There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

In this Progress Report we provide an update on recent developments in inkjet printing technology and its applications, which include organic thin-film transistors, light-emitting diodes, solar cells, conductive structures, memory devices, sensors, and biological/pharmaceutical tasks. Various classes of materials and device types are in turn examined and an opinion is offered about the nature of the progress that has been achieved.

Inkjet Printing—Process and Its Applications

Human skin is a remarkable organ. It consists of an integrated, stretchable network of sensors that relay information about tactile and thermal stimuli to the brain, allowing us to maneuver within our environment safely and effectively. Interest in large-area networks of electronic devices inspired by human skin is motivated by the promise of creating autonomous intelligent robots and biomimetic prosthetics, among other applications. The development of electronic networks comprised of flexible, stretchable, and robust devices that are compatible with large-area implementation and integrated with multiple functionalities is a testament to the progress in developing an electronic skin (e-skin) akin to human skin. E-skins are already capable of providing augmented performance over their organic counterpart, both in superior spatial resolution and thermal sensitivity. They could be further improved through the incorporation of additional functionalities (e.g., chemical and biological sensing) and desired properties (e.g., biodegradability and self-powering). Continued rapid progress in this area is promising for the development of a fully integrated e-skin in the near future.

25th Anniversary Article: The Evolution of Electronic Skin (E-Skin): A Brief History, Design Considerations, and Recent Progress

Fiber-based structures are highly desirable for wearable electronics that are expected to be light-weight, long-lasting, flexible, and conformable Many fibrous structures have been manufactured by well-established lost-effective textile processing technologies, normally at ambient conditions The advancement of nanotechnology has made it feasible to build electronic devices directly on the surface or inside of single fibers, which have typical thickness of several to tens microns However, imparting electronic functions to porous, highly deformable and three-dimensional fiber assemblies and maintaining them during wear represent great challenges from both views of fundamental understanding and practical implementation This article attempts to critically review the current state-of-arts with respect to materials, fabrication techniques, and structural design of devices as well as applications of the fiber-based wearable electronic products In addition, this review elaborates the performance requirements of the fiber-based wearable electronic products, especially regarding the correlation among materials, fiber/textile structures and electronic as well as mechanical functionalities of fiber-based electronic devices Finally, discussions will be presented regarding to limitations of current materials, fabrication techniques, devices concerning manufacturability and performance as well as scientific understanding that must be improved prior to their wide adoption

Fiber‐Based Wearable Electronics: A Review of Materials, Fabrication, Devices, and Applications

An epidermal tattoo sensing platform comprising silver-based electrodes for direct skin physiology monitoring is reported here. The platform uses an assembly of screen-printed elastomeric silver electrodes interfaced with a porous acrylate-based adhesive layer. The elastomeric nature of the electrodes and the inclusion of the porous adhesive layer were demonstrated to improve adhesion strength, lower stiffness and increase fracture strain of the platform. The porous adhesive layer in particular was shown to improve mechanical properties of the platform without impacting on the electrical measurement of viable tissue resistance (Rvt) by the electrodes. Rvt values as measured by the wearable tattoo platform were shown to correlate with tissue dielectric constant (TDC) measurements in a participant study. Topical treatment studies were also carried out whereby single frequency impedance responses of the electrodes was shown to relate to the absorption characteristics of the treatment into the skin. Overall, the work contributes to the area of epidermal sensing and electronics whereby approaches to achieve optimum mechanical properties as well as good electrical fidelity in an epidermal sensor platform are critical to developing wearable sensors for taking robust analytical measurements related to skin physiology.

Robust epidermal tattoo electrode platform for skin physiology monitoring

Enhanced electrochemical reduction of hydrogen peroxide at metallic electrodes modified with surfactant and salt

This work describes the fabrication of gas sensors using inkjet printing. Sensors were constructed by building up a film of sensing material, such as polyaniline, from aqueous nanoparticulate dispersions. These films were printed over patterned silver interdigitated array designs for the purposes of conductimetric analysis. Unlike screen printing or lithography, inkjet printing does not require stencils or masks, therefore allowing rapid design and prototyping. For this study, polyaniline and modified polyaniline sensors were inkjet printed and assessed for the purposes of gas sensing applications, specifically hydrogen sulfide monitoring.

/pdf/fabrication-of-chemical-sensors-using-inkjet-printing-and-2i32f2bhg0.pdf

Fabrication of chemical sensors using inkjet printing and application to gas detection

Electrosynthetic poly(phenol) nanofilms were deposited in situ on platinum elec- trodes in the presence and absence of glucose oxidase. The synthesis charges and currents of the nonconducting polymer films were recorded at various applied potentials for films grown from 25-100 mM phenol concentrations. Film parameters such as the standard rate constant for film deposition, film thickness, and surface concentration of the poly(phenol) films were evaluated from the cyclic and step voltammograms of the polymerization process. A novel electron-transfer mediator consisting of monosubstituted 4-hydroxycyclobut-3-ene-1,2-dione (squarate) was used as a mediator for Pt/poly(phenol) nano-film/GOx amperometric glucose biosensors. Amperometric responses for 3-diphenylamino-4-hydroxycyclobut-3-ene-1,2- dione (diphenylaminosquarate: E°' = of +328 mV/Ag-AgCl at pH 7.0)-mediated systems were measured by both steady-state amperometric and cyclic voltammetry. The sensor sen- sitivity was calculated to be 558 nA cm -2 (µM) -1 .

/pdf/electrochemistry-and-application-of-a-novel-monosubstituted-4p1nmyw1ai.pdf

Electrochemistry and application of a novel monosubstituted squarate electron-transfer mediator in a glucose oxidase-doped poly(phenol) sensor

The engineered addition of hexa-histidine sequences to biomolecules such as antibody fragments has been found to be an excellent means of purifying these materials. This tagging methodology has also been extended to its use as a tool for immobilization and orientation of antibodies on transducer surfaces. Polyvinyl sulfonate-doped polyanilne (PANI/ PVS) can be used as a mediator in amperometric biosensors. This short communication looks at the effect of nickel chelate materials and nickel chelation on this conducting polymer and evaluates it as a potential surface for the immobilization of his-tagged biomolecules. N-nitrilotriacetic acid (NTA) was doped into the electropolymerized PANI/PVS at a screen-printed carbon paste electrode. The resulting NTA-PANI/PVS film was shown to have comparable electrochemical properties of polymer without the chelating agent. When Ni 2þ was applied to the electrode, the incorporated NTA was found to efficiently chelate the metal ions at the electrode surface.

/pdf/development-and-characterization-of-nickel-nta-polyaniline-1v4k3dz1tz.pdf

Aoife Morrin

Papers

Robust epidermal tattoo electrode platform for skin physiology monitoring

Enhanced electrochemical reduction of hydrogen peroxide at metallic electrodes modified with surfactant and salt

Fabrication of chemical sensors using inkjet printing and application to gas detection

Electrochemistry and application of a novel monosubstituted squarate electron-transfer mediator in a glucose oxidase-doped poly(phenol) sensor

Development and Characterization of Nickel-NTA-Polyaniline Modified Electrodes