Flexible Transparent Films of Oriented Silver Nanowires for a Stretchable Strain Sensor.

The potential applications of stretchable strain sensors in wearable electronics have garnered significant attention. However, developing susceptible stretchable strain sensors for practical applications still poses a considerable challenge. The present study introduces a stretchable strain sensor that utilizes silver nanowires (AgNWs) embedded into a polydimethylsiloxane (PDMS) substrate. The AgNWs have high flexibility and electrical conductivity. A stretchable AgNW/Pat-PDMS conductive film was prepared by arranging nanowires on the surface of PDMS using a simple rod coating method. Depending on the orientation angle, the overlap area between nanowires varies, resulting in different levels of separation under a given strain. Due to the separation of the nanowire and the change in current path geometry, the variation in strain resistance of the sensor can be primarily attributed to these factors. Therefore, precision in strain regulation can be adjusted by altering the angle θ (0°, 60°, or 90°) of the nanowire. At the same time, the stability of the AgNW/Pattern-PDMS (AgNW/Pat-PDMS) conductive film application was verified by preparing a sandwich structure PDMS/AgNW/Pat-PDMS stretchable strain sensor. The sensor exhibited high sensitivity within the operating sensing range (gauge factor (GF) of 15 within ~120% strain), superior durability (20,000 bending cycles and 5000 stretching cycles), and excellent response toward bending.

Ultrathin and highly flexible layered silver nanowires/carboxymethyl cellulose nanofiber nanocomposite films for electromagnetic interference shielding.

Lightweight, flexible, efficient and easy-to-manufacture electromagnetic interference (EMI) shielding materials are in urgent demand in the communications industry, artificial intelligence and wearable electronics. Based on the large size difference between one-dimensional carboxymethyl cellulose nanofibers (CMC) and large-diameter silver nanowires (AgNWs), layered AgNWs/CMC nanocomposite films with large effective thickness, and high conductivity were first prepared by a simple one-step vacuum filtration self-assembly technique. The unique layered structure of the AgNWs/CMC nanocomposite film significantly enhances the conductive pathways within the film, endowing it excellent EMI shielding performance. The results show that the conductivity of the ultra-thin film with a thickness of 20 µm is 3.72 × 106 S/m, and the EMI SE in the X-band is 87.7 dB, which can effectively shield electromagnetic signals in mobile communications. Furthermore, the AgNWs/CMCs nanocomposite films exhibit excellent thermal management performance, which can be heated to 100-180 °C within 10 s at a low voltage of 1.5 V. In particular, this nanocomposite film with a new layered structure provides a noval preparation idea for future EMI shielding materials and wearable heating devices.

Ultrasound-Compatible Electrode for Functional Electrical Stimulation.

Functional electrical stimulation (FES) is a vital method in neurorehabilitation used to reanimate paralyzed muscles, enhance the size and strength of atrophied muscles, and reduce spasticity. FES often leads to increased muscle fatigue, necessitating careful monitoring of the patient's response. Ultrasound (US) imaging has been utilized to provide valuable insights into FES-induced fatigue by assessing changes in muscle thickness, stiffness, and strain. Current commercial FES electrodes lack sufficient US transparency, hindering the observation of muscle activity beneath the skin where the electrodes are placed. US-compatible electrodes are essential for accurate imaging and optimal FES performance, especially given the spatial constraints of conventional US probes and the need to monitor muscle areas directly beneath the electrodes. This study introduces specially designed body-conforming US-compatible FES (US-FES) electrodes constructed with a silver nanowire/polydimethylsiloxane (AgNW/PDMS) composite. We compared the performance of our body-conforming US-FES electrode with a commercial hydrogel electrode. The findings revealed that our US-FES electrode exhibited comparable conductivity and performance to the commercial one. Furthermore, US compatibility was investigated through phantom and in vivo tests, showing significant compatibility even during FES, unlike the commercial electrode. The results indicated that US-FES electrodes hold significant promise for the real-time monitoring of muscle activity during FES in clinical rehabilitative applications.

Capillary Force-Induced Graphene Spontaneous Transfer and Encapsulation of Silver Nanowires for Highly-Stable Transparent Electrodes.

Silver nanowires (NWs) (AgNWs) have emerged as the most promising conductive materials in flexible optoelectronic devices owing to their excellent photoelectric properties and mechanical flexibility. It is widely acknowledged that the practical application of AgNW networks faces challenges, such as high surface roughness, poor substrate adhesion, and limited stability. Encapsulating AgNW networks with graphene has been recognized as a viable strategy to tackle these issues. However, conventional methods like self-assembly reduction-oxidation or chemical vapor deposition often yield graphene protective layers with inherent defects. Here, we propose a novel one-step hot-pressing method containing ethanol solution that combines the spontaneous transfer and encapsulation process of rGO films onto the surface of the AgNWs network, enabling the preparation of flexible rGO/AgNWs/PET (reduced graphene oxide/silver NWs/polyethylene terephthalate) electrodes. The composite electrode exhibits outstanding photoelectric properties (T ≈ 88%, R ≈ 6 Ω sq-1) and possesses a smooth surface, primarily attributed to the capillary force generated by ethanol evaporation, ensuring the integrity of the rGO delamination process on the original substrate. The capillary force simultaneously promotes the tight encapsulation of rGO and AgNWs, as well as the welding of the AgNWs junction, thereby enhancing the mechanical stability (20,000 bending cycles and 100 cycles of taping tests), thermal stability (∼30 °C and ∼25% humidity for 150 days), and environmental adaptability (100 days of chemical attack) of the electrode. The electrode's practical feasibility has been validated by its exceptional flexibility and cycle stability (95 and 98% retention after 5000 bending cycles and 12,000 s long-term cycles) in flexible electrochromic devices.

Multi-Scale MXene/Silver Nanowire Composite Foams with Double Conductive Networks for Multifunctional Integration.

With the onset of the 5G era, wearable flexible electronic devices have developed rapidly and gradually entered the daily life of people. However, the vast majority of research focuses on the integration of functions and performance improvement, while ignoring electromagnetic hazards caused by devices. Herein, the 3D double conductive networks are constructed through a repetitive vacuum-assisted dip-coating technique to decorate the 2D MXene and 1D silver nanowires on the melamine foam. Benefiting from the unique porous structure and multi-scale interconnected frame, the resultant composite foam exhibited high electrical conductivity, low density, superb electromagnetic interference shielding (48.32 dB), and Joule heating performance (up to 90.8 °C under 0.8 V). Furthermore, a single-electrode triboelectric nanogenerator (TENG) with powerful energy harvesting capability is assembled by combining the composite foam with an ultra-thin Ecoflex film and a polyvinylidene fluoride film. Simultaneously, the foam-based TENG can also be considered a reliable wearable sensor for monitoring activity patterns in different parts of the human body. The versatility and scalable manufacturing of high-performance composite foams will provide new design ideas for the development of next-generation flexible wearable devices.

Synthesis and Electrochemical Characterization of Nitrate-Doped Polypyrrole/Ag Nanowire Nanorods as Supercapacitors.

Polypyrrole (PPy)-capped silver nanowire (Ag NW) nanomaterials (core-shell rod-shaped Ag NW@PPy) were synthesized using a one-port suspension polymerization technique. The thickness of the PPy layer on the 50 nm thickness/15 µm length Ag NW was effectively controlled to 10, 40, 50, and 60 nm. Thin films cast from one-dimensional conductive Ag NW@PPy formed a three-dimensional (3D) conductive porous network structure and provided excellent electrochemical performance. The 3D Ag NW@PPy network can significantly reduce the internal resistance of the electrode and maintain structural stability. As a result, a high specific capacitance of 625 F/g at a scan rate of 1 mV/s was obtained from the 3D porous Ag NW@PPy composite film. The cycling performance over a long period exceeding 10,000 cycles was also evaluated. We expect that our core-shell-structured Ag NW@PPy composites and their 3D porous structure network films can be applied as electrochemical materials for the design and manufacturing of supercapacitors and other energy storage devices.

Single-Molecule Fluorescence Probes Interactions between Photoactive Protein-Silver Nanowire Conjugate and Monolayer Graphene.

In this work, we apply single-molecule fluorescence microscopy and spectroscopy to probe plasmon-enhanced fluorescence and Förster resonance energy transfer in a nanoscale assemblies. The structure where the interplay between these two processes was present consists of photoactive proteins conjugated with silver nanowires and deposited on a monolayer graphene. By comparing the results of continuous-wave and time-resolved fluorescence microscopy acquired for this structure with those obtained for the reference samples, where proteins were coupled with either a graphene monolayer or silver nanowires, we find clear indications of the interplay between plasmonic enhancement and the energy transfer to graphene. Namely, fluorescence intensities calculated for the structure, where proteins were coupled to graphene only, are less than for the structure playing the central role in this study, containing both silver nanowires and graphene. Conversely, decay times extracted for the latter are shorter compared to a protein-silver nanowire conjugate, pointing towards emergence of the energy transfer. Overall, the results show that monitoring the optical properties of single emitters in a precisely designed hybrid nanostructure provides an elegant way to probe even complex combination of interactions at the nanoscale.

Fully Screen-Printed and Gentle-to-Skin Wet ECG Electrodes with Compact Wireless Readout for Cardiac Diagnosis and Remote Monitoring.

Recent advances in electrocardiogram (ECG) diagnosis and monitoring have triggered a demand for smart and wearable ECG electrodes and readout systems. Here, we report the development of a fully screen-printed gentle-to-skin wet ECG electrode integrated with a scaled-down printed circuit board (PCB) packaged inside a 3D-printed antenna-on-package (AoP). All three components of the wet ECG electrode (i.e., silver nanowire-based conductive part, electrode gel, and adhesive gel) are screen-printed on a flexible plastic substrate and only require 265 times less metal for the conductive part and 176 times less ECG electrode gel than the standard commercial wet ECG electrodes. In addition, our electrically small AoP achieved a maximum read range of 142 m and offers a 4 times larger wireless communication range than the typical commercial chip antenna. The adult volunteers' study results indicated that our system recorded ECG data that correlated well with data from a commercial ECG system and electrodes. Furthermore, in the context of a 12-lead ECG diagnostic system, the fully printed wet ECG electrodes demonstrated a performance similar to that of commercially available wet ECG electrodes while being gentle on the skin. This was confirmed through a blind review method by two cardiology consultants and one family medicine consultant, validating the consistency of the diagnostic information obtained from both electrodes. In conclusion, these findings highlight the potential of fully screen-printed wet ECG electrodes for both monitoring and diagnostic purposes. These electrodes could serve as potential candidates for clinical practice, and the screen-printing method has the capability to facilitate industrial mass production.

GO/AgNW aided sustained release of ciprofloxacin loaded in Starch/PVA nanocomposite mats for wound dressings application.

Compared to conventional bandages, which do not meet all wound care requirements, nanofiber wound dressings could provide a potentially excellent environment for healing. In the present research, nanocomposite membrane based on starch (St) - polyvinyl alcohol (PVA) nanofibers containing ciprofloxacin antibiotic drug loaded on graphene oxide­silver nanowire (GO-AgNWs) hybrid nanoparticles is produced by electrospinning process. Morphological studies showed that the length and diameter of silver nanowires are 21 ± 9.17 µm and 82 ± 10.52 nm, respectively. The contact angle of 57.1° due to the hydrophilic nature of nanofibers, also the swelling degree of 679.51 % and, the water vapor permeability of 2627 ± 56 (g/m2.day) can be expressed as a confirmation of the ability of this wound dressing to manage secretions around the wound. In evaluating the antibacterial activity of these nanocomposite membranes against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria, the most potent antibacterial effect is in the case of nanofibers containing a high percentage of starch and nanoparticles carrying ciprofloxacin; with non-growth halos of 47.58 mm and 22.06 mm was recorded. The release of ciprofloxacin drug in vitro was reported to be 61.69 % during 24 h, and the final release rate was 82.17 %. Despite the biocompatibility and cell viability of 97.74 % and the biodegradability rate of 28.51 %, the StP-GOAgNWCip nanocomposite membrane can be introduced as a suitable candidate for wound dressing.

Surface Embedded Metal Nanowire-Liquid Metal-Elastomer Hybrid Composites for Stretchable Electronics.

Both liquid metal (LM) and metallic filler-based conductive composites are promising stretchable conductors. LM alloys exhibit intrinsically high deformability but present challenges for patterning on polymeric substrates due to high surface tension. On the other hand, conductive composites comprising metallic fillers undergo considerable decrease in electrical conductivity under mechanical deformation. To address the challenges, we present silver nanowire (AgNW)-LM-elastomer hybrid composite films, where AgNWs and LM are embedded below the surface of an elastomeric matrix, using two fabrication approaches, sequential and mixed. We investigate and understand the process-structure-property relationship of the AgNW-LM-elastomer hybrid composites fabricated using two approaches. Different weight ratios of AgNWs and LM particles provide tunable electrical conductivity. The hybrid composites show more stable electromechanical performance than the composites with AgNWs alone. In particular, 1:2.4 (AgNW:LMP w/w) sequential hybrid composite shows electromechanical stability similar to that of the LM-elastomer composite, with a resistance increase of 2.04% at 90% strain. The sequential approach is found to form AgIn2 intermetallic compounds which along with Ga-In bonds, imparts large deformability to the sequential hybrid composite as well as mechanical robustness against scratching, cutting, peeling, and wiping. To demonstrate the application of the hybrid composite for stretchable electronics, a laser patterned stretchable heater on textile and a stretchable circuit including a light-emitting diode are fabricated.

Analysis of the characteristics of silver nanowires (AgNW) random network for transparent heater applications.

Transparent heaters (THs) find widespread application in various indoor and outdoor settings, such as LCD panels and motorcycle helmet visors. Among the materials used for efficient TH performance, the AgNW network stands out due to its high conductivity, substantial transmittance, and minimal solution requirement. Extensive research has been directed towards enhancing AgNW characteristics, focusing on smaller diameters and longer wires. In TH applications, the primary considerations include a rapid response and elevated temperature. Consequently, this research delves into investigating the impact of parameters like diameter, length, and density on random AgNW networks under varying applied voltages. The finite element method is employed for analyzing temperature changes in response to voltage application, particularly in scenarios involving small-scale setups with high-density and high-percolation AgNW networks. The results reveal a significant increase in the thermal transition rate, ranging from 28% to 36%, with varying densities in the random network. Within the same density, the AgNW network with larger diameters and lengths demonstrates the highest temperatures, aligning with previous calculations. Furthermore, a trade-off exists between optical properties in smaller diameters and electrical properties in larger diameters within a relatively narrow temperature range.

Pressurized Back-Junction Doping via Spray-Coating Silver Nanowires Top Electrodes for Efficient Charge Collection in Bifacial Colloidal PbS Quantum Dot Solar Cells.

Colloidal PbS quantum-dot solar cells (QDSCs) have long suffered from inefficient charge collection near the back-junction due to the lack of p-doping strategy, rendering their bifacial photovoltaic applications unsuccessful. Here, we report highly efficient photocarrier collection in bifacial colloidal PbS QDSCs by exploiting spray-coated silver nanowires (AgNWs) top electrodes. During our spray-coating process, pressurized Ag diffusion occurred toward the active layer, which induced effective p-doping and deep-level passivation. By manipulating the spray pressure, optimum AgNWs' stacking morphology enabling an appropriate level of Ag diffusion could be achieved, leading to Jsc over 30 mA/cm2 from the conventional n-i-p structure upon light illumination to the film side. The morphological and electrical behaviors of AgNWs according to the spray pressure are comprehensively explained in relation to the device performance. Finally, 50 bifacial cells were fabricated over 49 cm2 sized glass substrate, demonstrating the large-area processability and functionality of the spray-coated AgNWs with the effective back-junction engineering.

A Generic Strategy to Create Mechanically Interlocked Nanocomposite/Hydrogel Hybrid Electrodes for Epidermal Electronics.

Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human body. As the primary compliant conductors used in these devices, metallic nanostructure/elastomer composites often struggle to form conformal contact with the textured skin. Hybrid electrodes have been consequently developed based on conductive nanocomposite and soft hydrogels to establish seamless skin-device interfaces. However, chemical modifications are typically needed for reliable bonding, which can alter their original properties. To overcome this limitation, this study presents a facile fabrication approach for mechanically interlocked nanocomposite/hydrogel hybrid electrodes. In this physical process, soft microfoams are thermally laminated on silver nanowire nanocomposites as a porous interface, which forms an interpenetrating network with the hydrogel. The microfoam-enabled bonding strategy is generally compatible with various polymers. The resulting interlocked hybrids have a 28-fold improved interfacial toughness compared to directly stacked hybrids. These electrodes achieve firm attachment to the skin and low contact impedance using tissue-adhesive hydrogels. They have been successfully integrated into an epidermal sleeve to distinguish hand gestures by sensing muscle contractions. Interlocked nanocomposite/hydrogel hybrids reported here offer a promising platform to combine the benefits of both materials for epidermal devices and systems.

Self-Assembled Monolayer and Nanoparticles Coenhanced Fragmented Silver Nanowire Network Memristor.

Silver nanowire (AgNW) networks with self-assembled structures and synaptic connectivity have been recently reported for constructing neuromorphic memristors. However, resistive switching at the cross-point junctions of the network is unstable due to locally enhanced Joule heating and the Gibbs-Thomson effect, which poses an obstacle to the integration of threshold switching and memory function in the same AgNW memristor. Here, fragmented AgNW networks combined with Ag nanoparticles (AgNPs) and mercapto self-assembled monolayers (SAMs) are devised to construct memristors with stable threshold switching and memory behavior. In the above design, the planar gaps between NW segments are for resistive switching, the AgNPs act as metal islands in the gaps to reduce threshold voltage (Vth) and holding voltage (Vhold), and the SAMs suppress surface atom diffusion to avoid Oswald ripening of the AgNPs, which improves switching stability. The fragmented NW-NP/SAM memristors not only circumvent the side effects of conventional NW-stacked junctions to provide durable threshold switching at >Vth but also exhibit synaptic characteristics such as long-term potentiation at ultralow voltage (≪Vth). The combination of NW segments, nanoparticles, and SAMs blazes a new trail for integrating artificial neurons and synapses in AgNW network memristors.

Intrinsically Stretchable, Self-Healing, and Large-Scale Epidermal Bioelectrode Arrays for Electrophysiology and Gesture Recognition.

Electrophysiological (EP) signals, referred to as low-level biopotentials driven by active or passive human movements, are of great importance for kinesiology, rehabilitation, and human-machine interaction. To capture high-fidelity EP signals, bioelectrodes should possess high conductivity, high stretchability, and high conformability to skin. While traditional metal bioelectrodes are endowed with stretchability via complex structural designs, they are vulnerable to external or internal inference due to their low fracture strain and large modulus. Here, we report a self-healing elastic composite of silver nanowire (AgNW), graphite nanosheet, and styrene-block-poly(ethylene-ran-butylene)-block-polystyrene, which exhibits high stretchability of ε = 500%, high conductivity of σ = ∼1923 S·cm-1, and low resistance change (ΔR/R0) of 0.14 at ε = 40% while its resistance increases ∼0.8% after a 24 h stretching operation at ε = 50%. We employed the elastic composites for accurate and stable monitoring of electrocardiograph and surface electromyography (sEMG) signals. Further, we demonstrate an all-solution and printable process to obtain a large-scale sEMG bioelectrode array, enabling highly conformal adhesion on skin and high-fidelity gesture recognition.

Solvent Welding-Based Methods Gently and Effectively Enhance the Conductivity of a Silver Nanowire Network.

To enhance the conductivity of a silver nanowire (Ag NW) network, a facile solvent welding method was developed. Soaking a Ag NW network in ethylene glycol (EG) or alcohol for less than 15 min decreased the resistance about 70%. Further combined solvent processing via a plasmonic welding approach decreased the resistance about 85%. This was achieved by simply exposing the EG-soaked Ag NW network to a low-power blue light (60 mW/cm2). Research results suggest that poly(vinylpyrrolidone) (PVP) dissolution by solvent brings nanowires into closer contact, and this reduced gap distance between nanowires enhances the plasmonic welding effect, hence further decreasing resistance. Aside from this dual combination of methods, a triple combination with Joule heating welding induced by applying a current to the Ag NW network decreased the resistance about 96%. Although conductivity was significantly enhanced, our results showed that the melting at Ag NW junctions was relatively negligible, which indicates that the enhancement in conductivity could be attributed to the removal of PVP layers. Moreover, the approaches were quite gentle so any potential damage to Ag NWs or polymer substrates by overheating (e.g., excessive Joule heating) was avoided entirely, making the approaches suitable for application in devices using heat-sensitive materials.

Multifunctional Ti3C2Tx MXene/Silver Nanowire Membranes with Excellent Catalytic, Antifouling, and Antibacterial Properties for Nitrophenol-Containing Water Purification.

The uncontrolled release of nitrophenol and dye pollutants into water systems is an increasingly serious worldwide concern, and thus efficient wastewater treatment technologies are urgently needed. Herein we report a novel two-dimensional (2D) transition metal carbides and/or nitrides (Ti3C2Tx MXene) membrane modified with silver nanowires (AgNWs) by vacuum assisted filtration technology for the ultrafast nitrophenol catalysis and water purification applications. Regular and controllable membrane transport channels were constructed by stacking Ti3C2Tx MXene nanosheets. Furthermore, the intercalation of AgNWs into the Ti3C2Tx MXene interlayer greatly enlarged the interlayer spacing, resulting in more gaps for fast and selective molecular transport. The optimized Ti3C2Tx MXene@AgNWs (M@A) membrane exhibited a water flux up to ∼191.9 L/(m2 h) while maintaining a high bovine serum albumin (BSA) rejection of ∼95.4%. We emphatically used M@A membranes as efficient catalysts for the reduction of 4-nitrophenol (4-NP), and the results indicated that M@A-12% membrane exhibited the greatest catalytic reduction ability, and recycling utilization. M@A-12% membrane also had an antibacterial rate of more than 99% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This work provides a possibility to expand the application of 2D multifunctional M@A membranes in wastewater treatment and pollutant catalytic degradation.

Wearable Capacitive Tactile Sensor Based on Porous Dielectric Composite of Polyurethane and Silver Nanowire.

In recent years, the implementation of wearable and biocompatible tactile sensing elements with sufficient response into healthcare, medical detection, and electronic skin/amputee prosthetics has been an intriguing but challenging quest. Here, we propose a flexible all-polyurethane capacitive tactile sensor that utilizes a salt crystal-templated porous elastomeric framework filling with silver nanowire as the composite dielectric material, sandwiched by a set of polyurethane films covering silver nanowire networks as electrodes. With the aids of these cubic air pores and conducting nanowires, the fabricated capacitive tactile sensor provides pronounced enhancement of both sensor compressibility and effective relative dielectric permittivity across a broad pressure regime (from a few Pa to tens of thousands of Pa). The fabricated silver nanowire-porous polyurethane sensor presents a sensitivity improvement of up to 4-60 times as compared to a flat polyurethane device. An ultrasmall external stimulus as light as 3 mg, equivalent to an applied pressure of ∼0.3 Pa, can also be clearly recognized. Our all-polyurethane capacitive tactile sensor based on a porous dielectric framework hybrid with conducting nanowire reveals versatile potential applications in physiological activity detection, arterial pulse monitoring, and spatial pressure distribution, paving the way for wearable electronics and artificial skin.

Quantitative non-nutritive sucking measurement as a predictor of oral feeding readiness in newborns.

Background and purpose: The purpose of this study is to examine the relationship between the parameters of a silver nanowire-based flexible pressure sensor developed to measure the non-nutritive sucking (NNS) performance and predict the nutritive sucking status in preterm infants. Methods: Preterm infants who were referred for feeding difficulty during the transition period from tubal feeding to oral feeding were enrolled in our study. A flexible pressure sensor was used to measure the non-nutritive sucking parameters of neonates. The evaluator stimulated the infants' lips and tongue with a pacifier integrated with a sucking pressure sensor, to check whether non-nutritive sucking had occurred. When the sucking reflex was induced, it was measured. The infants' sucking characteristics were subdivided into classifications according to the NOMAS criteria and full oral feeding (FOF) status. Quantitative NNS measurement according to the feeding state was compared between groups. Results: When comparing the quantitative NNS measurement by feeding characteristics, the average sucking pressure was significantly higher in infants in the FOF capable group than those in the incomplete FOF group. In addition, the maximum and average sucking pressure was significantly higher in infants with a normal sucking pattern compared to those with a disorganized sucking pattern. The average NNS pressure was divided over the range of 0-3 kPa and the same weight was assigned to each item. When the optimal cut-off value for the sensitivity and specificity of the average NNS pressure to estimate the FOF was set, a pressure of 1.5 kPa yielded the highest sensitivity (84.62%) and specificity (67.65%) on the receiver operating characteristic (ROC) curve. The area under the curve (AUC) was 0.786, and this result was statistically significant. Conclusions: This study presents a quantitative parameter for non-nutritive sucking in preterm infants with the use of a flexible pressure sensor. Results show possible quantitative indicators that can aid in predicting when preterm infants can transition to oral feeding and their prognosis. This will serve as a basis for future research on determining the feeding transition period of newborns with health conditions that affect oral feeding.

Metal-Organic Framework-Modified Silver Nanowire Transparent Film with Enhanced Conductivity and Stability for Efficient Organic Light-Emitting Diodes.

Silver nanowire (AgNW) is recognized as a critical material for developing the next generation of transparent conductive films (TCFs); however, poor stability remains a major issue. Herein, we demonstrate a stable AgNW TCF passivated by a metal-organic framework (MOF) via a facile solution process. The MOF is chemically bonded to the surface of the AgNWs as a chemical inhibitor, which contributes to passivating highly active sites and providing chemical protection, leading to enhanced resistance to corrosive molecules and thereby offering exceptional stability under an ambient atmosphere. Simultaneously, the binding interaction with the MOF anchors silver atoms at the surface of the nanowires, suppressing their diffusion at high temperatures and allowing the AgNW film to maintain excellent conductivity up to 300 °C. Additionally, the hydrogen bonding between the MOF and the substrate, along with the tight connection of the MOF with AgNWs, improves the welding between the nanowires, enhancing the conductivity of the AgNW film at mild conditions while offering good flexibility and adhesion properties. Furthermore, the OLED device integrating the MOF-modified AgNW electrode shows comparable performance to an indium tin oxide-based device, verifying its huge potential for applications in optoelectronic devices.