Conductive Intermediate Layer Research Articles

Oxhide gelatin-regulated aramid nanofiber/liquid metal films with sandwiched structure for electromagnetic interference shielding

Liquid metal (LM) based electromagnetic interference (EMI) shielding materials with high conductivity and continuous deformation capacity are important needs for meeting modern advanced electronic equipment. However, an independent free-standing film with LM is difficult to achieve due to its unique fluidity properties. Here, a simple alternating filtration film-forming method was utilized to orderly construct a sandwiched EMI shielding film with LM stabilized by bio-based oxhide gelatin (gel) as the intermediate conductive layer, and two films of aramid nanofibers/oxhide gel (ANF/gel) as the external insulating protective layers. This design not only prevents LM from being exposed to environmental conditions, but also reduces the risk of chemical corrosion in practical applications. Under optimal LM addition conditions, the sandwiched film (0.3-3 L) exhibited better EMI shielding performance of 50.4 dB in the X-band than the blended film (0.7 dB), as well as excellent mechanical properties (tensile strength of 65.8 MPa, strain 8.6 %). More importantly, the sandwiched film still maintained reliable EMI shielding performance after being experienced largely physical deformation. This study provides a new solution for preparing LM-based EMI shielding composites, and is expected to arouse pursuit of high EMI shielding effects of bio-based gel while also paying attention to their safety.

Flexible Wearable Electronic Fabrics with Dual Functions of Efficient EMI Shielding and Electric Heating for Triboelectric Nanogenerators

Traditional conductive fabrics are prepared by the synthesis of conductive polymers and the coating modification of metals or carbon black conductive materials. However, the conductive fabrics cause a significant decline in performance after washing or mechanical wear, which limits their application. Moreover, the single function of the traditional conductive fabric is also the reason that limits its wide application. In order to prepare a wearable, stable, high-performance, washable, multifunctional conductive fabric, we have carried out related research. In this work, polydopamine was used as a bonding layer, an adsorption reduction layer, and a protective layer to improve the bonding between silver nanoparticles and carbon nanotubes (CNTs) on the polyester fabric surface so as to prepare a multifunctional conductive fabric with a high-stability "sandwich" structure, in which a Ag-NPS@CNT structure acting as an intermediate conductive layer formed on the inner layer PDA@CNT by electroless silver plating and the outermost layer PDA@CNT coated on the surface of the intermediate conductive layer by the impregnation-drying method. The sheet resistance of an E-Fabric can reach 2.11 Ω/□ due to the uniform and dense conductive path formed by the special structure Ag-NPs@CNT. At a low voltage of 1.5 V, the E-Fabric can reach 117 °C in 50 s and remain stable. The electrical conductivity and current heating properties of the E-Fabric remain good even after multiple washing or bending tests. Due to its stable and outstanding electrical conductivity, the E-Fabric has an electromagnetic shielding efficiency (SET) of 35.3 dB in the X-band (8.2-12.4 GHz). In addition, E-Fabric-based spin-coated poly(methyl methacrylate) or polydimethylsiloxane electrodes exhibit excellent performance in nanogenerators. Through the low-frequency friction of the human body, transient voltages up to 4 V can be generated from a 2 cm × 2 cm electrode sample. The output power of a single generator can reach about 12 nW/cm2. Therefore, an E-Fabric is considered to have great potential in the fields of electric heating, electromagnetic shielding, and smart wearable devices.

Design and one-pot direct electrospinning construction of high-performance magnetic@conductive@fluorescent tri-coaxial microbelts and array

Multifunctional materials have more extensive applications than their counterpart single-functional materials due to their superior polyfunctions, among which fluorescent-conductive-magnetic (FCM) multifunctional materials have been extensively investigated for their unique performance and application value. However, the material properties may be degraded due to the adverse interactions among the fluorescent, conductive and magnetic materials with three different functions when they are directly blended. Hence, such adverse interactions brought by the direct contact of different functional materials should be avoided by designing and preparing unique structures. In this study, a one-dimensional (1D) tri-coaxial microbelt is innovatively designed, which can effectively separate and integrate different materials at the micro-level to obtain excellent macroscopic polyfunction. Generally, the preparation of tri-coaxial structure requires multistep procedures. To facilely construct the designed tri-coaxial microbelt, as a case study, a novel [CoFe2O4/polymethyl methacrylate (PMMA)]@[polyaniline (PANI)/PMMA]@[Tb(acac)3bpy/PMMA] (defined as [M@C@F]) tri-coaxial microbelts and arrays are synthesized through the one-pot direct electrospinning (ES) process. The tri-coaxial microbelts are assembled by the CoFe2O4/PMMA magnetic core layer, the PANI/PMMA conductive intermediate layer, and the Tb(acac)3bpy/PMMA insulated-fluorescent shell layer. It is the first time to integrate three different functions into the tri-coaxial microbelts and restrict three functions into three independent zones in the microbelt to shun adverse mutual interferences. The function of each layer can be regulated by adjusting the position and content of the three functional materials. Comparison with the control samples indicates that the property of the tri-coaxial microbelts array is directly impacted by structure and the arrangement modes of the building units. Hence, excellent macroscopic polyfunctions are obtained via designing and preparing microscopic partitioned building units and arranged modes. Array displays superior green fluorescence at 549 nm, tunable electrical conduction and magnetism. The new technique of one-pot direct construction of the tri-coaxial microbelts is significant and can be extended to for assemble other multifunctional materials. Moreover, the constructed [M@C@F] tri-coaxial microbelts and arrays have applications in various fields, such as micro-integrated circuits, microchips, and micro/nanodevices.

Design and finite volume evaluation of a counterflow recuperative spiral heat exchanger for additive manufacturing

There is an ever-increasing demand to find alternatives to carbon based fuel sources and move to renewable electric propulsion systems. Recent advances in additive manufacturing have enabled the manufacturing of complex geometries enabling the potential for higher efficiencies for smaller, more compact designs. The aviation sector is a critical aspect of the transition to electrical population and one that cannot be proactively solved with traditional electric motors. To this end, the use of a superconducting electric motors has been proposed to achieve higher efficiencies and make application within aircraft a viable alternative. The investigation of a cryocooling component, specifically, the ability to pump cryogenic fluid through the electrical systems to maintain the superconducting state is critical to determine the viability of such a design.This paper considers the application of a warm pump in combination with a recuperative heat exchanger to fulfil the cryogenic circulation requirement. The utilisation of additive manufacturing to design complex geometries and ANSYS fluent to verify the effectiveness of the design can result in a superior solution. This paper proposes the use of homogenised heat transfer within the design to achieve both a room temperature output and a cryogenic output. To achieve this, two critical design requirements were proposed; a low thermally conductive intermediate layer to ensure controlled homogenised heat transfer and fixed temperature inlets, one being room temperature and the other at cryogenic temperature. The high temperature gradient across the recuperative heat exchanger, in combination with a low thermally conductive intermediate layer allows for an even heat transfer cumulating in the reversal of the inlet temperatures at an efficiency between 95 and 98 percent.

Performance Enhancement of SnS/h-BN Heterostructure p-Type FET via the Thermodynamically Predicted Surface Oxide Conversion Method.

Searching for the counterpart of well-developed two-dimensional (2D) n-type field effect transistors (FETs) is indispensable for complementary logic circuit applications for 2D devices. Although SnS is regarded as a potential candidate for high-performance p-type FETs, recent experiments only show poor results deviating from the theoretically predicted high mobility. In this research, the serious performance degradation due to the surface oxidation of SnS, which commonly occurs in most 2D materials, is addressed through surface oxide conversion using highly reactive Ti. In this conversion process, which is confirmed by systematic characterization, the reduction of SnS surface oxide is accompanied by the formation of functional titanium oxide, which works as both a conductive intermediate layer to improve the contact property and a buffer layer of the high-k top gate insulator at the channel region. Consequently, a record-high field effect mobility of 87.4 cm2 V-1 s-1 in SnS p-type FETs is achieved. The surface oxide conversion method applied here is consistent with our previous thermodynamic prediction, and this novel technique can be widely introduced to all 2D materials that are vulnerable to oxidation and facilitate the future development of 2D devices.

A Facile and Flexible Humidity Sensor Based on Porous PDMS/AgNWs and GO for Environmental Humidity and Respiratory Detection

AbstractHumidity sensors, benefit from their superior humidity‐sensitive components, are able to respond to the environment moisture changes. Based on this feature, the humidity sensor plays an increasingly vital role in biological detection. To improve the performance of humidity sensors, a large number of optimizations have been made from several aspects, such as material synthesis and structural design. In this study, a novel humidity sensor is designed to increase its specific surface area to carry more humidity‐sensitive and conductive materials. A porous polydimethylsiloxane (PDMS) substrate is prepared in an economical friendly approach by using the thermal decomposition of sodium bicarbonate (NaHCO3). Meanwhile, high‐quality nano silvers (AgNWs) are applied as the intermediate conductive layer connecting the substrate and detective layer. graphene oxide (GO) is used as the humidity sensitive material in the sensor. It is remarkable that this sensor can detect the humidity with a wide range of 8.6 RH% to 93 RH% in a quick response with high sensitivity. Since this humidity sensor showed powerful functions, such as monitoring respiration and detecting environmental humidity, it will have broad potentials for real‐time clinical and domestic healthcare.

Conductive interlayer modulated ferroelectric nanocomposites for high performance triboelectric nanogenerator

Triboelectric nanogenerator (TENG) can convert mechanical energy into electrical energy and has been regarded as a promising portable power source. However, the low output power restricts TENG’s applications in energy harvesters and sensors. Herein, we developed an effective way of increasing TENG’s output power by combining ferroelectricity and conduction of the triboelectric materials. For this purpose, a conductive interlayer modulated ferroelectric nanocomposite was used as the negative triboelectric material. Compared with the conventional ferroelectric nanocomposites based TENG, the transferred triboelectric charge density of the conductive interlayer modulated ferroelectric nanocomposite based TENG can reach 105.70 μC m−2 from 17.50 μC m−2, while the output power density increases to 7.21 W m−2 from 0.11 W m−2. The boosted output performance can be attributed to the existence of a conductive intermediate layer in the negative triboelectric material, which induces charge trapping and enhances ferroelectric polarization of the nanocomposites. Apart from being used as wearable energy harvesters, the TENG device also exhibits a promising application in parachuting surveillance for preventing potential injuries. Furthermore, TENG device has numerous possible application scenarios for future airborne troops. This work provides a brand-new strategy for enhancing contact electrification, showing strong potential in design of high output TENGs.

Fabrication of integrated silicon PIN detector based on Al-Sn-Al bonding for ΔE-E telescope application

The conventional monolithic integration of silicon PIN detector as △E-E telescope suffer from incompatibility with IC process, signal crosstalk, high cost, etc.. In this paper, integrated silicon PIN detector based on Al-Sn-Al bonding is proposed. The intermediate conductive layer between thin and thick PIN structure comprises of metallic bonding layer, which can reduce the signal crosstalk. Moreover, the novel integration process enables known-good-die (KGD) bonding of thin and thick PIN structure, which increases flexibility and reliability of the fabrication process. Besides, the fabrication reduces the cost and increases reliability by utilizing silicon integrated process.

Highly efficient and stable g‑C3N4 decorated Ta3N5 nanotube on n-Si substrate for solar water oxidation

Tantalum nitride (Ta3N5) nanotube (NT) is an up-and-coming visible-light-absorbing photoelectrode material for photoelectrochemical (PEC) solar water oxidation with a small band gap of nearly 2.09 eV and the ability to capture a large fraction of the solar band spectrum up to 600 nm to enhance the PEC performance due to the increased light driving and the total increase of surface region for the high light incorporation and photogenerated charge carrier collection. In here, we deposited Ta metal film onto the n-Si wafer substrate by magnetron sputtering technique and developed a Ta3N5 NT thin-film photoanode with a length of ~1.2 µm by fluorinated-based electrochemical anodization, followed by calcination system in a N2/NH3 mixture gas flow condition. In our experimental results, the film calcined at 700 °C for 7 h showed high visible range of light absorption, well-ordered crystallinity, and a high conductive intermediate layer between the substrate, resulting in an optimized photocurrent density (J) value of ~0.27 mA/cm2 at 1.23 VRHE in photoelectrochemical water oxidation. However, this photoelectrode suffered from a special self-oxidation problem under PEC working conditions. Thus, to improve the photostability and PEC activity of Ta3N5 NT, a thin layer of g-C3N4 with band gap energy of about 2.79 eV was fabricated by an electrophoretic deposition (EPD) method under fixed voltage of (20 V) for 30 sec, 1, 2, 3 and 4 min. The g-C3N4 layer usually possesses several unique properties such as thermal stability, robust deposition process, reasonable band position, and an ability to absorb more visible light region. At an increased the deposition time of 2 min, the g-C3N4 thin layer resolutely coated the surface of Ta3N5 NT and exhibited the maximum J value of ~0.59 mA/cm2 at 1.23 VRHE under solar light irradiation. The modified g-C3N4/Ta3N5NT/Si photoelectrode showed excellent photostability and PEC performance. In the absence of any specific literature report on the preparation and analysis of g-C3N4/Ta3N5NT/Si composites for PEC solar water oxidation, we expect our study to motivate further research to promote the next age generation of g-C3N4/Ta3N5NT-based photoelectrodes with highly efficient PEC cells.

Understanding the Percolation Effect in Triboelectric Nanogenerator with Conductive Intermediate Layer.

Introducing the conductive intermediate layer into a triboelectric nanogenerator (TENG) has been proved as an efficient way to enhance the surface charge density that is attributed to the enhancement of the dielectric permittivity. However, far too little attention has been paid to the companion percolation, another key element to affect the output. Here, the TENG with MXene-embedded polyvinylidene fluoride (PVDF) composite film is fabricated, and the dependence of the output capability on the MXene loading is investigated experimentally and theoretically. Specifically, the surface charge density mainly depends on the dielectric permittivity at lower MXene loadings, and in contrast, the percolation becomes the degrading factor with the further increase of the conductive loadings. At the balance between the dielectric and percolation properties, the surface charge density of the MXene-modified TENG obtained 350% enhancement compared to that with the pure PVDF. This work shed new light on understanding the dielectric and percolation effect in TENG, which renders a universal strategy for the high-performance triboelectronics.

Fiftieth Anniversary of the Kola SG-3 Superdeep Borehole

The results of a comprehensive study of electrical properties of the upper part of the Earth’s crust according to the data of lateral resistivity logging of the Kola SG-3 superdeep borehole and the results of deep and superdeep sounding using controlled sources and electrical profiling on the daylight surface are presented. The possibility of extrapolation of the Kola SG-3 temperature field to a depth below the bottomhole, up to the Moho discontinuity, taking into account the data MHD sounding with the Khibiny source and with the use of industrial power transmission lines (FENICS experiment) is considered. The results of frequency electromagnetic soundings with controlled sources are analyzed, and their geodynamic interpretation is performed together with the data of drilling the SG-3 borehole. The geological and geophysical data are interpreted in the Kola SG-3 section and on the daylight surface to search for homologs and define the nature of the intermediate conductive layer of the dilatancy-diffusion nature (DD layer) discovered in the Earth’s crust of the Baltic Shield at depths from 2–3 to 7–8 km. Based on the latest results of remote deep sounding (the Murman-2018 experiment), it is concluded that, in the vicinity of Kola SG-3 at a depth of 10–12 km, there is a boundary of “impenetrability” for direct current (for the galvanic mode). The geodynamic interpretation of the data is carried out taking into account the model by V.N. Nikolaevskii (1996); it has been suggested that the new boundary most closely corresponds to the brittle-to-quasi-plastic transition area of the Earth’s crust. The results are compared to the log data of the SG-3 borehole and the data of superdeep drilling.

The Kovdor-2015 experiment: study of the parameters of a conductive layer of dilatancy–diffusion nature (DD Layer) in the Archaean crystalline basement of the Baltic Shield

This paper addresses the Kovdor-2015 Experiment involving frequency electromagnetic soundings of the Archaean basement of the Earth’s crust in the southwestern part of the Kola Peninsula. Eleven soundings were carried out using two transmitting arrangements, 85 km apart. Each arrangement consisted of two mutually orthogonal grounded electric dipoles of 1.5 km long. The distances between the source and the receiver were 25 and 50 km. Interpretation of the results took into account the influence of displacement currents and static distortions. It is found that there is an intermediate conductive layer of the dilatancy–diffusion nature (DD layer) with a longitudinal conductivity of about one siemens at depths ranging from 1.5–2 to 5–7 km. The results are interpreted in the terms of geodynamics.

Enhancement of recombination process using silver and graphene quantum dot embedded intermediate layer for efficient organic tandem cells

High performance of organic tandem solar cell is largely dependent on transparent and conductive intermediate layer (IML). The current work reports the design and fabrication of an IML using a simple solution process. The efficiency of a homo-tandem device with poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester as an active layer and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/poly(ethylenimine) as an IML was initially found to be 3.40%. Further enhancement of the cell efficiency was achieved using silver nanoparticles (Ag-NPs) of different sizes and graphene quantum dot embedded IML. A maximum efficiency of 4.03% was achieved using 7 nm Ag-NPs that contribute to a better recombination process. Also, the performance of the tandem cell was solely based on the electrical improvements indicated by the current - voltage measurements, external quantum efficiency and impedance analysis. The use of Ag-NPs in the IML has been shown to lengthen the life time of electron-hole pairs in the device. This study thus paves way to develop such efficient IMLs for more efficient tandem solar cells.

Magnetic properties and microstructure of FePt/MoC/CrRu films

The FePt films with thickness of 4−10nm were deposited on MoC/CrRu/glass at substrate temperature ranged from 260 to 410°C by using magnetron sputtering and strong (001) textured FePt films were obtained at 380°C and 410°C. The multi-functional MoC conductive intermediate layer was used to resist the Cr diffusion and promote the epitaxial growth of the (001) textured FePt film which shows perpendicular magnetization and a linear-like in-plane magnetic loop. The out-of plane coercivity and shape of demagnetization curve were dominated by the ordering degree and perpendicular magnetic anisotropy which were increased with deposited temperature. The FePt film deposited at 290°C shows continuous morphology and change to interconnected structure at 350°C and finally form the island like structure at 380°C and 410°C. Each island contains many FePt grains and the smaller grains size was 12.2nm which obtained at 5nm thick FePt film. Perpendicular anisotropy of 1.1×107erg/cm3 and coercivity of 8.2kOe have been demonstrated in 7nm thick FePt film.

Contribution of multi-method geophysics to the understanding of a high-temperature geothermal province: The Bouillante area (Guadeloupe, Lesser Antilles)

The Bouillante high-temperature geothermal field (Guadeloupe, French Lesser Antilles) is located on the west coast of Basse-Terre Island, about 15km from the currently active Soufrière volcano. We have studied the shallow structure of the geothermal zone using a compilation of all available gravity, magnetic and resistivity data, both subaerial and marine, acquired during the last 30years. Geophysical models have been developed based on geological constraints and previous geophysical interpretations. The resistivity distribution from electromagnetic surveys is interpreted in terms of water saturation of rocks, hydrothermal alteration and presence of hydrated minerals. Gravity is used to distinguish and characterize the denser formations from the low density areas. Finally, we are able to differentiate structures which pre- and post-date various recent magnetic inversions using the polarity of the magnetic anomalies. By integrating these results the previous conceptual model for the geothermal province has been improved, with the layering of the geological formations as defined by geophysical parameters now being taken into account, in agreement with the classical scheme of geothermal reservoirs. The shallow resistive layer is explained in terms of recent massive formations. The conductive intermediate layer marks the low density, demagnetized clay cover of the altered geothermal system. The deep resistive layer is associated with dense formations increasing in age with depth, and corresponds to the deep geothermal reservoir. Based on our geophysical data, the geothermal activity could be more developed towards the east and north compared to the previously proposed area. A volcano-structural control seems to affect the internal structure of the province, and consequently the development of geothermal activity. This current work could be used as a basis for future surveys of the Bouillante province in order to improve constraints, and to increase our knowledge of the island's overall evolution.

MoC intermediate layer for FePt magnetic recording media

A (001) textured FePt film was deposited on MoC/CrRu/glass at a substrate temperature of 380 °C by using magnetron sputtering. The MoC conductive intermediate layer was used to resist the Cr diffusion up to high deposition temperatures and promotes the epitaxial growth of the (001) textured FePt film. The FePt film showed high perpendicular magnetization and the out-of-plane coercivity increased with MoC thickness. The FePt/MoC (5 nm)/CrRu film showed a square out-of-plane magnetic hysteresis loop with a coercivity of 6.0 kOe and a linear-like in-plane loop. A multi-functional MoC intermediate layer exhibited heteroepitaxial relation with FePt and CrRu and was capable of resisting the interlayer diffusion at high deposition temperatures.

Mechanical Stacking Multi Junction Solar Cells Using Transparent Conductive Adhesive

We report a mechanical stacking technology with transparent conductive adhesive as intermediate conductive layer for multi-junction-solar cells. Transparent adhesive jell dispersed with Indium-Tin-Oxide (ITO) particles ranging from 5 to 10 wt% was developed for stacking solar cell substrates. A connecting resistivity below 2.0Ωcm2 was achieved in a condition of solidifying the adhesive gel under a gas pressure from 4.0x105 to 7.0x105 Pa. The connecting resistivity was kept lower than 3.0Ωcm2 when samples was exposed at a high temperature at 80oC and a high humidity of 85% humidity atmosphere in the case of solidification pressure at 7.0x105 Pa. The low connecting resistivity give a possibility of application our conductive adhesive to solar cell with an effective efficiency higher than 30%. Stacked solar cells was successfully achieved by pasting a InGaP/GaAs thin film epitaxial layer to a Ge solar cell using our intermediate adhesive layer.

A passive design strategy for a horizontal ground source heat pump pipe operation optimization with a non-homogeneous soil profile

The effectiveness of a non-homogeneous soil profile for horizontal ground source heat pumps (GSHPs), defined as natural backfill with an intermediate layer of material having different thermal characteristics, is investigated. Steps toward development of a comprehensive model to consider the effects of the non-homogeneous layer are described. The developed model is utilized successfully in conjunction with a genetic algorithm (GA) search method to obtain the optimized operational parameters for a GSHP in three different climate conditions. A properly sized and engineered non-homogeneous soil profile demonstrated the potential to increase the energy extraction/dissipation rates from/to the ground to a significant level. The potential benefit of a recycled product, Tire Derived Aggregate (TDA), as an insulating non-homogeneous layer is assessed. TDA is demonstrated to be more effective in the cold climate (Buffalo) by increasing the energy extraction rates from the ground approximately 15% annually. TDA's effectiveness is less pronounced in a relatively moderate climate (Dallas) by increasing the energy extraction rates from the ground about 4% annually. For the cooling only scenario (Miami), a high conductive intermediate layer of saturated sand exhibited greater potential to increase the energy dissipation to the ground.

Magnetovariational information to improve distortion diagnostics in deep magnetotelluric soundings

An interpretative experience from nine magnetotelluric soundings was accomplished in the central region of Argentina (32°S–34°S; 63°W–69°W), from the Andean region in the west to the platform zone in the east. To do this, magnetovariational information was used to improve the distortion diagnostics in magnetotelluric curves. Using Pilar Geomagnetic Observatory as a reference site, horizontal magnetic transfer functions were estimated, which were compared with the integrate conductivity at each location in field. As a result, a rather simple methodology is proposed to better approach the accurate positions of normal curves. Results suggest that, in this way, better formal interpretations of soundings may be reached. In addition, a more clear and comprehensible knowledge about the nature of lateral in-homogeneities is obtained; e.g., discovering 3-D effects no suspected from tectonic maps. This methodology seems to be particularly useful when-as in the present case-magnetotelluric soundings are far away each others; i.e., when effective volumes of soundings are not interpenetrated. Horizontal magnetovariational information suggests two elongate conductivity anomalies (about N25°–30°E), possibly associated with deep seated faults belonging to the South American regmatic network. These anomalies would be produced by partial melting in lower crust and possibly in the asthenospheric zone next to Andean Range. Another elongate anomaly (possibly of graphitic nature) is shown in the study region. It seems to be a marginal fault following the border between The Sierras Pampeanas dynamic zone and the South American craton. Magnetotelluric results indicate the study region can be considered as divided in a dynamic belt next to Andean Range and a cratonic zone eastward. The dynamic zone presents a well developed lower crust, with conductances ranging 300–4300 Siemens and depths of about 20–30 km. An asthenosphere close to the Andes with 1000 Siemens of conductance at 74 km depth is also observable. Heat flows of 63–70 mW/m2 are estimated next to Andes and 48 mW/m2, eastward, close to South American platform. The cratonic zone presents a first conductive layer with a conductance of 270 Siemens underneath BUL sounding site, but it does not seem to present lateral development. An intermediate conductive layer is also present in this region, but it does not have so much development. Therefore, this layer would not have asthenospheric character; so, the lithosphere would be tied to upper mantle. Heat flows ranging 40–35 mW/m2 were estimated for this cratonic region.

Flank instability structure of Mt. Etna inferred by a magnetotelluric survey

This paper presents a magnetotelluric (MT) survey of the unstable eastern flank of Mt. Etna. We take thirty soundings along two profiles oriented in the N‐S and NW‐SE directions, and from these data recover two 2D resistivity models of the subsurface. Both models reveal three major layers in a resistive‐conductive‐resistive sequence, the deepest extending to 14 km bsl. The shallow layer corresponds to the volcanic cover, and the intermediate conductive layer corresponds to underlying sediments segmented by faults. These two electrical units are cut by ∼ E‐W‐striking faults. The third layer (basement) is interpreted as mainly pertinent to the Apennine‐Maghrebian Chain associated with ∼ SW‐NE‐striking regional faults. The detailed shapes of the resistivity profiles clearly show that the NE Rift is shallow‐rooted (∼0–1 km bsl), thus presumably fed by lateral dikes from the central volcano conduit. The NW‐SE profile suggests by a series of listric faults reaching up to 3 km bsl, then becoming almost horizontal. Toward the SE, the resistive basement dramatically dips (from ∼3 km to ∼10 km bsl), in correspondence with the Timpe Fault System. Several high‐conductivity zones close to the main faults suggest the presence of hydrothermal activity and fluid circulation that could enhance flank instability. Our results provide new findings about the geometry of the unstable Etna flank and its relation to faults and subsurface structures.