In this study, the utilization of a dry film photoresist (DFR) was explored for fabricating a patterned insulating layer in Ag nanowire (AgNW) bottom electrodes with various designs for flexible ...organic light-emitting diodes (OLEDs). With a single hot-pressing step, a pre-patterned DFR insulator was attached onto the AgNW electrodes, thus forming insulated electrodes in desired patterns. In the same hot-pressing step, AgNWs were also embedded into poly(methyl methacrylate), which sufficiently reduced the root mean square (RMS) roughness (~5 nm) for use in OLED lighting. Using DFR, AgNW electrodes with various shapes were fabricated to realize shaped flexible OLED lighting. The performance of OLED lighting employing the AgNW/patterned-DFR insulator electrode was comparable to that of indium‑tin-oxide-based OLED lighting. Further, the DFR insulator was utilized as a planarization layer in a paper-based OLED lighting, which operated well with a turn-on voltage of 3.5 V and maximum luminance of 157 cd/m2 at 7.5 V.
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•Ag nanowire flexible transparent electrodes with root mean square below 5 nm were fabricated by a single hot pressing process•By using pre-patterned dry film photoresist, shaped Ag nanowire electrodes were fabricated in the same hot pressing process•Flexible organic light-emitting diode lightings with various designs were realized with the fabricated electrodes•Paper-based organic light-emitting diode lighting was realized using a dry film photoresist planarization layer
We report on an all-solution-processed fabrication of highly efficient green quantum dot-light-emitting diodes (QLEDs) with an inverted architecture, where an interfacial polymeric surface modifier ...of polyethylenimine ethoxylated (PEIE) is inserted between a quantum dot (QD) emitting layer (EML) and a hole transport layer (HTL), and a MoO x hole injection layer is solution deposited on top of the HTL. Among the inverted QLEDs with varied PEIE thicknesses, the device with an optimal PEIE thickness of 15.5 nm shows record maximum efficiency values of 65.3 cd/A in current efficiency and 15.6% in external quantum efficiency (EQE). All-solution-processed fabrication of inverted QLED is further implemented on a flexible platform by developing a high-performing transparent conducting composite film of ZnO nanoparticles-overcoated on Ag nanowires. The resulting flexible inverted device possesses 35.1 cd/A in current efficiency and 8.4% in EQE, which are also the highest efficiency values ever reported in flexible QLEDs.
Positioning probe molecules at electromagnetic hot spots with nanometer precision is required to achieve highly sensitive and reproducible surface‐enhanced Raman spectroscopy (SERS) analysis. In this ...article, molecular positioning at plasmonic nanogaps is reported using a high aspect ratio (HAR) plasmonic nanopillar array with a controlled surface energy. A large‐area HAR plasmonic nanopillar array is generated using a nanolithography‐free simple process involving Ar plasma treatment applied to a smooth polymer surface and the subsequent evaporation of metal onto the polymer nanopillars. The surface energy can be precisely controlled through the selective removal of an adsorbed self‐assembled monolayer of low surface‐energy molecules prepared on the plasmonic nanopillars. This process can be used to tune the surface energy and provide a superhydrophobic surface with a water contact angle of 165.8° on the one hand or a hydrophilic surface with a water contact angle of 40.0° on the other. The highly tunable surface wettability is employed to systematically investigate the effects of the surface energy on the capillary‐force‐induced clustering among the HAR plasmonic nanopillars as well as on molecular concentration at the collapsed nanogaps present at the tops of the clustered nanopillars.
Molecular concentration at the electromagnetic hot spots is achieved using surface‐enhanced Raman spectroscopy (SERS) substrates with controlled surface energies. The surface energies of the high aspect ratio plasmonic nanostructures are precisely controlled via the selective removal of low‐surface energy chemicals that is chemisorbed onto the structures.
Sensory neurons generate spike patterns upon receiving external stimuli and encode key information to the spike patterns, enabling energy-efficient external information processing. Herein, we report ...an epifluidic electronic patch with spiking sweat clearance using a sensor containing a vertical sweat-collecting channel for event-driven, energy-efficient, long-term wireless monitoring of epidermal perspiration dynamics. Our sweat sensor contains nanomesh electrodes on its inner wall of the channel and unique sweat-clearing structures. During perspiration, repeated filling and abrupt emptying of the vertical sweat-collecting channel generate electrical spike patterns with the sweat rate and ionic conductivity proportional to the spike frequency and amplitude over a wide dynamic range and long time (> 8 h). With such 'spiking' sweat clearance and corresponding electronic spike patterns, the epifluidic wireless patch successfully decodes epidermal perspiration dynamics in an event-driven manner at different skin locations during exercise, consuming less than 0.6% of the energy required for continuous data transmission. Our patch could integrate various on-skin sensors and emerging edge computing technologies for energy-efficient, intelligent digital healthcare.
Infrared ship-target detection for sea surveillance from the coast is very challenging because of strong background clutter, such as cloud and sea glint. Conventional approaches utilize either ...spatial or temporal information to reduce false positives. This paper proposes a completely different approach, called carbon dioxide-double spike (CO
-DS) detection in midwave spectral imaging. The proposed CO
-DS is based on the spectral feature where a hot CO
emission band is broader than that which is absorbed by normal atmospheric CO
, which generates CO
-double spikes. A directional-mean subtraction filter (D-MSF) detects each CO
spike, and final targets are detected by joint analysis of both types of detection. The most important property of CO
-DS detection is that it generates an extremely low number of false positive caused by background clutter. Only the hot CO
spike of a ship plume can penetrate atmosphere, and furthermore, there are only ship CO
plume signatures in the double spikes of different spectral bands. Experimental results using midwave Fourier transform infrared (FTIR) in a remote sea environment validate the extreme robustness of the proposed ship-target detection.
During road work, lane closures significantly reduce road capacity and negatively impact traffic safety in the upstream segments. This study introduces a merge control strategy for the work zone on ...freeway that aims to alleviate severe congestion and improve flow efficiency in environments where manual vehicles (MVs) and connected automated vehicles (CAVs) coexist. Using a short‐term prediction model combined with a proportional‐integral‐derivative (PID) controller, this strategy dynamically adjusts merging behavior based on real‐time traffic conditions. The PID controller calculates error values as the difference between current and target states, adjusting responses through proportional, integral, and derivative terms. The predictions of the traffic state based on the density of open lanes in each segment guide the controller’s decision to initiate a “Merge” or “No Merge” guidance. When merging is deemed necessary, the controller estimates the optimal number of vehicles to merge for each segment, using the severe congestion threshold as a reference point. This approach was tested using a microscopic simulation tool on a calibrated real‐world network under mixed traffic conditions. The results indicate that the proposed strategy effectively disperses merging upstream, increases merging speeds, and maintains lane density below critical congestion levels, thus enhancing operation efficiency and safety in work zone areas.
This paper presents a novel method for atmospheric transmittance-temperature-emissivity separation (AT2ES) using online midwave infrared hyperspectral images. Conventionally, temperature and ...emissivity separation (TES) is a well-known problem in the remote sensing domain. However, previous approaches use the atmospheric correction process before TES using MODTRAN in the long wave infrared band. Simultaneous online atmospheric transmittance-temperature-emissivity separation starts with approximation of the radiative transfer equation in the upper midwave infrared band. The highest atmospheric band is used to estimate surface temperature, assuming high emissive materials. The lowest atmospheric band (CO2 absorption band) is used to estimate air temperature. Through onsite hyperspectral data regression, atmospheric transmittance is obtained from the y-intercept, and emissivity is separated using the observed radiance, the separated object temperature, the air temperature, and atmospheric transmittance. The advantage with the proposed method is from being the first attempt at simultaneous AT2ES and online separation without any prior knowledge and pre-processing. Midwave Fourier transform infrared (FTIR)-based outdoor experimental results validate the feasibility of the proposed AT2ES method.
Accelerometers are applied to various applications to collect information about movements of other sensors deployed at diverse fields ranging from underwater area to human body. In this study, we try ...to characterize the nonlinear relationship between motion artifact and acceleration data. The cross bicoherence test and the Volterra filter are used as the approaches to detection and modeling. We use the cross bicoherence test to directly detect in the frequency domain and we indirectly identify the nonlinear relationship by improving the performance of eliminating motion artifact in heartbeat rate estimation using a nonlinear filter, the second-order Volterra filter. In the experiments, significant bicoherence values are observed through the cross bicoherence test between the photoplethysmogram (PPG) signal contaminated with motion artifact and the acceleration sensor data. It is observed that for each dataset, the heartbeat rate estimation based on the Volterra filter is superior to that of the linear filter in terms of average absolute error. Furthermore, the leave one out cross-validation (LOOCV) is employed to develop an optimal structure of the Volterra filter for the total datasets. Due to lack of data, the developed Volterra filter does not demonstrate significant difference from the optimal linear filter in terms of t-test. Through this study, it can be concluded that motion artifact may have a quadaratical relationship with acceleration data in terms of bicoherence and more experimental data are required for developing a robust and efficient model for the relationship.
In adult spinal deformity (ASD) surgery, mechanical failure (MF) has been a significant concern for spine surgeons as well as patients. Despite earnest endeavors to prevent MF, the absence of a ...definitive consensus persists, owing to the intricate interplay of multifarious factors associated with this complication. Previous approaches centered around global spinal alignment have yielded limited success in entirely forestalling MF. These methodologies, albeit valuable, exhibited limitations by neglecting to encompass global balance and compensatory mechanisms within their purview. In response to this concern, an in-depth comprehension of global balance and compensatory mechanisms emerges as imperative. In this discourse, the center of gravity and the gravity line are gaining attention in recent investigations pertaining to global balance. This narrative review aims to provide an overview of the global balance and a comprehensive understanding of related concepts and knowledge. Moreover, it delves into the clinical ramifications of the contemporary optimal correction paradigm to furnish an encompassing understanding of global balance and the current optimal correction strategies within the context of ASD surgery. By doing so, it endeavors to furnish spine surgeons with a guiding compass, enriching their decision-making process as they navigate the intricate terrain of ASD surgical interventions.
The Internet-of-Things (IoT) introduces several technical and managerial challenges when it comes to the use of data generated and exchanged by and between various Smart, Connected Products (SCPs) ...that are part of an IoT system (i.e., physical, intelligent devices with sensors and actuators). Added to the volume and the heterogeneous exchange and consumption of data, it is paramount to assure that data quality levels are maintained in every step of the data chain/lifecycle. Otherwise, the system may fail to meet its expected function. While Data Quality (DQ) is a mature field, existing solutions are highly heterogeneous. Therefore, we propose that companies, developers and vendors should align their data quality management mechanisms and artefacts with well-known best practices and standards, as for example, those provided by ISO 8000-61. This standard enables a process-approach to data quality management, overcoming the difficulties of isolated data quality activities. This paper introduces DAQUA-MASS, a methodology based on ISO 8000-61 for data quality management in sensor networks. The methodology consists of four steps according to the Plan-Do-Check-Act cycle by Deming.
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