Ultrasensitive strain gauges enabled by graphene-stabilized silicone emulsions

Here, an approach is presented to incorporate graphene nanosheets into a silicone rubber matrix via solid stabilization of oil‐in‐water emulsions. These emulsions can be cured into discrete, graphene‐coated silicone balls or continuous, elastomeric films by controlling the degree of coalescence. The electromechanical properties of the resulting composites as a function of interdiffusion time and graphene loading level are characterized. With conductivities approaching 1 S m−1, elongation to break up to 160%, and a gauge factor of ≈20 in the low‐strain linear regime, small strains such as pulse can be accurately measured. At higher strains, the electromechanical response exhibits a robust exponential dependence, allowing accurate readout for higher strain movements such as chest motion and joint bending. The exponential gauge factor is found to be ≈20, independent of loading level and valid up to 80% strain; this consistent performance is due to the emulsion‐templated microstructure of the composites. The robust behavior may facilitate high‐strain sensing in the nonlinear regime using nanocomposites, where relative resistance change values in excess of 107 enable highly accurate bodily motion monitoring

Early Stage Breast Cancer and Its Association with Diet and Exercise-Related Perceptions and Behaviors to Prevent Recurrence

Background The favorable prognosis for early stage breast cancer survivors may be a reason for the minimal research regarding their quality of life. Prior research has observed more long-term weight gain among early stage survivors compared to cancer-free women of a similar age. It would be useful to study survivors’ perceptions and reported behaviors regarding diet and exercise to see if there is a correlation with previous studies. Methods A sample of 700 breast cancer survivors from Ohio and Michigan was randomly selected from the Northwest Ohio affiliate of the Susan G. Komen For the Cure mailing list and sent a survey for completion. Results 389 survivors completed the survey and among Stage 1 (50/197 = 25.4%) and Stage 2 survivors (24/105 = 22.9%), a small proportion had a positive correlation between self-reported dietary behaviors and their perceived benefits of eating fruits and vegetables. Similar correlations were observed between their self-reported exercise behaviors and their perceived benefits of exercise (Stage 1: 36/197 = 18.3%, Stage 2: 18/105 = 17.1%). Conclusions Regardless of stage, a small proportion of survivors’ self-reported dietary and exercise behaviors match their perceived benefits of diet and exercise. Factors such as access, motivation, and lack of co-morbidities among early stage survivors may prevent them from living healthier post-diagnosis. More thorough dietary and clinical measurements will provide greater certainty. Thus, innovative, sustainable programs must be accessible and provide motivation and social support from family, friends, and other survivors to truly improve quality of life

Functional liquid structures by emulsification of graphene and other two-dimensional nanomaterials

Pickering emulsions stabilised with nanomaterials provide routes to a range of functional macroscopic assemblies. We demonstrate the formation and properties of water-in-oil emulsions prepared through liquid-phase exfoliation of graphene. Due to the functional nature of the stabiliser, the emulsions exhibit conductivity due to inter-particle tunnelling. We demonstrate a strain sensing application with a large gauge factor of ~40; the highest reported in a liquid. Our methodology can be applied to other two-dimensional layered materials opening up applications such as energy storage materials, and flexible and printable electronics

Carbon nanofoam supercapacitor electrodes with enhanced performance using a water-transfer process

Carbon nanofoam (CNF) is a highly porous,amorphous carbon nanomaterial that can be produced through the interaction of a high-fluence laser and a carbon-based target material. The morphology and electrical properties of CNF make it an ideal candidate for super-capacitor applications. In this paper, we prepare and characterize CNF supercapacitor electrodes through two different processes, namely, a direct process and a water-transfer process. We elucidate the influence of the production process on the microstructural properties of the CNF, as well as the final electrochemical performance. We show that a change in morphology due to capillary forces doubles the specific capacitance of the wet-transferred CNF electrodes

Surfactant-free liquid-exfoliated copper hydroxide nanocuboids for non-enzymatic electrochemical glucose detection

To facilitate printable sensing solutions particles need to be suspended and stabilised in a liquid medium. Hansen parameters were used to identify that alcohol–water blends are ideal for stabilising colloidal copper hydroxide in dispersion. The suspended material can be further separated in various size fractions with a distinct cuboid geometry which was verified using atomic force microscopy. This facilitates the development of Raman spectroscopic metrics for determining particle sizes. This aspect ratio is related to the anisotropic crystal structure of the bulk crystallites. As the size of the nanocuboids decreases electrochemical sensitivity of the material increases due to an increase in specific surface area. Electrochemical glucose sensitivity was investigated using both cyclic voltammetry and chronoamperometry. The sensitivity is noted to saturate with film thickness. The electrochemical response of 253 mA M−1 cm−2 up to 0.1 mM and 120 mA cm−2 up to 0.6 mM allow for calibration of potential devices. These results indicate suitability for use as a glucose sensor and, due to the surfactant-free, low boiling point solvent approach used to exfoliate the nanocuboids, it is an ideal candidate for printable solutions. The ease of processing will also allow this material to be integrated in composite films for improved functionality in future devices

Supramolecular clustering of the cardiac sodium channel Nav1.5 in HEK293F cells, with and without the auxiliary β3-subunit.

Voltage-gated sodium channels comprise an ion-selective α-subunit and one or more associated β-subunits. The β3-subunit (encoded by the SCN3B gene) is an important physiological regulator of the heart-specific sodium channel, Nav1.5. We have previously shown that when expressed alone in HEK293F cells, the full-length β3-subunit forms trimers in the plasma membrane. We extend this result with biochemical assays and use the proximity ligation assay (PLA) to identify oligomeric β3-subunits, not just at the plasma membrane, but throughout the secretory pathway. We then investigate the corresponding clustering properties of the α-subunit and the effects upon these of the β3-subunits. The oligomeric status of the Nav1.5 α-subunit in vivo, with or without the β3-subunit, has not been previously investigated. Using super-resolution fluorescence imaging, we show that under conditions typically used in electrophysiological studies, the Nav1.5 α-subunit assembles on the plasma membrane of HEK293F cells into spatially localized clusters rather than individual and randomly dispersed molecules. Quantitative analysis indicates that the β3-subunit is not required for this clustering but β3 does significantly change the distribution of cluster sizes and nearest-neighbor distances between Nav1.5 α-subunits. However, when assayed by PLA, the β3-subunit increases the number of PLA-positive signals generated by anti-(Nav1.5 α-subunit) antibodies, mainly at the plasma membrane. Since PLA can be sensitive to the orientation of proteins within a cluster, we suggest that the β3-subunit introduces a significant change in the relative alignment of individual Nav1.5 α-subunits, but the clustering itself depends on other factors. We also show that these structural and higher-order changes induced by the β3-subunit do not alter the degree of electrophysiological gating cooperativity between Nav1.5 α-subunits. Our data provide new insights into the role of the β3-subunit and the supramolecular organization of sodium channels, in an important model cell system that is widely used to study Nav channel behavior.We would like to thank the Gurdon Institute Imaging Facility for use of their microscope and general assistance. This work was supported by a British Heart Foundation grant (PG/14/79/31102) to APJ and CLHH, The Wellcome Trust, award number: 105727/Z/14/Z to CLHH and a Medical Research Council grant (MR/K015591/1) to CLF, RAL, and STFC

Mid-infrared electrochromics enabled by intraband modulation in carbon nanotube networks

Tuneable infrared properties, such as transparency and emissivity, are highly desirable for a range of applications, including thermal windows and emissive cooling. Here, we demonstrate the use of carbon nanotube networks spray-deposited onto an ionic liquid-infused membrane to fabricate devices with electrochromic modulation in the mid-infrared spectrum, facilitating control of emissivity and apparent temperature. Such modulation is enabled by intraband transitions in unsorted single-walled carbon nanotube networks, allowing the use of scalable nanotube inks for printed devices. These devices are optimized by varying film thickness and sheet resistance, demonstrating the emissivity modulation (from ∼0.5 to ∼0.2). These devices and the understanding thereof open the door to selection criteria for infrared electrochromic materials based on the relationship between band structure, electrochemistry, and optothermal properties to enable the development of solution-processable large-area coatings for widespread thermal management applications