetic stepped nanowires increases with decreasing the depth of the stepped area (d) and increasing nanowire thickness (th). For th ≥ 50 nm, the stability is maintained at temperatures ≥ 1200 K. In the stepped area, VDW thermal pinning strength increases with increasing d and decreasing λ. For values of d ≥ 100 nm, VDWs depin from the stepped area at temperatures ≥ 1000 K. Our results reveal that thermal effects significantly influence the pinning strength at constricted sites, impacting the overall performance and reliability of magnetic memory devices. These insights are crucial for optimizing the design and functionality of next-generation nanodevices. The stepped design offers numerous advantages, including simple fabrication using a single electron beam lithography exposure step on the resist. Additionally, adjusting λ and d allows for precise control over the pinning strength by modifying the dimensions of the stepped areas.

Characterization of Conventional Endovascular Devices in Treatment of Abdominal Aortic Aneurysms

Abstract Abdominal aortic aneurysms (AAA) are often repaired through an endovascular approach known as endovascular aneurysm repair (EVAR). The success and duration of these challenging procedures are primarily attributable to the accuracy and reliability of navigating corresponding interventional devices. This study investigates the performance of conventional nonsteerable and steerable catheters in EVAR procedures, focusing on two primary metrics: reachable workspace and gate cannulation success. We developed two abdominal aortic aneurysm (AAA) phantoms using patient CT images for our experiments. Under X-ray fluoroscopy guidance, the reachable workspace was quantified, and gate cannulation success rates, cannulation time, and fluoroscopy times were recorded for both nonsteerable and steerable catheters and were compared. We were unable to observe statistically significant differences between the two catheter types in overall cannulation success rates or fluoroscopy time. However, in challenging anatomical scenarios (particularly a more challenging gate location), the steerable catheter showed statistically significant advantages in success rates and cannulation times. While there were no statistical differences in reachable workspace between nonsteerable and steerable catheters when considering the whole aneurysm, segmented analysis showed that the steerable catheter performed better in the central region, and nonsteerable catheters performed better in the peripheral region. This study provides a systematic method for quantifying the performance of endovascular devices. The findings suggest that while steerable catheters may offer advantages in complex anatomical conditions, nonsteerable catheters are preferable in peripheral areas of the aneurysm. These insights can inform catheter selection in EVAR, potentially influencing device design and clinical practice.

Optimizing Optoelectronics Performance: Theoretical and Experimental study on ZnO Thin Film for Al/ZnO/p-Si Photodiode

Abstract In this study investigates the optimization of ZnO thin film photoelectric devices, specifically focusing on ZnO/p-Si heterojunction photosensitive devices and photodiodes (PDs) using Al contacts. Through an experimental and theoretical analysis approach aims to evaluate the effects of important parameters, including ZnO layer thickness, defect density, and contact materials, on PD’s efficiency. Numerical analysis simulations comparatively examine the experimentally fabricated device performance at a 5 nm ZnO layer thickness by balancing photon absorption and carrier formation while minimizing carrier transport limitations. Experimentally process, an Atomic Layer Deposition (ALD) system was used to grow ZnO interlayers on one side of the polished Si wafer. Then, Al metallic contacts were created on the ZnO layers using a hole array mask. The PDs were then subjected to electrical characterization using I-V and I-t measurements under various illumination densities. Al/ZnO/p-Si PD's device with active performance has been produced and analyzed with electrical parameters such as barrier height, photocurrent, spectral response, ideality factor and EQE were derived, analyzed and studied. In conclusion, this work provides a comprehensive understanding of the performance of Al/ZnO/p-Si PD at varying illumination intensities and offering a detailed analysis of key parameters influencing device efficiency for future optoelectronics applications.

Recent advances in microenvironment regulation for electrocatalysis

Abstract High-efficiency electrocatalysis could serve as the bridge that connects renewable energy technologies, hydrogen economy and carbon capture/utilization, promising a sustainable future for humankind. It is therefore of paramount significance to explore feasible strategies to modulate the relevant electrocatalytic reactions and optimize the device performances so as to promote their large-scale practical applications. Microenvironment regulation at the catalytic interface has been demonstrated capable of effectively enhancing the reaction rates and improving the selectivities for specific products. In this review we summarize the latest advances in microenvironment regulation in typical electrocatalytic processes (including water electrolysis, hydrogen–oxygen fuel cells, and carbon dioxide reduction) and the related in situ/operando characterization techniques and theoretical simulation methods. At the end of this article, we present an outlook on the development trends and possible future directions.

Advanced Materials for Energy Harvesting and Soft Robotics: Emerging Frontiers to Enhance Piezoelectric Performance and Functionality.

Piezoelectric energy harvesting captures mechanical energy from a number of sources, such as vibrations, the movement of objects and bodies, impact events, and fluid flow to generate electric power. Such power can be employed to support wireless communication, electronic components, ocean monitoring, tissue engineering, and biomedical devices. A variety of self-powered piezoelectric sensors, transducers, and actuators have been produced for these applications, however approaches to enhance the piezoelectric properties of materials to increase device performance remain a challenging frontier of materials research. In this regard, the intrinsic polarization and properties of materials can be designed or deliberately engineered to enhance the piezo-generated power. This review provides insights into the mechanisms of piezoelectricity in advanced materials, including perovskites, active polymers, and natural biomaterials, with a focus on the chemical and physical strategies employed to enhance the piezo-response and facilitate their integration into complex electronic systems. Applications in energy harvesting and soft robotics are overviewed by highlighting the primary performance figures of merits, the actuation mechanisms, and relevant applications. Key breakthroughs and valuable strategies to further improve both materials and device performance are discussed, together with a critical assessment of the requirements of next-generation piezoelectric systems, and future scientific and technological solutions.

Ag nanoparticles at p-Si/ MAPbI3 perovskite interface: improved photo responsivity and response speed in photodetection

Although enhanced performances of photovoltaic devices by embedding metal nanoparticals in charge transport layer, doping into active layer bulk, decorating the active layer surface, and inserting at the interface between semiconductor and the electrode were reported, the effect of incorporating metal NPs at the interface of single crystal semiconductor and perovskite is rarely tackled. Herein the effects of incorporating Ag nanoparticals (AgNPs) at p-Si/MAPbI3 perovskite interface on the photodiode performances were investigated. The results showed that compared with reference device (without AgNPs) the photoresponsivity of the device incorporating AgNPs is greatly improved with the exception for light with wavelengths fall in the spectral range where AgNPs have strong optical absorption. This effect is extremely significant for relatively shorter wavelengths in visible region, and a maximal improvement of around 10.6 times in photoresponsivity was achieved. The physical origin of the exception for spectral range that AgNPs have strong optical absorption is the cancelation of scatter resulted enhancement through AgNPs by band-to-band absorption resulted reduction of photocurrent, in which the generated electron has energy near the fermi level and the hole has large effective mass, which relax by nonradiative recombination, thus making not contribution to the photocurrent. More importantly, the AgNP decorated device showed much faster photo response speed than reference device, and a maximal improvement of around 7.9 times in rise and fall time was achieved. These findings provide a novel approach for high responsive and high speed detection for weak light.

Combining 5G New Radio, Wi-Fi, and LiFi for Industry 4.0: Performance Evaluation

Fifth-generation mobile networks (5G) are designed to support enhanced Mobile Broadband, Ultra-Reliable Low-Latency Communications, and massive Machine-Type Communications. To meet these diverse needs, 5G uses technologies like network softwarization, network slicing, and artificial intelligence. Multi-connectivity is crucial for boosting mobile device performance by using different Wireless Access Technologies (WATs) simultaneously, enhancing throughput, reducing latency, and improving reliability. This paper presents a multi-connectivity testbed from the 5G-CLARITY project for performance evaluation. MultiPath TCP (MPTCP) was employed to enable mobile devices to send data through various WATs simultaneously. A new MPTCP scheduler was developed, allowing operators to better control traffic distribution across different technologies and maximize aggregated throughput. Our proposal mitigates the impact of limitations on one path affecting others, avoiding the Head-of-Line blocking problem. Performance was tested with real equipment using 5GNR, Wi-Fi, and LiFi —complementary WATs in the 5G-CLARITY project—in both static and dynamic scenarios. The results demonstrate that the proposed scheduler can manage the traffic distribution across different WATs and achieve the combined capacities of these technologies, approximately 1.4 Gbps in our tests, outperforming the other MPTCP schedulers. Recovery times after interruptions, such as coverage loss in one technology, were also measured, with values ranging from 400 to 500 ms.

Design and Simulation of a High-Performance Tunneling Field Effect Transistor-Based Biosensor Using a Heterojunction Electron-Hole Bilayer

Abstract This study introduces a novel dielectrically-modulated heterojunction electron-hole bilayer tunnel field-effect transistor (DM-HEHBTFET) for bio-sensing applications. The device features a Ga0.85Sb0.15As/Ga0.8In0.2As heterojunction and a p-type pocket in the channel, achieving a remarkably low threshold voltage (VT) of 20 mV, an average subthreshold slope (SS) of 5.7 mV/dec, and a leakage current (IOFF) as low as 5 × 10⁻¹¹ A/μm. The staggered bandgap in the heterostructures enhances electric field control, enabling lower gate voltage operation. Furthermore, the strategically positioned nanogap cavities in non-overlapping regions of the top and bottom gates effectively mitigate gate control issues over the channel, ensuring improved device performance. A modified design, the modified DM-HEHBTFET, is also proposed, featuring source and drain regions engineered with Ga0.85Sb0.15As/Ga0.8In0.2As heterojunctions. This design mitigates leakage current and improves the average subthreshold slope (SS). For biomolecules with a dielectric constant of 12, the modified biosensor exhibits a drain current sensitivity (Scurrent) of 2.6e4, average SS=2.7 mV/dec, and IOFF=1e-12 A/μm. The device's performance is assessed by examining steric hindrance and band tailing effects. The modified biosensor outperforms recent DM-TFET biosensors, making it a promising candidate for low-power, high-switching speed bio-sensing.

Influence of silver nanoparticles on enhancing performance of optical absorption property in a perovskite solar cell

Abstract This report presents a mostly numerical investigation of solar absorptance enhancement in PSCs through solving partial differential equations. The designed structural device comprised five layers of the transparent conducting contact (ITO), the electron transport layer (TiO2), the active layer (CH3NH3PBI3) embedding with plasmonic silver nanoparticles (AgNPs), the hole transporting layer (NiO), and the back reflectors (Ag). The calculation results showed that the device performance was highly dependent on the particle size of AgNP, structural formation and the location of the AgNPs. Overall, the optimum particle radius was r=10 nm, located at the middle of the activated layer (z=0 nm), a 2 dimensional array of 2x2 particles per unit cell and an interparticle distance of 4 nm were achieved for the AgNPs in the activel layer (AL) of the PSCs with highest optical enhancement of η=1.24.

Interfacial Stabilization of Organic Electrochemical Transistors Conferred Using Polythiophene-Based Conjugated Block Copolymers with a Hydrophobic Coil Design.

The recent interest in developing low-cost, biocompatible, and lightweight bioelectronic devices has focused on organic electrochemical transistors (OECTs), which have the potential to fulfill these requirements. In this study, three types of poly(3-hexylthiophene) (P3HT)-based block copolymers (BCPs) incorporating different insulating blocks (poly(nbutyl acrylate) (PBA), polystyrene, and poly(ethylene oxide) (PEO)) were synthesized for application in OECTs. The morphological, crystallographic, and electrochemical properties of these BCPs are systematically investigated. Accordingly, P3HT-b-PBA demonstrates superior performance in the KCl-based aqueous electrolyte, with a higher product of mobility and capacitance (μC*) at 170 F s-1 cm-1 V-1 than that of the P3HT homopolymer at 58 F s-1 cm-1 V-1. P3HT-b-PBA exhibits better stability over 50 ON/OFF switching cycles than do other BCPs and P3HT homopolymers. With regard to the performance in the KPF6-based aqueous electrolyte, P3HT-b-PBA outperforms with a higher μC* of 9.2 F s-1 cm-1 V-1 than that of 8.6 F s-1 cm-1 V-1 observed from P3HT. Notably, both polymers exhibited almost no decay in device performance over 110 ON/OFF switching cycles. The strongly different performance of polymers in these two electrolytes is due to the side chain's hydrophobicity and interdigitated lamellar structures, thereby retarding the doping kinetics of the highly hydrated Cl- ions compared with the slightly hydrated PF6- ions. Concerning the improved performance of P3HT-b-PBA, this is attributed to its soft and hydrophobic backbone. Our morphological and crystallographic analyses reveal that P3HT-b-PBA experiences minimal structural disorder when swelled by the electrolyte, maintaining its original structure better than the P3HT homopolymer and the hydrophilic BCP of P3HT-b-PEO. The hydrophobic nature of P3HT-b-PBA contributes to the stability of its backbone structure, ensuring enhanced capacitance during the operation of the OECT operation. These findings provide reassurance about the stability and performance of P3HT-b-PBA in the field of OECT applications. In summary, this study represents the first exploration of P3HT-based BCPs for OECT applications and investigates their structure-performance relationships in mixed ionic-electronic conductors.

Инновационные магнитные наноматериалы для улучшения хранения энергии

Background: Finding effective energy storage technologies is crucial for transitioning to sustainable energy systems. Magnetic nanoparticles have emerged as options due to their distinctive magnetic characteristics, which can considerably improve the performance of energy storage systems. Objective: This research aims to investigate innovative magnetic nanoparticles and assess to increase the efficiency and capacity of energy storage systems. The emphasis is on developing materials with optimal magnetic characteristics and incorporating them into current energy storage methods. Methods: Co-precipitation and thermal breakdown were used to create a range of new magnetic nanomaterials. Vibrational sample magnetometry, X-ray diffraction, and cyclic voltammetry were used to determine these materials' magnetic characteristics, structural integrity, and electrochemical performance. Subsequent integration into supercapacitors and lithium-ion batteries was carried out to evaluate energy storage capacity. Results: The synthesized magnetic nanoparticles showed improved magnetic saturation and charge-discharge characteristics compared to standard materials. When used in supercapacitors, they increased capacitance by 20% and improved cycle stability by 25%. Similarly, these nanomaterials improved the energy density of lithium-ion batteries by 15% and increased their longevity by 30%. Conclusion: The unique magnetic nanoparticles created in this work significantly improve the performance of energy storage devices. The increased capacitance, energy density, and operational stability indicate that these materials for future energy storage applications. Further study is required to optimize these materials for commercial application and investigate their scalability and environmental effects.

Modulating the fracture behavior of interface cracks via electric field gradient in flexoelectric solids

Interface cracks seriously affect the performance and service life of layered electronic devices. At nanoscale, the electric field concentration can be generated at the tip of insulating cracks by solely applying a uniform electric field loading, resulting in a large electric field gradient and thus inducing a significant converse flexoelectric effect. The deformation generated by the converse flexoelectric effect is expected to achieve crack shielding, however, its mechanism is still not clear. In this paper, the role of electric field gradients on interface crack behavior is studied by the collocation mixed finite element method (MFEM) and the J-integral. The result shows that the electric field gradient generated by a uniform electric displacement loading can reduce the J-integral of crack tips, achieving crack shielding. The result provides new ideas for the study of failure assessment, nanoscale fracture experiment and others.

Топологические изоляторы в электронных и спинтронных устройствах

Background: Topological insulators (TIs) are materials with distinctive features, including insulating interiors and conducting surface states protected by time-reversal symmetry. These features make TIs extremely promising for electrical and spintronic device applications, where manipulating electron spin without charge transfer is advantageous. Objective: This study aims to investigate of TIs to improve the performance and efficiency of electrical and spintronic devices. We look at the special qualities of TIs that may be used to improve device functionality, such as reduced power consumption and higher operational speed. Methods: To investigate electron transport behaviour on the surfaces of different TIs, we used a mix of quantum mechanical models and experimental settings. Devices based on bismuth telluride (Bi2Te3) and thallium arsenide (TlAs) were built to test their performance in real-world applications. Results: TI devices showed considerable gains in spin transport efficiency and thermal stability compared to conventional materials. Spintronic devices based on TIs demonstrated a 50% reduction in energy usage and a 30% improvement in data processing speed. Conclusion: Including topological insulators in electrical and spintronic devices offers a promising path to more efficient and speedier technologies. Future research should concentrate on the scalable integration of TIs into commercial devices and the discovery of novel materials with topological insulating characteristic.

Pangenomic landscapes shape performances of a synthetic genetic circuit across Stutzerimonas species.

Engineering identical genetic circuits into different species typically results in large differences in performance due to the unique cellular environmental context of each host, a phenomenon known as the "chassis-effect" or "context-dependency". A better understanding of how genomic and physiological contexts underpin the chassis-effect will improve biodesign strategies across diverse microorganisms. Here, we combined a pangenomic-based gene expression analysis with quantitative measurements of performance from an engineered genetic inverter device to uncover how genome structure and function relate to the observed chassis-effect across six closely related Stutzerimonas hosts. Our results reveal that genome architecture underpins divergent responses between our chosen non-model bacterial hosts to the engineered device. Specifically, differential expression of the core genome, gene clusters shared between all hosts, was found to be the main source of significant concordance to the observed differential genetic device performance, whereas specialty genes from respective accessory genomes were not significant. A data-driven investigation revealed that genes involved in denitrification and components of trans-membrane transporter proteins were among the most differentially expressed gene clusters between hosts in response to the genetic device. Our results show that the chassis-effect can be traced along differences among the most conserved genome-encoded functions and that these differences create a unique biodesign space among closely related species.IMPORTANCEContemporary synthetic biology endeavors often default to a handful of model organisms to host their engineered systems. Model organisms such as Escherichia coli serve as attractive hosts due to their tractability but do not necessarily provide the ideal environment to optimize performance. As more novel microbes are domesticated for use as biotechnology platforms, synthetic biologists are urged to explore the chassis-design space to optimize their systems and deliver on the promises of synthetic biology. The consequences of the chassis-effect will therefore only become more relevant as the field of biodesign grows. In our work, we demonstrate that the performance of a genetic device is highly dependent on the host environment it operates within, promoting the notion that the chassis can be considered a design variable to tune circuit function. Importantly, our results unveil that the chassis-effect can be traced along similarities in genome architecture, specifically the shared core genome. Our study advocates for the exploration of the chassis-design space and is a step forward to empowering synthetic biologists with knowledge for more efficient exploration of the chassis-design space to enable the next generation of broad-host-range synthetic biology.

Field effect transistor biosensors for healthcare monitoring

AbstractThe burgeoning demand for healthcare monitoring has brought field effect transistor (FET) biosensors into the spotlight as a highly efficient detection technology. FET biosensors offer inherent advantages including high sensitivity, rapid response times, operational simplicity, integrability, and label‐free detection. These characteristics render them particularly well‐suited for detecting a diverse array of physiological parameters and biomarkers, thereby furnishing real‐time data crucial for personalized medicine and disease prevention. This review aims to elucidate recent advancements in FET biosensors within the realm of healthcare management encompassing several facets. Initially, this review systematically analyzes the device architecture, sensing mechanisms, and performance evaluation methods of FET biosensors to gain an in‐depth understanding of their operational principles and features. Subsequently, it focuses on the application of FET biosensors for detecting health‐related biomarkers encompassing nucleic acids, proteins, exosomes, viruses, etc. Lastly, the review presents engineered medical sensor prototypes predicated on FET biosensors, such as point‐of‐care testing devices, wearable sensors, and implantable sensors, underscoring their practical utility and potential in health management. In addition, the review addresses critical issues and prospects of using FET biosensors in healthcare monitoring, aiming to provide some references and insights for research and innovation in this field.

Assessment of thermochromic phantoms for characterizing microwave ablation devices.

Thermochromic gel phantoms provide a controlled medium for visual assessment of thermal ablation device performance. However, there are limited studies reporting on the comparative assessment of ablation profiles assessed in thermochromic gel phantoms against those in ex vivo tissue. The objective of this study was to compare microwave ablation zones in a thermochromic tissue-mimicking gel phantom and ex vivo bovine liver and to report on measurements of the temperature-dependent dielectric and thermal properties of the phantom. Thermochromic polyacrylamide phantoms were fabricated following a previously reported protocol. Phantom samples were heated to temperatures in the range of 20°C-90°C in a temperature-controlled water bath, and colorimetric analysis of images of the phantom taken after heating was used to develop a calibration between color changes and the temperature to which the phantom was heated. Using a custom, 2.45GHz water-cooled microwave ablation antenna, ablations were performed in fresh ex vivo liver and phantoms using 65W applied for 5min or 10min (n=3 samples in each medium for each power/time combination). Broadband (500MHz-6GHz) temperature-dependent dielectric and thermal properties of the phantom were measured over the temperature range of 22°C-100°C. Colorimetric analysis showed that the sharp change in gel phantom color commences at a temperature of 57°C. Short and long axes of the ablation zone in the phantom (as assessed by the 57°C isotherm) for 65W, 5min ablations were aligned with the extents of the ablation zone observed in ex vivo bovine liver. However, for the 65W, 10min setting, ablations in the phantom were on average 23.7% smaller in the short axis and 7.4 % smaller in the long axis than those observed in ex vivo liver. Measurements of the temperature-dependent relative permittivity, thermal conductivity, and volumetric heat capacity of the phantom largely followed similar trends to published values for ex vivo liver tissue. Thermochromic tissue-mimicking phantoms provides a controlled, and reproducible medium for comparative assessment of microwave ablation devices and energy delivery settings. However, ablation zone size and shapes in the thermochromic phantom do not accurately represent ablation sizes and shapes observed in ex vivoliver tissue for high energy delivery treatments (65W, 10min). One cause for this limitation is the difference in temperature-dependent thermal and dielectric properties of the thermochromic phantom compared to ex vivobovine liver tissue, as reported in the present study.