Response Of Device Research Articles

An Innovative 3D-IDE Design and Adaptive Signal Extraction Algorithm for Efficient Ovarian Cancer Detection.

This work presents a facile, ultrasensitive, and selective chemiresistive biosensor assisted by an adaptive signal extraction algorithm (ASEA) for detecting vimentin, a potential biomarker for ovarian cancer detection. The low-cost device, fabricated on a PCB substrate through sacrificial copper etching, features a 3D-IDE design with interwoven comb-like structures mimicking the natural symmetry of a droplet. An unequal count of positive and negative concentric circle fingers ensures a uniform, higher electric field over the sensor's surface, as verified by COMSOL Multiphysics 3D simulation. This optimal electric field elegantly reflects changes in the IV characteristics, even with minor variations in surface charge density from probe-target interactions. Graphene oxide, functionalized with a heterobifunctional linker, serves as the sensing nanomaterial. A detailed study examines the device's response with interdigitated gaps from 30 to 150 μm. A wider interdigitated gap introduces greater variability in the response across different voltage levels. To address this, the Python-based ASEA meticulously scans the entire voltage range, isolating the segment of the signal that best balances both the intensity and extension for optimal expression. ASEA boosts the limit of detection (LOD) by five times for sensors with gaps of over 100 μm. The biosensor achieves a minimum LOD of 9.45 fg mL-1 and a highest sensitivity of (ΔR/R) 477 ng mL-1 cm2. The biosensor exhibits excellent selectivity, strong resistance to interfering proteins, and commendable stability, showcasing its potential for on-field and point-of-care testing.

High-selectivity NIR amorphous silicon-based plasmonic photodetector at room temperature

This study employed amorphous materials to construct a Near-Infrared (NIR) photodetector, enabling optical sensing over a non-crystalline platform. Utilizing an Au/a-Si Schottky junction with an interfacial oxide layer, the device showcased its capability as a NIR photodetector, effectively operating within a wavelength range of up to 1700 nm. Remarkably, it exhibited significant surface plasmon resonance peaks with high selectivity, a full-width at half-maximum of less than 3°, and a sensitivity of −33.3 dBm, demonstrated at room temperature and zero-biasing conditions. Barrier lowering under biasing further increases the device's responsivity by an order of magnitude, revealing absorption capabilities that exceed the material's intrinsic bandgap limitations. This advancement opens the door to developing highly selective detectors using cost-effective amorphous materials and straightforward design. Additionally, a-Si-based photodetectors contribute to environmental preservation as they do not contain toxic heavy metals, establishing them as one of the most Eco-friendly detection solutions.

Ecofriendly Printed Wood‐Based Honey‐Gated Transistors for Artificial Synapse Emulation

Printed electronics have traditionally used substrates and materials derived from fuel‐based or less abundant and toxic resources, raising environmental concerns. Wood as a substrate reduces processing steps and enables the integration of intelligent functionalities in wooden furniture, offering biodegradability, nontoxicity, and derivation from renewable sources. In this work, sustainably printed transistors using zinc oxide nanoparticles as the active layer and honey electrolyte on wood substrates are demonstrated as a promising approach to reduce the environmental footprint of electronics. Despite the substrate's high roughness, the transistor exhibits excellent performance for screen‐printed devices, with low on‐voltage of 0.32 ± 0.12 V and high Ion/Ioff of (2.4 ± 0.9) × 104. Further analysis of hysteresis in transfer curves under varying scan rates and sweep ranges reveals the device's ability to adjust memory windows and on‐current. Notably, these devices successfully emulate synapses, exhibiting neural facilitation and plasticity, indicating a shift toward sustainable computing. The device's dynamic response to single and successive presynaptic pulses demonstrates its ability to adjust synaptic weight, transition from transient to persistent memory, and pulse width‐, frequency‐, voltage‐, and number‐dependent excitatory postsynaptic currents. The successful emulation of the learning–forgetting–relearning–forgetting process underscores the device's potential for use in sustainable high‐performance neuromorphic systems.

High-responsivity photoelectrochemical ultraviolet photodetector based on SnO2 nanosheets-Ga2O3

Abstract Tin oxide (SnO2) has garnered significant attention for its high spectral selectivity when used as an ultraviolet photodetector. In this study, SnO2 nanosheets (NSs) were synthesized via a hydrothermal method, followed by spin-coating a layer of Ga2O3 thin film to construct a heterojunction photoelectrochemical ultraviolet photodetector (PEC UV PD). Initially, we investigated the effect of precursor composition on the properties of the Ga2O3 thin films. It was observed that the thickness of the films increased with higher precursor concentrations, while the optical bandgap decreased. Based on these findings, we successfully fabricated the SnO2 NSs-Ga2O3 PEC UV PD. Electrochemical analysis revealed that as the precursor concentration used for spin-coating Ga2O3 increased, the device's responsivity and detectivity initially increased and then decreased. After optimization, the device prepared with a 0.2M Ga(NO3)3 solution spin-coated on SnO2 exhibited excellent spectral selectivity (R 265nm/R 420nm ~ 4472), a responsivity of 4.86 mA W-1, and a detectivity of 2.72×109 Jones. This study demonstrates that coating Ga2O3 is an effective approach to constructing high-performance SnO2-based UV PDs.

Simulation and deposition of Tungsten oxide (WO3) films using DC sputtering towards UV photodetector for high responsivity

Tungsten trioxide (WO3) detects UV radiation with great sensitivity while disregarding visible light, and it also has excellent electron mobility, allowing for efficient charge transport and fast response times. This work aims to develop a highly sensitive UV photodetector using WO3 material by optimizing the deposition parameter partial oxygen pressure (PaO2) and annealing the samples at various temperatures to determine the best PaO2 and annealing temperature that results in an improvement in the UV photodetector's sensitivity. The material WO3 was coated on glass substrates using DC magnetron sputtering while altering the PaO2 as 6 × 10−2 Pa, 4 × 10−2 -2 Pa, and 2 × 10−2 Pa, and then each as-deposited sample from varied PaO2 was annealed at temperatures ranging from 100°C to 400°C. When the sample's responses were compared, it was observed that the sample deposited at PaO2 2 × 10−2 Pa and annealed at 400 °C exhibited good photodetection capabilities, as evidenced by several characterization techniques such as SEM, XRD, and IV characterization. The work was subsequently carried out by evaluating the sample deposited at PaO2 2 × 10−2 Pa and annealed at 700 °C, which produced a good result for UV photodetection with the device's responsivity of 1e+4 A/W.

Coral reefs‐like shape AgI/polypyrrole nanocomposite through the intercalation of iodide ions in the network for optoelectronic applications

AbstractA promising optoelectronic device for light sensing in both the UV and Vis regions is fabricated. This device consists of a nanocomposite resembling coral reefs, termed AgI/polypyrrole‐iodide (AgI/Ppy‐I). The resulting nanocomposite exhibits a hierarchical structure wherein larger particles, comprising smaller particles ~45 nm and an optical bandgap measuring 2.4 eV, form a coral reef‐like morphology. The sensitivity estimation of this constructed optoelectronic device relies on evaluating the current density (Jph) values. Under illumination, a remarkable augmentation in current density (Jph = 0.46 mA cm−2) with a promising value compared to the dark condition's 0.12 mA cm−2. The optical characteristics of this nanocomposite make it highly conducive to efficient UV–Vis light sensing. The values of D (detectivity), reflecting the device's sensitivity, are notably high at 4 × 108 and 3.82 × 108 Jones in the UV and Vis regions, correspondingly. The potential of this photodetector is reinforced by the computed R‐values, which denote the device's responsivity. With values of 1.8 and 1.72 mA W−1 across these two optical regions, correspondingly, it showcases the nanocomposite's effectiveness in transforming incident light into electrical current. Moreover, the appeal of this photodetector extends beyond its performance characteristics. Its cost‐effectiveness, eco‐friendliness, straightforward preparation methodology, scalability for mass production, and high stability collectively. The versatility of this material, coupled with its advantageous attributes, opens avenues for its widespread application, catering to the diverse needs of industries and contributing to the accessibility of efficient optoelectronic devices for a broader audience.

Enhancing photo-response performance through ultrathin Al2O3 modification at the p-SnO2:Al/n-GaN heterojunction interface

We report on photoconductive and p-n heterojunction ultraviolet (UV) photodetectors based on p-type Al-doped SnO2 (p-SnO2:Al) thin films. We investigated the structural, optical, and electrical properties of Al-doped SnO2 thin films prepared using sol-gel methods, with our results being strongly supported by first-principles calculations. To achieve a self-powered photodetector device at zero bias, we fabricated p-SnO2:Al thin film on an n-GaN layer to form a p-n heterojunction. The responsivity of the p-n heterojunction UV detector, measured at zero bias, is 0.05 A/W, indicating good rectification properties. In order to improve device performance, a p-n heterojunction with a passivation layer was formed by inserting an ultrathin Al2O3 layer between the n-GaN layer and the p-SnO2:Al layer. With this change, the device's responsivity was 0.44 A/W at 350 nm at zero bias, roughly 10 times better than the detector without the Al2O3 passivation layer. The insertion of an ultrathin Al2O3 layer, which increases the efficiency of carrier separation on the SnO2 side while lowering the rate of carrier recombination at the interface, is responsible for the increased light responsivity performance.

Flexo-Phototronic Boosted Self-Powered Ultraviolet Detection in ZnAl:Layered Double Hydroxide Nanosheets/NiO Heterostructure.

Developing self-powered and flexible optoelectronic sensors with high responsivity and speed is crucial for modern applications, motivating continuous efforts to enhance their performance. Flexo-phototronics is a less-explored but promising technique to elevate the performance of optoelectronics. Therefore, this work addresses the potential of utilizing the flexo-phototronic effect to enhance the performance of a flexible and self-powered ultraviolet photodetector (UV PD) based on ZnAl:LDH (layered double hydroxides) nanosheets (Ns)/NiO heterostructure. The vertically oriented ZnAl:LDH Ns are synthesized via a simple method involving the immersion of a sputtered 10% Al-doped ZnO thin film in deionized water at room ambient conditions. The fabricated PD exhibits an impressive response to 365 nm UV light, with high sensitivity in the order of 103. The device's photocurrent and responsivity are significantly enhanced by the flexo-phototronic effect, attributed to the flexoelectric properties of ZnAl:LDH Ns. Specifically, applying an inhomogeneous tensile strain of 2% boosted the device responsivity by 57.1% and improved its operational speed. Furthermore, a working model revealing the altered energy-band structure is demonstrated to elucidate the flexo-phototronic-induced boost in the photoresponse. The PD also demonstrated a sustainable performance under severe bending cycles, underlining the good flexibility of the device. The results presented in this study demonstrate a self-powered and flexible UV PD and provide a viable approach to augment the performance of optoelectronics through the flexo-phototronic effect.

Optically-reconfigurable integrated optical directed logic computing based on silicon photonics.

Optical directed logic, as a novel logical operation scheme, harmoniously combines the benefits of optical and electrical signals, surpassing traditional electrical and all-optical logic operations in terms of the flexibility and power consumption. Its potential in high-speed optical signal processing and electro-optical computing is immense. However, achieving tunability of the logic function normally relies on external electrical tuning or multiple laser sources, which often results in excessive power consumption and costs. In this work, by utilizing the polarization state of light within the optical directed logic, we demonstrate an optical directed logic device on a silicon-based platform. This single device can realize three different logic operations, which are XNOR, XOR and NAND, by simply changing the input light's polarization state, which comes at a minimal additional power consumption. Moreover, we also significantly enhance the device's response speed through a novel side-integrated metal thermal phase shifter, reducing the response time to 5 µs. Ultimately, we demonstrate logic operations at 60 kbps which maintains a leading standard among the currently reported thermally tuning optical-directed logic (ODL) devices, and successfully integrated polarization division multiplexing technique into ODL devices. This result provides a novel method to realize high-speed optical directed logic with high reconfigurability, which presents significant application prospects in the high-speed optical information processing field.

CVD-Grown Monolayer MoS2 and GaN Thin Film Heterostructure for a Self-Powered and Bidirectional Photodetector with an Extended Active Spectrum.

Photodetector technology has evolved significantly over the years with the emergence of new active materials. However, there remain trade-offs between spectral sensitivity, operating energy, and, more recently, an ability to harbor additional features such as persistent photoconductivity and bidirectional photocurrents for new emerging application areas such as switchable light imaging and filter-less color discrimination. Here, we demonstrate a self-powered bidirectional photodetector based on molybdenum disulfide/gallium nitride (MoS2/GaN) epitaxial heterostructure. This fabricated detector exhibits self-powered functionality and achieves detection in two discrete wavelength bands: ultraviolet and visible. Notably, it attains a peak responsivity of 631 mAW-1 at a bias of 0V. The device's response to illumination at these two wavelengths is governed by distinct mechanisms, activated under applied bias conditions, thereby inducing a reversal in the polarity of the photocurrent. This work underscores the feasibility of self-powered and bidirectional photocurrent detection but also opens new vistas for technological advancements for future optoelectronic, neuromorphic, and sensing applications.

Boosting conversion efficiency by bandgap engineering of ecofriendly antimony trisulfide indoor photovoltaics via a modeling approach

With the exponential growth of the Internet of Things (IoT), indoor photovoltaics (IPVs) have emerged as a pivotal technology for powering low-power devices, drawing heightened interest due to their adaptability to indoor environments. The Photovoltaic Conversion Efficiency (PCE) of IPV cells is critically dependent on their ability to match the indoor spectrum with the device's response characteristics. In this realm, Antimony Trisulfide (Sb2S3), characterized by its wide bandgap and high absorption coefficient, emerges as a promising candidate for low-light applications. Our study focuses on the modeling and numerical analysis of Sb2S3 thin-film IPV cells by wxAMPS software, aiming to refine both the device structure and its photoelectric performance for effective indoor light harvesting. In a strategic shift from conventional CdS materials, we utilized SnO2—known for its high transmissivity, non-toxicity, and wide bandgap—as the electron transport layer (ETL) in Sb2S3 IPV cells. This substitution notably enhanced the short-wave response, elevating the spectral response from 45 % to 80 % at 400 nm. Additionally, we introduced a bandgap-tunable ZnOS buffer layer. This innovation proved instrumental in rectifying the band alignment mismatch between SnO2 and Sb2S3 layer, thereby optimizing interfacial electron transport properties. The integration of the ZnOS buffer layer effectively improved the fill factor from 40.0 % to 64.7 % of the Sb2S3 IPV cell by solving the band mismatch problem. The resulting optimized Sb2S3 IPV cell demonstrated exceptional response characteristics across the full visible spectrum (400–750 nm) and showed notable photoelectric performance under both fluorescent lamps (FLs) and light-emitting diodes (LEDs). Moreover, a detailed analysis was conducted on the performance differences of the device under indoor light sources compared to solar spectrum conditions, along with the underlying mechanisms. Finally, the Sb2S3 IPV cell achieved a peak theoretical efficiency of 46.25 % under cold white FL lighting, a testament to the optimal match between the device structure and this specific emission power spectrum. This modeling research not only underscores the feasibility of employing antimony-based photovoltaic technologies in indoor settings but also offers theoretical guidance for further advancements in this domain.

Metal inserted doping less dielectrically modulated TFET biomarker for SARs-CoV-2 detection

In this paper, a metal strip loaded doping less TFET (MS-DLTFET) biomarker with four cavities is proposed for SARs-CoV-2 detection virus. The results demonstrate that the proposed device offers an improved biomarker performance by introducing the charged plasma concept and the metal strips. The electrical parameters such as electron tunneling rate, drain current (Ids), current ratio (ION/IOFF), threshold voltage (Vth) are evaluated through simulations by immobilized dielectric constant (k) and charge density (ρ) of the bioelements in the nano-gap cavities. In addition, their sensitivity is also calculated with respect to air. The results depict that the proposed device tenders better performance in terms of Ids, ION/IOFF and Vth sensitivity as compared to existing devices. The device's response time under varying k and ρ values are investigated. The non-uniform cavity configurations formed due to steric hindrance effect are studied. It is found that concave configuration offers the best performance compared to other. Furthermore, the cavity size analysis is also performed to optimize the device performance.

Grooving and Absorption on Substrates to Reduce the Bulk Acoustic Wave for Surface Acoustic Wave Micro-Force Sensors.

Improving measurement accuracy is the core issue with surface acoustic wave (SAW) micro-force sensors. An electrode transducer can stimulate not only the SAW but also the bulk acoustic wave (BAW). A portion of the BAW can be picked up by the receiving transducer, leading to an unwanted or spurious signal. This can harm the device's frequency response characteristics, thereby potentially reducing the precision of the micro-force sensor's measurements. This paper examines the influence of anisotropy on wave propagation, and it also performs a phase-matching analysis between interdigital transducers (IDTs) and bulk waves. Two solutions are shown to reduce the influence of BAW for SAW micro sensors, which are arranged with acoustic absorbers at the ends of the substrate and in grooving in the piezoelectric substrate. Three different types of sensors were manufactured, and the test results showed that the sidelobes of the SAW micro-force sensor could be effectively inhibited (3.32 dB), thereby enhancing the sensitivity and performance of sensor detection. The SAW micro-force sensor manufactured using the new process was tested and the following results were obtained: the center frequency was 59.83 MHz, the fractional bandwidth was 1.33%, the range was 0-1000 mN, the linearity was 1.02%, the hysteresis was 0.59%, the repeatability was 1.11%, and the accuracy was 1.34%.

Uncooled Broadband Photodetection via Light Trapping in Conformal PtTe2-Silicon Nanopillar Heterostructures.

Dirac semimetals have demonstrated significant attraction in the field of optoelectronics due to their unique bandgap structure and high carrier mobility. Combining them with classical semiconductor materials to form heterojunctions enables broadband optoelectronic conversion at room temperature. However, the low light absorption of layered Dirac semimetals substantially limits the device's responsivity in the infrared band. Herein, a three-dimensional (3D) heterostructure, composed of silicon nanopillars (SiNPs) and a conformal PtTe2 film, is proposed and demonstrated to enhance the photoresponsivity for uncooled broadband detection. The light trapping effect in the 3D heterostructure efficiently promotes the interaction between light and PtTe2, while also enhancing the light absorption efficiency of silicon, which enables the enhancement of the device responsivity across a broadband spectrum. Experimentally, the PtTe2-SiNPs heterojunction device demonstrates excellent photoelectric conversion behavior across the visible, near-infrared, and long-wave infrared (LWIR) bands, with its responsivity demonstrating an order-of-magnitude improvement compared to the counterparts with planar silicon heterojunctions. Under 11 μm laser irradiation, the noise equivalent power (NEP) can reach 1.76 nW·Hz-1/2 (@1 kHz). These findings offer a strategic approach to the design and fabrication of high-performance broadband photodetectors based on Dirac semimetals.

Ternary organic bulk-heterojunction strategy enables efficient light utilization for perovskite solar cells

Extending the photoresponse into the near-infrared region (NIR) is an urgent research topic in perovskite solar cells. A ternary bulk heterojunction (BHJ) layer composited with PC61BM, D18-Cl and Y6 was deposited onto the perovskite to broaden light absorption. The ternary BHJ layer can absorb low-energy photons in the NIR region (800–920 nm) and generate excitons. Subsequently, these excitons dissociate into free electrons and holes at the donor-acceptor interface, thus extending the device's photo response up to 920 nm. Moreover, due to the good electron transport capabilities of the acceptors Y6 and PC61BM in the BHJ film, the BHJ layer also acts as the electron transport layer in the inverted PSC device. The inverted P–I–N device based on perovskite/BHJ achieved an external quantum efficiency (EQE) up to 30% in the near-infrared range. Compared to control PSCs, the short-circuit current (JSC) increased from 21.64 to 24.35 mA cm−2, resulting in a high PCE of 19.88%. Additionally, the high hydrophobic surface of the ternary layer contributes to the good long-term stability of the device. The results demonstrate that the ternary organic bulk heterojunction is an effective strategy for achieving efficient light utilization in the near-infrared region and enhancing power conversion efficiency in perovskite solar cells.

High sensitivity I-beam shaped polarization related vector curvature sensor with optical intensity modulation

This paper presents an innovative I-beam optical sensor combining Panda-type polarization-maintaining fiber (PMF) and thin-width polarization-maintaining photonic crystal fiber (PM-PCF), crafted using precision machining techniques like tapering and axially offset splicing. The study explores the impact of structural parameters on the device's optical performance using polarization mode coupling theory and assesses its effectiveness in vector curvature sensing, focusing on intensity sensitivity. A novel dual-parameter differential demodulation technique is proposed, achieving accurate bending angle measurements (error < 2°) through wavelength and intensity-curvature sensitivities. The experimental results highlight the device's impressive maximum intensity-curvature response of 9.36 dB/m−1. With notable responsiveness, low cross-talk, and robust polarization stability, this device holds substantial promise in the realms of fiber lasers and optical communications, serving as an ideal polarization-based, mechanically tunable optical device. Furthermore, it introduces innovative concepts and offers technological support for precision instrument measurements and related fields.

An optoelectronic Coupler based on graphene patterns and SU-8 photoresist

PurposeThe purpose of this research is to efficiently separate incident terahertz (THz) waves into distinct transmission and reflection channels by minimizing the absorption ratio. So, the optical systems operating within the THz frequency range can developed. To achieve a multi-band response, four different periodic arrays of graphene patterns are used. These arrays are strategically stacked on both sides of three SU-8 photoresists, serving as dielectric materials. Consequently, each layer exhibits a unique influence on the device's response, and by applying four external bias voltages, the behavior of the device can be precisely controlled and adjusted.Design/methodology/approachA novel optoelectronic device operating in the THz frequency range is introduced, using periodic arrays of graphene patterns and SU-8 photoresist dielectrics. The design of this device is based on meta-surface principles, using both the equivalent circuit model (ECM) and transmission line concept. The output of the device is a THz coupler implemented by analyzing the reflection and transmission channels. The structure is characterized using the ECM and validated through comprehensive full-wave simulations. By representing the electromagnetic phenomenon with passive circuit elements, enabling the calculation of absorption, reflection and transmission through the application of the theory of maximum power transfer.FindingsBased on simulation results and theoretical analysis, the proposed device exhibits sensitivity to gate biasing, enabling efficient reflection and transmission of THz waves. The device achieves reflection and transmission peaks exceeding across the five distinct THz bands 90%, and its behavior can be tuned by external gate biasing. Moreover, the device's sensitivity to variations in geometrical parameters and chemical potentials demonstrates its reliable performance. With its outstanding performance, this high-performance meta-surface emerges as an ideal candidate for fundamental building blocks in larger optical systems, including sensors and detectors, operating within the THz frequency band.Originality/valueThe proposed device covers a significant portion of the THz gap through the provision of five adjustable peaks for reflection and transmission channels. Additionally, the ECM and impedance matching concept offers a simplified and time-efficient approach to designing the meta-surface. Leveraging this approach, the proposed device is effectively represented using passive circuit elements such as inductors, capacitors and resistors, while its performance is validated through the utilization of the finite element method (FEM) as a full-wave simulation tool. This combination of circuit modeling and FEM simulation contributes to the robustness and accuracy of the device's performance evaluation.

Multidimensional detection enabled by twisted black arsenic-phosphorus homojunctions.

A light field carrying multidimensional optical information, including but not limited to polarization, intensity and wavelength, is essential for numerous applications such as environmental monitoring, thermal imaging, medical diagnosis and free-space communications. Simultaneous acquisition of this multidimensional information could provide comprehensive insights for understanding complex environments but remains a challenge. Here we demonstrate a multidimensional optical information detection device based on zero-bias double twisted black arsenic-phosphorus homojunctions, where the photoresponse is dominated by the photothermoelectric effect. By using a bipolar and phase-offset polarization photoresponse, the device operated in the mid-infrared range can simultaneously detect both the polarization angle and incident intensity information through direct measurement of the photocurrents in the double twisted black arsenic-phosphorus homojunctions. The device's responsivity makes it possible to retrieve wavelength information, typically perceived as difficult to obtain. Moreover, the device exhibits an electrically tunable polarization photoresponse, enabling precise distinction of polarization angles under low-intensity light exposure. These demonstrations offer a promising approach for simultaneous detection of multidimensional optical information, indicating potential for diverse photonic applications.

Energy harvester reliability study by Gaidai reliability method

AbstractThis study validates a novel structural reliability method, particularly suitable for high‐dimensional green energy harvesting device dynamic systems, versus a well‐established bivariate statistical method, known to accurately predict two‐dimensional system extreme response contours. Classic reliability methods dealing with time series do not always have an advantage of dealing easily with dynamic system high dimensionality, along with complex cross‐correlations among different system components. Energy harvesters constitute an important part of modern offshore green energy engineering; hence, proper experimental study along with safety and reliability analysis are of practical design and engineering importance. To study the performance of galloping energy harvesters, a series of laboratory wind tunnel tests have been conducted, selecting different wind speeds. This study illustrates the usage of the advocated novel reliability method, by analyzing bivariate statistics of experimental galloping energy harvester's dynamics. The bivariate statistics was extracted from available experimental results, more specifically for the device's voltage‐force dataset. Advantage of the proposed methodology being that relatively short experimental data record may still yield meaningful design results, provided proper statistical methods have been applied. Safety and reliability are important engineering concerns for all kinds of green energy devices. In the case of measured device's structural response, an accurate prediction of system failure or damage probability is possible, as illustrated in this study. Distinctive advantage of advocated novel semi‐analytical reliability methodology being the fact that it can tackle dynamic systems with practically unlimited number of dimensions (or components), along with complex nonlinear cross‐correlations between different system key components.

Efficient noise suppression via controlling the optical cavity in near-infrared organic photoplethysmography sensors

A high-sensitivity organic photodetector (OPD) that operates in the near-infrared region is developed by controlling the optical micro-cavity effects to extend the device's response wavelength. This OPD is successfully applied to photoplethysmography sensors.