Exploring the Elastomer Influence on the Electromechanical Performance of Stretchable Conductors.

Stretchable electronics has received major attention in recent years due to the prospects of integrating electronics onto and into the human body. While many studies investigate how different conductive fillers perform in stretchable composites, the effect of different elastomers on composite performance, and the related fundamental understanding of what is causing the performance differences, is poorly understood. Here, we perform a systematic investigation of the elastomer influence on the electromechanical performance of gold nanowire-based stretchable conductors based on five chemically different elastomers of similar Young's modulus. The choice of elastomer has a huge impact on the electromechanical performance of the conductors under cyclic strain, as some composites perform well, while others fail rapidly at 100% strain cycling. The lack of macroscopic crack formation in the failing composites indicates that the key aspect for good electromechanical performance is not homogeneous films on the macroscale but rather beneficial interactions on the nanoscale. Based on the comprehensive characterization, we propose a failure mechanism related to the mechanical properties of the elastomers. By improving our understanding of elastomer influence on the mechanisms of electrical failure, we can move toward rational material design, which could greatly benefit the field of stretchable electronics.

Stretchable and biodegradable plant-based redox-diffusion batteries.

The redox-diffusion (RD) battery concept introduces an environmentally friendly solution for stretchable batteries in autonomous wearable electronics. By utilising plant-based redox-active biomolecules and cellulose fibers for the electrode scaffold, separator membrane, and current collector, along with a biodegradable elastomer encapsulation, the battery design overcomes the reliance on unsustainable transition metal-based active materials and non-biodegradable elastomers used in existing stretchable batteries. Importantly, it addresses the drawback of limited attainable battery capacity, where increasing the active material loading often leads to thicker and stiffer electrodes with poor mechanical properties. The concept decouples the active material loading from the mechanical structure of the electrode, enabling high mass loadings, while retaining a skin-like young's modulus and stretchability. A stretchable ion-selective membrane facilitates the RD process, allowing two separate redox couples, while preventing crossovers. This results in a high-capacity battery cell that is both electrochemically and mechanically stable, engineered from sustainable plant-based materials. Notably, the battery components are biodegradable at the end of their life, addressing concerns of e-waste and resource depletion.

Particulate matter exposure induces adverse effects on endometrium and fertility via aberrant inflammatory and apoptotic pathways in vitro and in vivo.

This study aimed to evaluate the adverse effects of particulate matter (PM) exposure on endometrial cells and fertility and to identify possible underlying mechanisms. Thirteen women (aged 15-52 years) were included in this study. Enrolled patients underwent laparoscopic surgery at Gangnam Severance Hospital between 1 January and 31 December 2021. For in vivo experiments, 36 female and nine male C57BL/6 mice were randomly divided into control(vehicle), low-dose(10 mg/kg/d), and high-dose exposure groups(20 mg/kg/d). PM was inhaled nasally for four weeks and natural mating was performed. NIST® SRM® 1648a was used for PM exposure. qRT-PCR, western blotting and Masson's trichrome staining were performed. PM treatment in human endometrial stromal cells induced inflammation with significant upregulation of IL-1ß, p-NF-kB, and p-c-Jun compared to those of controls. Additionally, PM treatment significantly increased apoptosis in human endometrial stromal cells by downregulating p-AKT and upregulating p-p53/p53, Cas-3, BAX/Bcl-2, p-AMPK, and p-ERK. After PM treatment, the relative expression of IL-1ß, IL-6, TNF-α, p-NF-κB, p-c-Jun, and p-Nrf2/Nrf2 significantly increased in murine endometrium compared to those of the controls. Expression of apoptotic proteins p53, p27, and Cas-3, was also significantly elevated in murine endometrium of the PM exposure group compared to that of the controls. A significant increase in expression of procollagen Ⅰ, and Masson's trichrome staining scores in the murine endometrium was noted after PM treatment. PM treatment significantly decreased ERα expression. After natural mating, all 3 female mice in the control group gave birth to 25 offspring (mean 8.1), whereas in the low-dose PM treatment group, two of three female mice gave birth to nine offspring (mean 4.5). No pregnant mice or offspring was present in the high-dose PM treatment group. PM exposure induces adverse effects on the endometrium through aberrant activation of inflammatory and apoptotic pathways and is associated with detrimental effects on murine fertility.

Effects of Intrathecal Ketamine on Cerebrospinal Fluid Levels of Brain-Derived Neurotrophic Factor and Mechanical Allodynia in a Rat Model of Mild Traumatic Brain Injury.

BACKGROUND Ketamine, a compelling candidate for neuropathic pain management, has attracted interest for its potential to elevate brain-derived neurotrophic factor (BDNF) levels. We aimed to assess the effects of intrathecally administered ketamine on the cerebrospinal fluid (CSF) levels of BDNF(c-BDNF) and allodynia in a rat model of traumatic brain injury (TBI). MATERIAL AND METHODS Forty-five rats were divided into 3 groups: sham operation (Group S), untreated TBI (Group T), and ketamine-treated TBI (Group K), with 15 rats in each group. Rats were anesthetized, and their skulls were secured in a stereotactic frame before undergoing craniotomy. A controlled cortical impact (CCI) was induced, followed by injection of ketamine (3.41 µg/g) into the CSF in Group K. In Group T, no drug was injected after CCI delivery. On postoperative days (POD) 1, 7, and 14, the 50% mechanical withdrawal threshold (50% MWT) and c-BDNF levels were assessed. RESULTS Groups T and K exhibited a significantly lower 50% MWT than Group S on POD 1(6.6 [5.7, 8.7] g, 10.0 [6.8, 11.6] g, and 18.7 [11.6, 18.7] g, respectively; P<0.001). The c-BDNF levels in Group K were significantly higher than those in Groups S and T on POD 1 (18.9 [16.1, 23.0] pg/ml, 7.3 [6.0, 8.8] pg/ml, and 11.0 [10.6, 12.3] pg/ml, respectively; P=0.006). CONCLUSIONS Intrathecal ketamine administration did not exhibit anti-allodynic effects following mild TBI. c-BDNF level is a promising potential indicator for predicting the expression of allodynia after mild TBI.

Optimization of extraction condition for platycodin D from Platycodon grandiflorum root and verification of its biological activity.

Platycosides, major components of Platycodon grandiflorum (PG) extract, have been implicated in a wide range of biological effects. In particular, platycodin D (PD) is a well-known main bioactive compound of Platycosides. Despite the biological significance of PD, optimization of extract condition for PD from PG root has not been well investigated. Here, we established the optimum extraction condition as ethanol concentration of 0%, temperature of 50°C, and extraction time of 11 h to obtain PD-rich P. grandiflorum extract (PGE) by using response surface methodology (RSM) with Box-Behnken design (BBD). The 5.63 mg/g of PD was extracted from the PG root in optimum condition, and this result was close to the predicted PD content. To analyze the biological activity of PGE related to mucin production, we demonstrated the inhibitory effect of PGE on PMA-induced hyperexpression of MUC5AC as well as ERK activation, a signal mediator of MUC5AC expression. Moreover, we showed that PGE had expectorant activity in mice. These results indicated that PGE had sufficient functions as a potential mucoregulator and expectorant for treating diverse airway diseases. Additionally, we confirmed that PGE had antioxidant activity and inhibited LPS-induced proinflammatory cytokines, TNF-α, and IL-6. Taken together, PGE derived from novel optimizing conditions showed various biological effects, suggesting that PGE could be directly applied to the food industry as food material having therapeutic and preventive potential for human airway diseases.

In Situ Doping of the PEDOT Top Electrode for All-Solution-Processed Semitransparent Organic Solar Cells.

The development of an ideal solution-processable transparent electrode has been a challenge in the field of all-solution-processed semitransparent organic solar cells (ST-OSCs). We present a novel poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) top electrode for all-solution-processed ST-OSCs through in situ doping of PEDOT:PSS. A strongly polarized long perfluoroalkyl (n = 8) chain-anchored sulfonic acid effectively eliminates insulating PSS and spontaneously crystallizes PEDOT at room temperature, leading to outstanding electrical properties and transparency of PEDOT top electrodes. Doped PEDOT-based ST-OSCs yield a high power conversion efficiency of 10.9% while providing an average visible transmittance of 26.0% in the visible range. Moreover, the strong infrared reflectivity of PEDOT enables ST-OSCs to reject 62.6% of the heat emitted by sunlight (76.7% from infrared radiation), outperforming the thermal insulation capability of commercial tint films. This light management approach using PEDOT enables ST-OSCs to simultaneously provide energy generation and energy savings, making it the first discovery toward sustainable energy in buildings.

Tuneable Anisotropic Plasmonics with Shape-Symmetric Conducting Polymer Nanoantennas.

A wide range of nanophotonic applications rely on polarization-dependent plasmonic resonances, which usually requires metallic nanostructures that have anisotropic shape. This work demonstrates polarization-dependent plasmonic resonances instead by breaking symmetry via material permittivity. The study shows that molecular alignment of a conducting polymer can lead to a material with polarization-dependent plasma frequency and corresponding in-plane hyperbolic permittivity region. This result is not expected based only on anisotropic charge mobility but implies that also the effective mass of the charge carriers becomes anisotropic upon polymer alignment. This unique feature is used to demonstrate circularly symmetric nanoantennas that provide different plasmonic resonances parallel and perpendicular to the alignment direction. The nanoantennas are further tuneable via the redox state of the polymer. Importantly, polymer alignment could blueshift the plasma wavelength and resonances by several hundreds of nanometers, forming a novel approach toward reaching the ultimate goal of redox-tunable conducting polymer nanoantennas for visible light.

Electronic Effect on Phenoxide Migration at a Nickel(II) Center Supported by a Tridentate Bis(phosphinophenyl)phosphido Ligand.

A phosphide nickel(II) phenoxide pincer complex (2) reacts with CO(g) to give a pseudo-tetrahedral nickel(0) monocarbonyl complex (3) possessing a phosphinite moiety. This metal-ligand cooperative (MLC) transformation occurs with a (PPP)Ni scaffold (PPP- = P[2-PiPr2-C6H4]2-), which can accommodate both square planar and tetrahedral geometries. The 2-electron reduction of a nickel(II) species induced by CO coordination involves group transfer to generate a P-O bond. For better mechanistic understanding, a series of nickel(II) phenolate complexes (2a-2e, XC6H4O- (X = OMe, Me, H, and CF3) and pentafluorophenolate) were prepared. Kinetic experimental data reveal that a phenolate species with an electron-withdrawing group reacts faster than those with electron-donating groups. The reaction kinetic experiments were conducted in pseudo-first order conditions at room temperature monitored by UV-vis spectroscopy. A pentafluorophenolate nickel(II) complex (2e) reveals instantaneous reactions even at -40 °C to give a nickel(0) monocarbonyl species (3e) and the reverse reaction is also possible. According to kinetic experiments, the rate determining step (RDS) would be the formation of a 5-coordinate intermediate 4 with a negative entropy value (ΔS‡ < 0), and a positive ρ value based on the Hammett plot indicates that the electron-deficient phenolate leads to a faster CO association. Furthermore, scramble experiments suggest that phenolate de-coordinates from the intermediate 4, which gives a (PPP)Ni-CO species 6. The cationic nickel monocarbonyl intermediate can possess a P--Ni(II), P•-Ni(I), or even a P+-Ni(0) character. Such an inner-sphere electron transfer is suggested when a π-acidic ligand such as CO coordinates to a metal ion. Another possible reaction is homolysis of a Ni-O bond to give P--Ni(I) or P•-Ni(0), when a phenoxyl radical is liberated. Considering the P-O bond formation, closed-shell nucleophilic and open-shell radical pathways are suggested. A phenolate pathway reveals a lower energy state for 2e relative to other complexes (2c and 2d), while its radical pathway undergoes via a higher energy state. Therefore, the formation of a P-O bond may occur with the binding of a closed-shell phenolate to the electron-deficient P center.

Ultrasonographic Carotid Artery Flow Measurements as Predictors of Spinal Anesthesia-Induced Hypotension in Elderly Patients: A Prospective Observational Study.

BACKGROUND In elderly patients, spinal anesthesia-induced hypotension (SAH) can be frequently caused by reduced preload and stiff ventricles. The primary purpose of this study was to investigate the ability of ultrasonographic carotid artery flow measurements during the passive leg raise (PLR) test to predict SAH in elderly patients. The correlation between preoperative transthoracic echocardiography (TTE) measurements and SAH was also investigated. MATERIAL AND METHODS The patients aged over 65 years scheduled for elective surgery under spinal anesthesia were recruited. Preoperative TTE was performed in all patients. Corrected carotid flow time and carotid blood flow were measured in the supine, semirecumbent, and PLR positions. Ultrasonographic carotid artery flow and preoperative TTE measurements were compared between patients who developed SAH and those who did not. Receiver operating characteristic (ROC) curve analysis and logistic regression analysis were used to test the association with SAH. RESULTS SAH occurred in 17 of 50 patients. Carotid blood flow in the semirecumbent position and preoperative mitral inflow E velocity could predict SAH, showing an area under the ROC curve of 0.754 (95% CI, 0.612-0.865) and 0.775 (95% CI, 0.634-0.881), respectively. However, according to the multivariate analysis, the independent risk factor for SAH was mitral inflow E velocity (OR 0.918, 95% CI 0.858-0.982, P=0.013). CONCLUSIONS In elderly patients, ultrasonographic carotid artery flow measurements failed to predict the occurrence of SAH. Only preoperative mitral inflow E velocity of TTE was selected as an independent risk factor for SAH.

Trypsin enhances SARS-CoV-2 infection by facilitating viral entry.

Coronaviruses infect cells by cytoplasmic or endosomal membrane fusion, driven by the spike (S) protein, which must be primed by proteolytic cleavage at the S1/S2 furin cleavage site (FCS) and the S2' site by cellular proteases. Exogenous trypsin as a medium additive facilitates isolation and propagation of several coronaviruses in vitro. Here, we show that trypsin enhances severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in cultured cells and that SARS-CoV-2 enters cells via either a non-endosomal or an endosomal fusion pathway, depending on the presence of trypsin. Interestingly, trypsin enabled viral entry at the cell surface and led to more efficient infection than trypsin-independent endosomal entry, suggesting that trypsin production in the target organs may trigger a high level of replication of SARS-CoV-2 and cause severe tissue injury. Extensive syncytium formation and enhanced growth kinetics were observed only in the presence of exogenous trypsin when cell-adapted SARS-CoV-2 strains were tested. During 50 serial passages without the addition of trypsin, a specific R685S mutation occurred in the S1/S2 FCS (681PRRAR685) that was completely conserved but accompanied by several mutations in the S2 fusion subunit in the presence of trypsin. These findings demonstrate that the S1/S2 FCS is essential for proteolytic priming of the S protein and fusion activity for SARS-CoV-2 entry but not for viral replication. Our data can potentially contribute to the improvement of SARS-CoV-2 production for the development of vaccines or antivirals and motivate further investigations into the explicit functions of cell-adaptation-related genetic drift in SARS-CoV-2 pathogenesis.

Elastic conducting polymer composites in thermoelectric modules.

The rapid growth of wearables has created a demand for lightweight, elastic and conformal energy harvesting and storage devices. The conducting polymer poly(3,4-ethylenedioxythiophene) has shown great promise for thermoelectric generators, however, the thick layers of pristine poly(3,4-ethylenedioxythiophene) required for effective energy harvesting are too hard and brittle for seamless integration into wearables. Poly(3,4-ethylenedioxythiophene)-elastomer composites have been developed to improve its mechanical properties, although so far without simultaneously achieving softness, high electrical conductivity, and stretchability. Here we report an aqueously processed poly(3,4-ethylenedioxythiophene)-polyurethane-ionic liquid composite, which combines high conductivity (>140 S cm-1) with superior stretchability (>600%), elasticity, and low Young's modulus (<7 MPa). The outstanding performance of this organic nanocomposite is the result of favorable percolation networks on the nano- and micro-scale and the plasticizing effect of the ionic liquid. The elastic thermoelectric material is implemented in the first reported intrinsically stretchable organic thermoelectric module.

Direct Patterning of Highly Conductive PEDOT:PSS/Ionic Liquid Hydrogel via Microreactive Inkjet Printing.

The gelation of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has gained popularity for its potential applications in three dimensions, while possessing tissue-like mechanical properties, high conductivity, and biocompatibility. However, the fabrication of arbitrary structures, especially via inkjet printing, is challenging because of the inherent gel formation. Here, microreactive inkjet printing (MRIJP) is utilized to pattern various 2D and 3D structures of PEDOT:PSS/IL hydrogel by in-air coalescence of PEDOT:PSS and ionic liquid (IL). By controlling the in-air position and Marangoni-driven encapsulation, single droplets of the PEDOT:PSS/IL hydrogel as small as a diameter of ≈260 µm are fabricated within ≈600 µs. Notably, this MRIJP-based PEDOT:PSS/IL has potential for freeform patterning while maintaining identical performance to those fabricated by the conventional spin-coating method. Through controlled deposition achieved via MRIJP, PEDOT:PSS/IL can be transformed into different 3D structures without the need for molding, potentially leading to substantial progress in next-generation bioelectronics devices.

Influence of PEDOT:PSS crystallinity and composition on electrochemical transistor performance and long-term stability.

Owing to the mixed electron/hole and ion transport in the aqueous environment, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)-based organic electrochemical transistor has been regarded as one of the most promising device platforms for bioelectronics. Nonetheless, there exist very few in-depth studies on how intrinsic channel material properties affect their performance and long-term stability in aqueous environments. Herein, we investigated the correlation among film microstructural crystallinity/composition, device performance, and aqueous stability in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) films. The highly organized anisotropic ordering in crystallized conducting polymer films led to remarkable device characteristics such as large transconductance (∼20 mS), extraordinary volumetric capacitance (113 F·cm-3), and unprecedentedly high [µC*] value (∼490 F·cm-1V-1s-1). Simultaneously, minimized poly(styrenesulfonate) residues in the crystallized film substantially afforded marginal film swelling and robust operational stability even after >20-day water immersion, >2000-time repeated on-off switching, or high-temperature/pressure sterilization. We expect that the present study will contribute to the development of long-term stable implantable bioelectronics for neural recording/stimulation.

Highly Deformable and See-Through Polymer Light-Emitting Diodes with All-Conducting-Polymer Electrodes.

Despite the high expectation of deformable and see-through displays for future ubiquitous society, current light-emitting diodes (LEDs) fail to meet the desired mechanical and optical properties, mainly because of the fragile transparent conducting oxides and opaque metal electrodes. Here, by introducing a highly conductive nanofibrillated conducting polymer (CP) as both deformable transparent anode and cathode, ultraflexible and see-through polymer LEDs (PLEDs) are demonstrated. The CP-based PLEDs exhibit outstanding dual-side light-outcoupling performance with a high optical transmittance of 75% at a wavelength of 550 nm and with an excellent mechanical durability of 9% bending strain. Moreover, the CP-based PLEDs fabricated on 4 µm thick plastic foils with all-solution processing have extremely deformable and foldable light-emitting functionality. This approach is expected to open a new avenue for developing wearable and attachable transparent displays.

CT arthrography visualizes tissue growth of osteochondral defects of the talus after microfracture.

PURPOSE: Little is known about the arthroscopic or radiographic outcomes after arthroscopic microfracture of osteochondral lesions of the talus (OLTs). The purpose of this study was to investigate tissue growth after arthroscopic microfracture of OLTs using computed tomography arthrography (CTA) and to identify the relationship between CTA findings and clinical outcomes. We hypothesized that the morphology of the repaired tissue would be similar to that of normal anatomy and correlate with the clinical outcomes. METHODS: Forty-two ankles treated using arthroscopic microfracture of OLTs between 2009 and 2014 were monitored. CTA was performed post-operatively at 6 months and at 1 and 2 years after surgery. The post-operative thickness of the repaired tissue associated with OLT (grade) and the volume of the subchondral cystic lesions were evaluated using CTA. Clinical outcomes, including the pain visual analog scale (VAS) and American Orthopaedic Foot and Ankle Society (AOFAS) ankle functional scores, were evaluated and correlated with CTA. RESULTS: The proportion of fully grown tissue (grade 3) increased over time; specifically, the rates were 12/40 (33.3%) at 6 months, 11/18 (61.1%) at 1 year, and 8/10 (80%) at 2 years after surgery (p = 0.005). The VAS pain (p < 0.001) and AOFAS scores (p < 0.001) were also improved at the final follow-up; however, they were not associated with repaired tissue thickness as shown by CTA (n.s.). CONCLUSIONS: After microfracture of OLTs, tissue growth in the osteochondral defects was well visualized using CT arthrography and was observed in most cases. However, the CTA findings were not related to the clinical outcomes. LEVEL OF EVIDENCE: IV.

Magnetic Resonance Imaging and Stress Radiography in Chronic Lateral Ankle Instability.

BACKGROUND: Studies regarding magnetic resonance imaging (MRI) findings of the lateral ankle ligaments in chronic lateral ankle instability and their clinical relevance for surgery are lacking. This study classified the lateral ankle ligament MRI findings of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) in chronic lateral ankle instability (CLAI) and correlated these findings with ankle stress radiographs. METHODS: We included 132 ankles with CLAI that underwent ligament reconstructions from 2006 to 2013. The distributions of the ATFL and CFL morphologies were evaluated using the following categories: (1) the amount of thickness: normal/thickened/attenuated/non-visualized, (2) the presence of discontinuity, (3) wavy or irregular contour, and (4) increased signal intensity on T2-weighted images. The relationships between the ligament morphologies and stress radiographs were analyzed. RESULTS: The ATFL was normal in 5 (4%) ankles, thickened in 35 (27%), attenuated in 76 (58%), and non-visualized in 16 (12%), while the CFL was normal in 39 (30%) ankles, thickened in 42 (32%), attenuated in 44 (33%), and non-visualized in 7 (5%). Discontinuity of the ATFL or CFL was observed in 46 (35%) ankles. Wavy or irregular contours were observed in 55 (42%) ATFLs and 37 (28%) CFLs, and signal intensity of both ligaments was increased in 19 (14%) ankles. ATFL ( P < .001) and CFL thickness ( P = .007) correlated with the talar tilt angle. CONCLUSIONS: The MRI findings of CLAI showed several morphologies and specific incidences for each morphology. Attenuated, wavy appearance was the most frequent MRI pattern. Thickness was related to the degree of instability. LEVEL OF EVIDENCE: Level IV, retrospective case series.

First clinical case of canine granulocytic anaplasmosis in Korea and genotypic analyses of Anaplasma phagocytophilum.

A 2-year-old male Jindo dog was presented to a local veterinary clinic for anorexia, lethargy, edema around neck, and vomiting. Based on the clinical history, physical examination, hematology, blood chemistry, serology, and PCR, the dog was diagnosed with canine granulocytic anaplasmosis (CGA). PCR and phylogenetic analyses targeting the 16S rRNA, groEL, and msp2 genes of Anaplasma phagocytophilum revealed that the A. phagocytophilum identified in this study subgrouped into alanine and USA groups according to the groEL and msp2 gene sequences, respectively. To the best of our knowledge, this is the first clinical case of CGA in Korea. In addition, detection of clinical CGA belonging to the alanine group is meaningful because only A. phagocytophilum belonging to the serine group has been reported to develop clinical signs.

Highly Stretchable and Highly Conductive PEDOT:PSS/Ionic Liquid Composite Transparent Electrodes for Solution-Processed Stretchable Electronics.

Stretchable conductive materials have received great attention owing to their potential for realizing next-generation stretchable electronics. However, the simultaneous achievement of excellent mechanical stretchability and high electrical conductivity as well as cost-effective fabrication has been a significant challenge. Here, we report a highly stretchable and highly conducting polymer that was obtained by incorporating an ionic liquid. When 1-ethyl-3-methylimidazolium tetracyanoborate (EMIM TCB) was added to an aqueous conducting polymer solution of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), it was found that EMIM TCB acts not only as a secondary dopant but also as a plasticizer for PEDOT:PSS, resulting in a high conductivity of >1000 S cm-1 with stable performance at tensile strains up to 50% and even up to 180% in combination with the prestrained substrate technique. Consequently, by exploiting the additional benefits of high transparency and solution-processability of PEDOT:PSS, we were able to fabricate a highly stretchable, semitransparent, and wholly solution-processed alternating current electroluminescent device with unimpaired performance at 50% strain by using PEDOT:PSS/EMIM TCB composite films as both bottom and top electrodes.

Controlling Molecular Ordering in Aqueous Conducting Polymers Using Ionic Liquids.

The molecular ordering of aqueous conducting polymers is controlled using a rational method. By introducing various ionic liquids, which have designed electrostatic interactions to PEDOT:PSS solutions, the evolution of the molecular ordering of the PEDOT is manipulated. Consequently, highly ordered nanostructures are achieved with a reduced π-π stacking distance of ≈3.38 Å and, thus, a maximum σdc of ≈2100 S cm-1 .

A tunable Au core-Ag shell nanoparticle tip for tip-enhanced spectroscopy.

A single Au nanoparticle (NP) with a diameter of 5 nm was transferred to the end of a Si-tip through a picking process, and an Ag shell with a controlled thickness was formed on the Au core. By carrying out tip-enhanced Raman scattering (TERS) measurements on biphenyl-4-thiol (BPT) with the Au@Ag NP-tip (overall diameter of 22-60 nm), we confirm that such tips show a plasmonic local-field enhancement which is sufficient for tip-enhanced spectro-microscopy.