Investigation and comparison of the influence of modified DBR and yellow color filters for quantum dot color conversion-based micro LED applications.

This study compares how a modified distributed Bragg reflector (DBR) and yellow color filter (Y-CF) increase the color purity, viewing angle, and brightness of the quantum dot color conversion layer (QDCC) for micro-LED displays. We designed and built a 53-layer high-performance modified DBR with almost total blue leakage filtering (T %: 0.16 %) and very high G/R band transmittance (T %: 96.97 %) for comparison. We also use a Y-CF that filters blue light (T %: 0.84 %) and has good G/R band transmittance (T %: 94.83 %). Due to DBR's angle dependency effect, the modified DBR/QDCC structure offers a remarkable color gamut (117.41 % NTSC) at the forward viewing angle, but this rapidly diminishes beyond 30°. The Y-CF/QDCC structure retains 116 % NTSC color at all viewing angles. Because of its consistent color performance at all viewing angles, sufficient brightness, and outstanding color gamut, the Y-CF/QDCC structure is the best option for contemporary QDCC-based micro-LED displays.

Sexual dimorphism in the structural colours of the wings of the black soldier fly (BSF) Hermetia illucens (Diptera: Stratiomyidae).

The black soldier fly (BSF) Hermetia illucens (Diptera: Stratiomyidae) plays a significant role at the larval stage in the circular economy due to its ability to convert organic waste into valuable products for energy, food, feed, and agricultural applications. Many data are available on larval development and biomass generation, but basic research on this species is lacking and little is known about adult biology, in particular about the cues involved in sexual recognition. In the present study, using various instruments (stereomicroscope, scanning and transmission electron microscope, hyperspectral camera and spectrophotometer), wing ultrastructure of both sexes was analysed, reflectance and transmission spectra of the wings were measured and behavioural bioassays were carried out to measure male response to specific visual stimuli. The collected data showed the existence of sexual dimorphism in the wings of H. illucens due to iridescent structural colouration generated by a multilayer of melanin located in the dorsal lamina of the central part of the wing. Wing sexual dimorphism is particularly evident regarding the strong emission of blue light of female wings. Blue colour induces in males a strong motivation to mate. The obtained results can help to improve and optimize the breeding techniques of BSF.

Color Generation and Polarization-Sensitive Encryption by Laser Writing on Plasmonic Reflector Arrays.

Plasmonic color printing presents a sustainable solution for vibrant and durable color reproduction by leveraging the light-manipulating properties of nanostructures. However, the fabrication of plasmonic nanostructures has posed challenges, hindering widespread adoption. In this paper, we introduce plasmonic reflector arrays (PRAs) composed of three layers─Ag nanoparticles (NPs), an Al2O3 spacer, and an Ag reflector─deposited via physical vapor deposition (PVD). By employing nanosecond and femtosecond laser writing techniques, we manipulate the surface morphology of silver nanoparticles on PRAs, resulting in a diverse range of structural colors that are both polarization-insensitive and polarization-sensitive. Furthermore, we demonstrate the versatility of nanosecond laser writing in creating intricate patterns on PRAs. Additionally, we propose a novel two-step method combining nanosecond and femtosecond laser processing to embed QR code patterns into PRAs, showcasing their potential for secure data encryption and transmission. This research underscores the promising applications of PRAs in advanced color printing and secure optical data encoding.

SiNx/SiO2-Based Fabry-Perot Interferometer on Sapphire for Near-UV Optical Gas Sensing of Formaldehyde in Air.

Fabry-Perot interferometers (FPIs), comprising foundry-compatible dielectric thin films on sapphire wafer substrates, were investigated for possible use in chemical sensing. Specifically, structures comprising two vertically stacked distributed Bragg reflectors (DBRs), with the lower DBR between a sapphire substrate and a silicon-oxide (SiO2) resonator layer and the other DBR on top of this resonator layer, were investigated for operation in the near-ultraviolet (near-UV) range. The DBRs are composed of a stack of nitride-rich silicon-nitride (SiNx) layers for the higher index and SiO2 layers for the lower index. An exemplary application would be formaldehyde detection at sub-ppm concentrations in air, using UV absorption spectroscopy in the 300-360 nm band, while providing spectral selectivity against the main interfering gases, notably NO2 and O3. Although SiNx thin films are conventionally used only for visible and near-infrared optical wavelengths (above 450 nm) because of high absorbance at lower wavelengths, this work shows that nitride-rich SiNx is suitable for near-UV wavelengths. The interplay between spectral absorbance, transmittance and reflectance in a FPI is presented in a comparative study between one FPI design using stoichiometric material (Si3N4) and two designs based on N-rich compositions, SiN1.39 and SiN1.49. Spectral measurements confirm that if the design accounts for phase penetration depth, sufficient performance can be achieved with the SiN1.49-based FPI design for gas absorption spectroscopy in near-UV, with peak transmission at 330 nm of 64%, a free spectral range (FSR) of 20 nm and a full-width half-magnitude spectral resolution (FWHM) of 2 nm.

Visual Strain Sensors Based on Fabry-Perot Structures for Structural Integrity Monitoring.

Strain sensors that can rapidly and efficiently detect strain distribution and magnitude are crucial for structural health monitoring and human-computer interactions. However, traditional electrical and optical strain sensors make access to structural health information challenging because data conversion is required, and they have intricate, delicate designs. Drawing inspiration from the moisture-responsive coloration of beetle wing sheaths, we propose using Ecoflex as a flexible substrate. This substrate is coated with a Fabry-Perot (F-P) optical structure, comprising a "reflective layer/stretchable interference cavity/reflective layer", creating a dynamic color-changing visual strain sensor. Upon the application of external stress, the flexible interference chamber of the sensor stretches and contracts, prompting a blue-shift in the structural reflection curve and displaying varying colors that correlate with the applied strain. The innovative flexible sensor can be attached to complex-shaped components, enabling the visual detection of structural integrity. This biomimetic visual strain sensor holds significant promise for real-time structural health monitoring applications.

Enhancement of Light Efficiency of Deep-Ultraviolet Light-Emitting Diodes by Encapsulation with a 3D Photonic Crystal Reflecting Layer.

Recently, UVC LEDs, which emit deep ultraviolet light, have found extensive applications across various fields. This study demonstrates the design and implementation of thin films of three-dimensional photonic crystals (3D PhCs) as reflectors to enhance the light output power (LOP) of UVC LEDs. The 3D PhC reflectors were prepared using the self-assembly of silica nanospheres on a UVC LED lead frame substrate via the evaporation-induced method (side) and the gravitational sedimentation method (bottom), respectively. These PhCs with the (111) crystallographic plane were deposited on the side wall and bottom of the UVC LED lead frame, acting as functional materials to reflect UVC light. The LOP of UVC LEDs with 3D PhC reflectors at a driving current of 100 mA reached 19.6 mW. This represented a 30% enhancement compared to commercial UVC LEDs with Au-plated reflectors, due to the UVC light reflection by the photonic band gaps of 3D PhCs in the (111) crystallographic plane. Furthermore, after aging tests at 60 °C and 60% relative humidity for 1000 h, the relative LOP of UVC LEDs with 3D PhC reflectors decreased by 7%, which is better than that of commercial UVC LEDs. Thus, this study offers potential methods for enhancing the light output efficiency of commercial UVC light-emitting devices.

Wavelength Tuning in Resonant Cavity Interband Cascade Light Emitting Diodes (RCICLEDs) via Post Growth Cavity Length Adjustment.

We demonstrate substrate-emitting resonant cavity interband cascade light emitting diodes (RCICLEDs) based on a single distributed Bragg reflector (DBR). These devices operate in continuous wave mode at room temperature. Compared to standard ICLEDs without a cavity, we achieved an 89% reduction in the emission spectrum width, as indicated by the Full Width Half Maximum (FWHM) of 70 nm. Furthermore, we observed far-field narrowing and improved thermal stability. A single DBR configuration allows the cavity length to be adjusted by adding refractive index-matched material to the top of the epitaxial structure after epitaxial growth. This modification effectively shifts the cavity response towards longer wavelengths. We fabricated emitters comprising two cavities of different lengths, resulting in the emission of two distinct spectral lines that can be independently controlled. This dual-color capability enables one of the emission lines to serve as a built-in reference channel, making these LEDs highly suitable for cost-effective gas-sensing applications.

Light-Emitting-Diode-Induced Fluorescence from Organic Dyes for Application in Excitation-Emission Fluorescence Spectroscopy for Food System Analysis.

An experimental study is presented on the possibility of using the fluorescence from organic dyes as a broadband light source together with a monochromator for applications in excitation-emission matrix (EEM) fluorescence spectroscopy. A high-power single-chip light-emitting diode (LED) was chosen as an excitation source with a central output wavelength at 365 nm to excite a fluorescent solution of Coumarin 1 dye dissolved in ethanol. Two excitation configurations were investigated: direct excitation from the LED and excitation through an optical-fiber-coupled LED. A Czerny-Turner monochromator with a diffraction grating was used for the spectral tuning of the fluorescence. A simple method was investigated for increasing the efficiency of the excitation as well as the fluorescence signal collection by using a diffuse reflector composed of barium sulfate (BaSO4) and polyvinyl alcohol (PVA). As research objects, extra-virgin olive oil (EVOO), Coumarin 6 dye, and Perylene, a polycyclic aromatic hydrocarbon (PAH), were used. The results showed that the light-emitting-diode-induced fluorescence was sufficient to cover the losses on the optical path to the monochromator output, where a detectable signal could be obtained. The obtained results reveal the practical possibility of applying the fluorescence from dyes as a light source for food system analysis by EEM fluorescence spectroscopy.

Evaluating Radar Reflector Localisation in Targeted Axillary Dissection in Patients Undergoing Neoadjuvant Systemic Therapy for Node-Positive Early Breast Cancer: A Systematic Review and Pooled Analysis.

SAVI SCOUT® or radar reflector localisation (RRL) has proven accurate in localising non-palpable breast and axillary lesions, with minimal interference with MRI. Targeted axillary dissection (TAD), combining marked lymph node biopsy (MLNB) and sentinel lymph node biopsy (SLNB), is becoming a standard post-neoadjuvant systemic therapy (NST) for node-positive early breast cancer. Compared to SLNB alone, TAD reduces the false negative rate (FNR) to below 6%, enabling safer axillary surgery de-escalation. This systematic review evaluates RRL's performance during TAD, assessing localisation and retrieval rates, the concordance between MLNB and SLNB, and the pathological complete response (pCR) in clinically node-positive patients post-NST. Four studies (252 TAD procedures) met the inclusion criteria, with a 99.6% (95% confidence [CI]: 98.9-100) successful localisation rate, 100% retrieval rate, and 81% (95% CI: 76-86) concordance rate between SLNB and MLNB. The average duration from RRL deployment to surgery was 52 days (range:1-202). pCR was observed in 42% (95% CI: 36-48) of cases, with no significant migration or complications reported. Omitting MLNB or SLNB would have under-staged the axilla in 9.7% or 3.4% (p = 0.03) of cases, respectively, underscoring the importance of incorporating MLNB in axillary staging post-NST in initially node-positive patients in line with the updated National Comprehensive Cancer Network (NCCN) guidelines. These findings underscore the excellent efficacy of RRL in TAD for NST-treated patients with positive nodes, aiding in accurate axillary pCR identification and the safe omission of axillary dissection in strong responders.

Extremely Stable Ag-Based Photonics, Plasmonic, Optical, and Electronic Materials and Devices Designed with Surface Chemistry Engineering for Anti-Tarnish.

Silver (Ag) metal-based structures are promising building blocks for next-generation photonics and electronics owing to their unique characteristics, such as high reflectivity, surface plasmonic resonance effects, high electrical conductivity, and tunable electron transport mechanisms. However, Ag structures exhibit poor sustainability in terms of device performance because harsh chemicals, particularly S2- ions present in the air, can damage their structures, lowering their optical and electrical properties. Here, the surface chemistry of Ag structures with (3-mercaptopropyl)trimethoxysilane (MPTS) ligands at room temperature and under ambient conditions is engineered to prevent deterioration of their optical and electrical properties owing to S2- exposure. Regardless of the dimensions of the Ag structures, the MPTS ligands can be applied to each dimension (0D, 1D, and 3D). Consequently, highly sustainable plasmonic effects (Δλ < 2 nm), Fabry-Perot cavity resonance structures (Δλ < 2 nm), reflectors (ΔRReflectance < 0.5%), flexible electrodes (ΔRelectrical < 0.1 Ω), and strain gauge sensors (ΔGF < 1), even in S2- exposing conditions is achieved. This strategy is believed to significantly contribute to environmental pollution reduction by decreasing the volume of electronic waste.

Radar-Guided Localization and Resection for Metastatic Nodal and Soft Tissue Melanoma: A Single-Institution Retrospective Study.

BACKGROUND: Radar-guided localization (RGL) offers a wire-free, nonradioactive surgical guidance method consisting of a small percutaneously-placed radar reflector and handheld probe. This study investigates the feasibility, timing, and outcomes of RGL for melanoma metastasectomy. METHODS: We retrospectively identified patients at our cancer center who underwent RGL resection of metastatic melanoma between December 2020-June 2023. Data pertaining to patients' melanoma history, management, reflector placement and retrieval, and follow-up was extracted from patient charts and analyzed using descriptive statistics. RESULTS: Twenty-three RGL cases were performed in patients with stage III-IV locoregional or oligometastatic disease, 10 of whom had reflectors placed prior to neoadjuvant therapy. Procedures included soft tissue nodule removals (8), index lymph node removals (13), and therapeutic lymph node dissections (2). Reflectors were located and retrieved intraoperatively in 96% of cases from a range of 2 to 282 days after placement; the last reflector was not able to be located during surgery via probe or intraoperative ultrasound. One retrieved reflector had migrated from the index lesion, thus overall success rate of reflector and associated index lesion removal was 21 of 23 (91%). All RGL-localized and retrieved index lesions that contained viable tumor (10) had microscopically negative margins. There were no complications attributable to reflector insertion and no unexpected complications of RGL surgery. CONCLUSION: In our practice, RGL is a safe and effective surgical localization method for soft tissue and nodal melanoma metastases. The inert nature of the reflector enables implantation prior to neoadjuvant therapy with utility in index lymph node removal.

There are a variety of tools available to localize melanoma that had spread to deep layers of the skin or lymph nodes that can guide surgeons to the cancer when the tumor cannot be felt. We evaluated a marker that reflects radar signals that has been studied in breast surgery but not in melanoma. The marker was placed in the tumor before surgery and was located during surgery using a handheld probe, guiding the surgeon to the correct location. An advantage of the radar-reflecting marker we studied is that since it is safe to stay in the body, it can be placed ahead of the use of cancer medications and can keep track of the tumor as it responds to treatment. In a review of 23 surgeries in which the radar-reflecting marker was used, there was one case where the marker migrated away from the tumor and one case where the marker was not able to be located. Monitoring or alternative definitive treatment was provided in each of these cases. Overall, we found the marker to be an effective tumor localization tool for surgeons and safe for patients. Other marker options available are unable or less suitable to be placed a long time in advance of surgery due to either technical or safety reasons, so the radar-reflecting marker is especially useful when it is placed in a tumor ahead of medical treatment leading up to planned surgical treatment.

Use of the lateral arm in tomosynthesis-guided SCOUT Reflector placement procedures.

Preoperative localization procedures are important for guiding surgical excision of non-palpable findings in the breast. The SCOUT Reflector (Merit Medical, South Jordan UT, USA) is a non-wire-based localization device that has been incorporated into clinical use with great success. SCOUT Reflectors can be placed using several imaging modalities, including tomosynthesis. One drawback to SCOUT Reflector placement under tomosynthesis guidance is an inability to directly visualize the introducer needle tip, a factor that limits precision. In this brief communication, we describe the use of a lateral arm attachment for tomosynthesis guided SCOUT Reflector placement. Precise SCOUT Reflector placement can be achieved using the lateral arm due to the ability to clearly visualize the introducer needle and the SCOUT Reflector within the introducer needle bore prior to deployment.

An economic feasibility assessment of implementing photovoltaic module reflectors under Malaysian meteorological conditions.

The use of a reflector can increase the solar radiation on the photovoltaic module (PV) surface, whereby the energy output can be improved. However, the economic feasibility may need to be considered too. This study is conducted, for the first time, due to the lack of studies regarding the economic feasibility assessment of implementing reflectors under the Malaysian meteorological conditions. The outcome will give information about the suitability for implementing a PV reflector in Malaysia through an experimental setup at a sewage treatment site, for two months in 2022. The Malaysian meteorological data, which include daily solar radiation, ambient temperature and wind velocity, were collected to study the output energy, efficiency and the economic perspective of a PV. In February 2022, the PV was operating without a reflector and the averaged values for the monthly solar radiation, ambient temperature and wind velocity were 539.9 MJ/m2, 28.4 °C and 2.2 m/s, respectively, which resulted in an output energy of 106.43 kWh. On the other hand, for April 2022, the PV was operating with a reflector. With the respective averaged input parameters 544.98 MJ/m2, 28.9 °C and 1.51 m/s, the output energy was 121.94 kWh. It is thus shown that the PV with a reflector increases the PV's output energy by 14.57%. Also, it is shown that the cost-effective factor value is 0.955 which means that the PV reflector is economically feasible to be implemented under the Malaysian meteorological conditions. Hence, extensive research should be conducted to improve the performance of PV reflectors. The findings of this paper maybe useful for researchers and/or manufacturers of PV reflectors.

Improvement of Near-Infrared Light-Emitting Diodes' Optical Efficiency Using a Broadband Distributed Bragg Reflector with an AlAs Buffer.

This study developed an advanced 850 nm centered distributed Bragg reflector (DBR) (broadband DBR) composed of nanomaterial-based multiple structures to improve the optical efficiency of an 850 nm near-infrared light-emitting diode (NIR-LED). A combined 850 nm centered broadband DBR was fabricated by growing an 800 nm centered ten-pair DBR on a 900 nm centered ten-pair DBR (denoted as a combined DBR). The combined DBR exhibited a slightly wider peak band than conventional DBRs. Furthermore, the peak band width of the combined DBR significantly increased upon using a reflective AlAs buffer layer that reduced the overlapped reflection. The output power (20.5 mW) of NIR-LED chips using the combined DBR with an AlAs buffer layer exceeded that of a conventional 850 nm centered DBR (14.5 mW) by more than 40%. Results indicated that combining the optical conditions of wavelengths and the AlAs buffer layer effectively strengthened the broadband effect of the DBR and increased the optical efficiency of the 850 nm NIR-LED.

Configuration Investigation, Structure Design and Deployment Dynamics of Rigid-Reflector Spaceborne Antenna with Deviation-Angle Panel.

Rigid-reflector spaceborne antennas (RRSAs) are well-suited for high-frequency application scenarios due to their high surface accuracy. However, the low stowing efficiency of RRSAs limits the aperture diameters and further deteriorates the electromagnetic (EM) performances in terms of gain, resolution and sensitivity. After conducting systematic feature analysis with respect to several typical RRSAs, we propose a novel type of RRSA to solve the aforementioned problems. Inspired by the pose adjustment process for a higher stowing efficiency of traditional RRSAs, we also propose a new segmentation scheme of a reflective surface consisting of a deviation-angle panel that facilitates a higher stowing efficiency. Based on this scheme, its corresponding folded configuration is implemented by combining Euler's rotation theorem and the idea of parameter identification. In addition, we also compare the stowing efficiency of different schemes to verify the high stowing efficiency of the configuration. Finally, we perform mechanism/structure design and deployment dynamics to demonstrate that the antenna can be successfully deployed and exhibits excellent deployment quality. The results suggest that the proposed antenna possesses higher stowing efficiency than that of the same kind, with a stable deployment and interference-free process.

Design of a Deployable Broadband Mesh Reflector Antenna for a SIGINT Satellite System Considering Surface Shape Deformation.

In this paper, we propose a deployable broadband mesh reflector antenna for use in signals intelligence (SIGINT) satellite systems, considering performance degradation due to shape deformation. To maximize gain by increasing the diameter of the reflector while reducing the weight of the antenna, the reflector of the antenna is designed using lightweight silver-coated Teflon mesh. The mesh reflectors are typically expanded by tension to maintain their parabolic structure; thus, shape deformation cannot be avoided. This shape deformation results in shape differences between the surface of the mesh reflector and the ideal parabolic reflector, thus resulting in the degradation of the performance of the mesh reflector antenna. To observe this degradation, we analyze antenna performance according to the number of arms, the number of joints, the feed distance, and the distance from the reflector center to each joint. The performance of the mesh reflector antenna is examined using an effective lossy conducting surface (ELCS) that has the same reflectivity as the silver-coated Teflon mesh to reduce simulation time and computing resources. The designed silver-coated Teflon mesh reflector and the double-ridged feed antenna are fabricated, and the bore-sight gain is measured using the three-antenna method. The measured bore-sight gain of the proposed antenna is 31.6 dBi at 10 GHz, and the measured and simulated results show an average difference of 3.28 dB from 2 GHz to 18 GHz. The proposed deployable mesh reflector antenna can be used in a variety of applications where small stowed volume is required for mobility, such as mobile high-gain antennas as well as satellite antenna systems. Through this study, we demonstrate that shape deformation of the mesh reflector surface significantly affects the performance of reflector antennas.

Efficacy of Targeted Axillary Dissection With Radar Reflector Localization Before Neoadjuvant Chemotherapy.

INTRODUCTION: For clinically node positive breast cancer patients treated with neoadjuvant chemotherapy (NAC), targeted axillary dissection (TAD) can be used to stage the axilla. TAD removes the sentinel lymph node (SLN) and tagged positive nodes, which can be identified via radar reflector localization (RRL). As it can be challenging to localize a previously positive node after NAC, we evaluated RRL prior to NAC. METHODS: We performed a retrospective chart review of breast cancer patients with node positive disease treated with NAC who underwent TAD with RRL. We compared retrieval of radar reflector and clip, timing of localization, and, if a node was positive, whether the radar reflector node or SLN was positive. RESULTS: Seventy-nine patients fulfilled inclusion criteria; 32 were placed pre-NAC (mean 187 d before surgery) and 47 were placed post-NAC (mean 7 d before surgery). For pre-NAC placement, 31 of 32 radar reflectors and 31 of 32 clips were retrieved. For post-NAC placement, 47 of 47 radar reflectors and 46 of 47 clips were retrieved. There was no significant difference in radar reflector or clip retrieval rates between pre-NAC and post-NAC groups (P = 0.41, P = 1, respectively). Thirty of 32 patients with pathologic complete response avoided an axillary lymph node dissection. Of 47 patients with a positive lymph node, 32 were both the SLN and radar reflector node, 11 were radar reflector alone, and four were the SLN. CONCLUSIONS: RRL systems are an effective way to guide TAD, and RRL makers can be safely placed prior to NAC.

Thermal Behavior of Biaxial Piezoelectric MEMS-Scanners.

This paper presents the thermal behavior of non-resonant (quasi-static) piezoelectric biaxial MEMS scanners with Bragg reflectors. These scanners were developed for LIDAR (LIght Detection And Ranging) applications using a pulsed 1550 nm laser with an average power of 2 W. At this power, a standard metal (gold) reflector can overheat and be damaged. The Bragg reflector developed here has up to 24 times lower absorption than gold, which limits heating of the mirror. However, the use of such a reflector involves a technological process completely different from that used for gold and induces, for example, different final stresses on the mirror. In view of the high requirements for optical power, the behavior of this reflector in the event of an increase in temperature needs to be studied and compared with the results of previous studies using gold reflectors. This paper shows that the Bragg reflector remains functional as the temperature rises and undergoes no detrimental deformation even when heated to 200 °C. In addition, the 2D-projection model revealed a 5% variation in optical angle at temperatures up to 150 °C and stability of 2D scanning during one hour of continuous use at 150 °C. The results of this study demonstrate that a biaxial piezoelectric MEMS scanner equipped with Bragg reflector technology can reach a maximum temperature of 150 °C, which is of the same order of magnitude as can be reached by scanners with gold reflectors.

Metamaterial based AMC backed archimedean spiral antenna for in-vitro microwave hyperthermia of skin cancer.

This research article presents a study that uses microwave frequencies (ISM band) for treatment of skin cancer by heating the malignant cells on skin with a Microwave Hyperthermia (MWHT) applicator. The proposed MWHT applicator has been designed as an Archimedean Spiral Microstrip Patch Antenna (AMSPA) of dimensions 38 × 38 × 1.64 mm3 backed with a Meshed-shaped AMC (48 × 48 × 3.27mm3) reflector, placed at an optimized distance of 12 mm from AMSPA. The proposed AMSPA is designed as a single spiral resonator and fabricated on FR-4 substrate, excited using a feed network. The proposed AMSPA shows a resonance at 2.5 GHz with an impedance BW of 260 MHz (2.37-2.63 GHz) and peak gain of 3.20 dB with a bidirectional radiation pattern. An AMC is placed at its backside that can be exploited as a phase-compensation surface to attain an in-phase profile for directive emission and improve the BW upto 470 MHz, peak gain to 6.8 dB and also enhance the front-to-back ratio of the radiating antenna with radiation efficiency of 80%. The simulated environment for hyperthermia analysis is set up using penne's Bio-Heat equations to deliver microwave energy to the bio-mimic, that leads to a rise in temperature over the designed bio-mimic in CST MWS in the range of 41-45°C. The validation of MWHT radiation properties and temperature rise inside the malignancy of phantom is carried out by fabricating the bio-mimic using gelatine, vegetable oils and glycerol. This set up enhances the penetration-depth of EM waves inside the tri-layered phantom up-to 29.5 mm with Effective Field Surface of 36 × 36 mm2 and SAR of 8 W/Kg.

This article discusses the design and development of a device designed to treat skin cancer, specifically melanoma. This device is called a Microwave Hyperthermia (MWHT) applicator. The applicator sends out focused waves of microwave energy but at a specific frequency of ISM band. These waves heat up a model of human skin, simulating what would happen if this is used on a real person with cancer. The goal is to heat the cancer to around 45°C, which can help treat it. The special thing about this applicator is that it's designed to be very compact and have good gain. It heats up the cancer without causing harm to the healthy tissues nearby. The researchers tested it extensively and found that it works well. It has a wide range of effectiveness for different tumor sizes and depths within the skin. To make sure it is safe and accurate, a model of a human forearm using materials like gelatin and water has been prepared. Then used the applicator on this model and measured the temperature increase. After about 40 minutes of exposure, there is a temperature rise of about 45 degrees Celsius. Thus this article is about a device that uses special waves to heat up and treat skin cancer. It's designed to be safe and effective, and the tests show it works on a model of human skin. This could be a useful tool for treating skin cancer in the future.

Anchor Loss Reduction in Micro-Electro Mechanical Systems Flexural Beam Resonators Using Trench Hole Array Reflectors.

The quality factor of microelectromechanical resonators is a crucial performance metric and has thus been the subject of numerous studies aimed at maximizing its value by minimizing the anchor loss. This work presents a study on the effect of elastic wave reflectors on the quality factor of MEMS clamped-clamped flexural beam resonators. The elastic wave reflectors are a series of holes created by trenches in the silicon substrate of the resonators. In this regard, four different shapes of arrayed holes are considered, i.e., two sizes of squares and two half circles with different directions are positioned in proximity to the anchors. The impact of these shapes on the quality factor is examined through both numerical simulations and experimental analysis. A 2D in-plane wave propagation model with a low-reflecting fixed boundary condition was used in the numerical simulation to predict the behavior, and the MEMS resonator prototypes were fabricated using a commercially available micro-fabrication process to validate the findings. Notably, the research identifies that half-circle-shaped holes with their curved sides facing the anchors yield the most promising results. With these reflectors, the quality factor of the resonator is increased by a factor of 1.70× in air or 1.72× in vacuum.