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Electrografting of an oligophenylene ethynylene monolayer (OPEH) onto a Mylar®-supported PEDOT : PSS and graphene substrate prior to wet-transfer of a graphene top-electrode has been used to create flexible and transparent large-area Mylar–PEDOT : PSS|OPEH|Graphene molecular junctions. The electrical conductance of the Mylar–PEDOT : PSS|OPEH|Graphene structure was determined by conductive probe atomic force microscopy (c-AFM), sampling various regions across the surfaces of multiple devices. All registered I–V curves (sampling size ∼150 tests) give a sigmoidal response, consistent with through molecule conductance and ruling out the presence of direct electrode contacts or short-circuits. The demonstration of the combined use of Mylar-supported PEDOT : PSS and graphene as alternative electrode materials to conventional metal thin film electrodes in large-area molecular junctions opens avenues to enable flexible and transparent molecular (opto)electronic devices.

Plasmonic lattice nanostructures are of technological interest because of their capacity to manipulate light below the diffraction limit. Here, we present a detailed study of dark and bright modes in the visible and near-infrared energy regime of an inverted plasmonic honeycomb lattice by a combination of Au+ focused ion beam lithography with nanometric resolution, optical and electron spectroscopy, and finite-difference time-domain simulations. The lattice consists of slits carved in a gold thin film, exhibiting hotspots and a set of bright and dark modes. We proposed that some of the dark modes detected by electron energy-loss spectroscopy are caused by antiferroelectric arrangements of the slit polarizations with two times the size of the hexagonal unit cell. The plasmonic resonances take place within the 0.5–2 eV energy range, indicating that they could be suitable for a synergistic coupling with excitons in two-dimensional transition metal dichalcogenides materials or for designing nanoscale sensing platforms based on near-field enhancement over a metallic surface.

Plasmonic lattice nanostructures are of technological interest because of their capacity to manipulate light below the diffraction limit. Here, we present a detailed study of dark and bright modes in the visible and near-infrared energy regime of an inverted plasmonic honeycomb lattice by a combination of Au+ focused ion beam lithography with nanometric resolution, optical and electron spectroscopy, and finite-difference time-domain simulations. The lattice consists of slits carved in a gold thin film, exhibiting hotspots and a set of bright and dark modes. We proposed that some of the dark modes detected by electron energy-loss spectroscopy are caused by antiferroelectric arrangements of the slit polarizations with two times the size of the hexagonal unit cell. The plasmonic resonances take place within the 0.5-2 eV energy range, indicating that they could be suitable for a synergistic coupling with excitons in two-dimensional transition metal dichalcogenides materials or for designing nanoscale sensing platforms based on near-field enhancement over a metallic surface.

The desire to continually reduce the lower limits of semiconductor integrated circuit (IC) fabrication methods continues to inspire interest in unimolecular electronics as a platform technology for the realization of future (opto)electronic devices. However, despite successes in developing methods for the construction and measurement of single-molecule and large-area molecular junctions, exercising control over the precise junction geometry remains a significant challenge. Here, host–guest complexes of the wire-like viologen derivative 1,1′-bis(4-(methylthio)-phenyl)-[4,4′-bipyridine]-1,1′-diium chloride ([1][Cl]2) and cucurbit[7]uril (CB[7]) have been self-assembled in a regular pattern over a gold substrate. Subsequently, ligandless gold nanoparticles (AuNPs) synthesized in situ are deposited over the host–guest array. The agreement between the conductance of individual mono-molecular junctions, appropriately chosen as a function of the AuNP diameter, within this array determined by conductive probe atomic force microscope (c-AFM) and true single-molecule measurements for a closely similar host–guest complex within a scanning tunneling microscope break-junction (STM-BJ) indicates the formation of molecular junctions derived from these host–guest complexes without deleterious intermolecular coupling effects.

This study addresses the complementary metal-oxide-semiconductor-compatible fabrication of vertically stacked Si/SiO2/Si nanopillars (NPs) with embedded Si nanodots (NDs) as key functional elements of a quantum-dot-based, gate-all-around single-electron transistor (SET) operating at room temperature. The main geometrical parameters of the NPs and NDs were deduced from SET device simulations using the nextnano++ program package. The basic concept for single silicon ND formation within a confined oxide volume was deduced from Monte-Carlo simulations of ion-beam mixing and SiO x phase separation. A process flow was developed and experimentally implemented by combining bottom-up (Si ND self-assembly) and top-down (ion-beam mixing, electron-beam lithography, reactive ion etching) technologies, fully satisfying process requirements of future 3D device architectures. The theoretically predicted self-assembly of a single Si ND via phase separation within a confined SiO x disc of <500 nm3 volume was experimentally validated. This work describes in detail the optimization of conditions required for NP/ND formation, such as the oxide thickness, energy and fluence of ion-beam mixing, thermal budget for phase separation and parameters of reactive ion beam etching. Low-temperature plasma oxidation was used to further reduce NP diameter and for gate oxide fabrication whilst preserving the pre-existing NDs. The influence of critical dimension variability on the SET functionality and options to reduce such deviations are discussed. We finally demonstrate the reliable formation of Si quantum dots with diameters of less than 3 nm in the oxide layer of a stacked Si/SiO2/Si NP of 10 nm diameter, with tunnelling distances of about 1 nm between the Si ND and the neighboured Si regions forming drain and source of the SET.

The industrial interest in the patterning of polymeric surfaces at the micro/nanoscale to include new functionalities has considerably increased during the last years. Hierarchical organization of micro/nanometric surface textures yields enhanced functional properties such as hydrophobicity, hydrophilicity, antibacterial activity, and optical or chromatic effects to cite some. While high accuracy methods to pattern hierarchical surfaces at the nanoscale have been developed, only some of them have been applied for high volume manufacturing with limited success, mainly because they rely on the use of expensive machinery and moulds or complicated inserts. Therefore, a method using low cost recyclable tooling and process conditions applicable to high-volume manufacturing is currently missing. In this work, a scalable and low-cost method to replicate hierarchical micro/nanostructured surfaces on plastic films is presented, which can be latter used as inlays for injection moulded parts with standard processing conditions. This method is used to demonstrate the feasibility of replicating three level hierarchical micro/nano textured surfaces using recyclable bio-based polymers (of high relevancy in the current plastic pollution context) achieving replication ratios above 90%, comparing the replication results with those obtained in polypropylene. The presence of the micro/nanotextures substantially increases the contact angle of all the polymers tested, yielding values higher than 90° in all the cases. Also, various mechanical properties of the replicated parts for all the polymers injected are characterized one and thirty days after the samples were manufactured, showing fairly constant values. This highlights the validity of the replicated surfaces, regardless of the biopolymers special crystallization characteristics.

The focused ion beam (FIB) is a powerful tool for fabrication, modification, and characterization of materials down to the nanoscale. Starting with the gallium FIB, which was originally intended for photomask repair in the semiconductor industry, there are now many different types of FIB that are commercially available. These instruments use a range of ion species and are applied broadly in materials science, physics, chemistry, biology, medicine, and even archaeology. The goal of this roadmap is to provide an overview of FIB instrumentation, theory, techniques, and applications. By viewing FIB developments through the lens of various research communities, we aim to identify future pathways for ion source and instrumentation development, as well as emerging applications and opportunities for improved understanding of the complex interplay of ion–solid interactions. We intend to provide a guide for all scientists in the field that identifies common research interest and will support future fruitful interactions connecting tool development, experiment, and theory. While a comprehensive overview of the field is sought, it is not possible to cover all research related to FIB technologies in detail. We give examples of specific projects within the broader context, referencing original works and previous review articles throughout.

In this work, block copolymer lithography and ultralow energy ion implantation are combined to obtain nanovolumes with high concentrations of phosphorus atoms periodically disposed over a macroscopic area in a p-type silicon substrate. The high dose of implanted dopants grants a local amorphization of the silicon substrate. In this condition, phosphorus is activated by solid phase epitaxial regrowth (SPER) of the implanted region with a relatively low temperature thermal treatment preventing diffusion of phosphorus atoms and preserving their spatial localization. Surface morphology of the sample (AFM, SEM), crystallinity of the silicon substrate (UV Raman), and position of the phosphorus atoms (STEM- EDX, ToF-SIMS) are monitored during the process. Electrostatic potential (KPFM) and the conductivity (C-AFM) maps of the sample surface upon dopant activation are compatible with simulated I-V characteristics, suggesting the presence of an array of not ideal but working p-n nanojunctions. The proposed approach paves the way for further investigations on the possibility to modulate the dopant distribution within a silicon substrate at the nanoscale by changing the characteristic dimension of the self-assembled BCP film.

[EN]This study analyzes feasibility of complementary metal–oxide–semiconductor (CMOS)-compatible manufacturing of a hybrid single electron transistor–field effect transistor (SET-FET) circuit. The fundamental element towards an operating SET at room temperature is a vertical nanopillar (NP) with embedded Si nanodot generated by ion-beam irradiation. The integration process from NPs to contacted SETs is validated by structural characterization. Then, the monolithic fabrication of planar FETs integrated with vertical SETs is presented, and its compatibility with standard CMOS technology is demonstrated. The work includes process optimization, pillar integrity validation, electrical characterization and simulations taking into account parasitic effects. The FET fabrication process is adapted to meet the requirements of the pre-fabricated NPs. Overall, this work establishes the groundwork for the realization of a hybrid SET-FET circuit operating at room temperature.

We present a fabrication process for the production of 3-dimensional micro-structured polymeric films. The microstructures are fabricated in a single step using thermal nanoimprint lithography as patterning technique. The micro-structured polymer films are then transformed into a 3D shape by means of a plug-assisted thermoforming process, while keeping the functionality of the micro-patterned areas. The preserved functionality is characterized by water contact angle measurements, while the deformation of the micro-structured topographies due to the thermoforming process is analyzed using confocal microscopy and Digital Image Correlation (DIC) techniques. This combined fabrication process represents a promising solution to complement in-mold decoration approaches, enabling the production of new functional surfaces. As the microstructures are fabricated by means of a mechanical modification of the surface, without the need of chemical treatments or coatings, the presented technique represents a promising, simple and green solution, suitable for the industrial fabrication of 3D nonplanar shaped functional surfaces.

Methods for forming single- and multiple-molecule junctions are key to the development of molecular electronics and the further study of allied electronic and electrical properties of molecules arising from through-molecule charge transport. The organometallic complex trans-Ru(C[triple bond, length as m-dash]C-3-C4H3S)(C[triple bond, length as m-dash]C-1,4-C6H4C[triple bond, length as m-dash]CAuPPh3)(dppe)2 forms well-ordered, densely packed self-assembled monolayers on gold and silver substrates, contacted through the sulfur atoms of the thiophenyl groups. Upon mild thermal treatment (150–200 °C, two hours) the gold moiety decomposes to liberate PPh3 and form quite uniform, disc-shaped gold nanoparticles on top of the organometallic monolayer. The resulting molecular junctions give rise to sigmoidal shaped I–V curves characteristic of through-molecule conductance, rather than linear, ohmic traces associated with metallic contacts (i.e. short circuits). This work therefore demonstrates the feasibility of thermal processing routes to form good quality molecular junctions from organometallic complexes of relatively complex molecular structure capped with uniformly-shaped nanoparticles formed in situ.

This section is centered on the challenge of finding near term applications of quantum computers in real-life problems and setting up the foundations for a national quantum computing industry. The chapter shows the strategic value of quantum computing research at CSIC, as well as the opportunities and challenges ahead.

Deposition of the top-contact electrode to create large-area electrode | monolayer | electrode junctions represents a contemporary challenge to the integration of molecular electronic phenomena into device structures. Here, a top contact electrode is formed on top of an organic monolayer over a large area (cm2) by two simple, sequential self-assembly steps. Initial self-assembly of 4,4′-(1,4-phenylenebis(ethyne-2,1-diyl))dianiline onto gold-on-glass substrates gives high-quality monolayers. The exposed amine functionality is subsequently used to anchor uncapped gold nanoparticles deposited in a second self-assembly step. These uncapped gold nanoparticles are prepared by thermolysis of lipoic acid stabilized gold nanoclusters and contain gold oxide (≈9%) that provides stability in the absence of an organic capping ligand. This two-step procedure results in full coverage of the monolayer by the densely packed gold nanoparticles, which spontaneously condense to give a semi-continuous film. The electrical properties of these junctions are determined from I–V curves, revealing uniform electrical response and absence of metallic short-circuits or evidence of damage to the underlying molecular monolayer. These promising electrical characteristics suggest that the deposition of uncapped gold nanoparticles on suitably functionalized molecular monolayers provides a path for the fabrication of molecular electronic devices using simple methodologies.

Procedimiento de transferencia de motivos micro- y/o nano- estructurados a superficies arbitrarias. La presente invención se refiere a un procedimiento de transferencia de motivos micro- y/o nano- estructurados de alta resolución a superficies arbitrarias, a partir de la utilización y la manipulación de una lámina de sacrificio. Además, en el procedimiento de la presente invención, los motivos micro- y/o nano- estructurados de la lámina de sacrificio se transfieren de manera que quedan en contacto directo con la superficie de interés, sin el uso de un material adhesivo como interfaz. Por tanto, la presente invención se puede encuadrar en el área del procesado de superficies.

La presente invención se refiere a un procedimiento de transferencia de motivos micro- y/o nano- estructurados de alta resolución a superficies arbitrarias, a partir de la utilización y la manipulación de una lámina de sacrificio. Además, en el procedimiento de la presente invención, los motivos micro- y/o nano- estructurados de la lámina de sacrificio se transfieren de manera que quedan en contacto directo con la superficie de interés, sin el uso de un material adhesivo como interfaz. Por tanto, la presente invención se puede encuadrar en el área del procesado de superficies. [ES], The present invention refers to a method for transferring high-resolution micro- and/or nano-structured patterns to arbitrary surfaces, based on the use and manipulation of a sacrificial sheet. Furthermore, in the method of the present invention, the micro- and/or nano-structured patterns of the sacrificial sheet are transferred in such a way that they are in direct contact with the surface of interest, without using an adhesive material as an interface. Consequently, the present invention can be classified in the field of surface processing. [EN]

An accurate knowledge of the parameters governing the kinetics of block copolymer self-assembly is crucial to model the time- and temperature-dependent evolution of pattern formation during annealing as well as to predict the most efficient conditions for the formation of defect-free patterns. Here, the self-assembly kinetics of a lamellar PS-b-PMMA block copolymer under both isothermal and non-isothermal annealing conditions are investigated by combining grazing-incidence small-angle X-ray scattering (GISAXS) experiments with a novel modelling methodology that accounts for the annealing history of the block copolymer film before it reaches the isothermal regime. Such a model allows conventional studies in isothermal annealing conditions to be extended to the more realistic case of non-isothermal annealing and prediction of the accuracy in the determination of the relevant parameters, namely the correlation length and the growth exponent, which define the kinetics of the self-assembly.

This contribution explores different strategies to electrically contact vertical pillars with diameters less than 100 nm. Two process strategies have been defined, the first based on Atomic Force Microscope (AFM) indentation and the second based on planarization and reactive ion etching (RIE). We have demonstrated that both proposals provide suitable contacts. The results help to conclude that the most feasible strategy to be implementable is the one using planarization and reactive ion etching since it is more suitable for parallel and/or high-volume manufacturing processing.

Inspired by geometrically frustrated magnetic systems, we present the optical response of three cases of hexagonal lattices of plasmonic nanoelements. All of them were designed using a metal-insulatormetal configuration to enhance absorption of light, with elements in close proximity to exploit near-field coupling, and with triangular symmetry to induce frustration of the dipolar polarization in the gaps between neighboring structures. Both simulations and experimental results demonstrate that these systems behave as perfect absorbers in the visible and/or the near infrared. Besides, the numerical study of the time evolution shows that they exhibit a relatively extended time response over which the system fluctuates between localized and collective modes. It is of particular interest the echoed excitation of surface lattice resonance modes, which are still present at long times because of the geometric frustration inherent to the triangular lattice. It is worth noting that the excitation of collective modes is also enhanced in other types of arrays where dipolar excitations of the nanoelements are hampered by the symmetry of the array. However, we would like to emphasize that the enhancement in triangular arrays can be significantly larger because of the inherent geometric incompatibility of dipolar excitations and three-fold symmetry axes.

Extreme ultraviolet interference lithography (EUV-IL) is used to manufacture topographical guiding patterns to direct the self-assembly of block copolymers. High-accuracy silicon oxide-like patterns with trenches ranging from 68 nm to 117 nm width are fabricated by exposing a hydrogen silsesquioxane (HSQ) resist layer using EUV-IL. We investigate how the accuracy, the low line width roughness and the low line edge roughness of the resulting patterns allow achieving DSA line/space patterns of a PS-b-PMMA (polystyrene-block-poly methyl methacrylate) block copolymer of 11 nm half-pitch with low defectivity. We conduct an in-depth study of the dependence of the DSA pattern morphology on the trench width and on how the neutral brush covers the guiding pattern. We identify the relation between trench width and the emergence of defects with nanometer precision. Based on these studies, we develop a model that extends available free energy models, which allows us to predict the patterning process window.

In this paper, we investigate the directed self-assembly of block copolymers in topographical guiding patterns with feature sizes in the range of the block copolymer half-pitch. In particular, we present the self-assembly of an 11.7 nm half-pitch block copolymer in sub-10 nm resolution guiding patterns fabricated by the direct e-beam exposure of hydrogen silsesquioxane (HSQ). One result of this analysis is that the block copolymer self-assembles such that the guiding pattern features form part of the 3-D architecture of the film. We are capable of determining a shift in the block copolymer pitch as a function of the guiding pattern pitch with sub-nanometer accuracy by means of both real-space (AFM, SEM) and reciprocal-space techniques (GISAXS). An interesting result is that the block copolymer self-assembly in the studied structures depends on the guiding pattern pitch rather than on the trench width as in standard graphoepitaxy. We analyze the structures by means of a free energy model and present both theoretical and experimental evidence of a narrower processing window for such kind of guiding patterns than for regular directed self-assembly using wide topographical guiding patterns, and discuss the origin of this effect. We argue that chain deformation in the vicinity of the top cap of the guiding pattern feature is responsible for an increase of the free energy of the ordered state, which leads to a smaller energy difference between the defect-free and defective self-assembly than that for the observed self-assembly morphology.

This paper presents mechanical actuation experiments performed on ultrathin suspended nanoscale silicon devices presenting Euler buckling. The devices are fabricated by a combination of focused ion beam (FIB) implantation and selective wet etching. By loading the center of curved nanobeams with an atomic force microscope (AFM) tip the beams can be switched from an up-buckled position to the opposite down-buckled configuration. It is possible to describe the entire snap-through process thanks to the presence of strong capillary forces that act as physical constraint between the tip and the device. The experiments conducted recall the same behavior of macro and microscale devices with similar geometry. Curved nanobeams present a bistable behavior, i.e. they are stable in both configurations, up or down-buckled. In addition to that, by the method presented, it is possible to observe the dynamic of a mechanical switch at the nanoscale.

We present the fabrication, operation, and CMOS integration of arrays of suspended silicon nanowires (SiNWs). The functional structures are obtained by a top-down fabrication approach consisting in a resistless process based on focused ion beam irradiation, causing local gallium implantation and silicon amorphization, plus selective silicon etching by tetramethylammonium hydroxide, and a thermal annealing process in a boron rich atmosphere. The last step enables the electrical functionality of the irradiated material. Doubly clamped silicon beams are fabricated by this method. The electrical readout of their mechanical response can be addressed by a frequency down-mixing detection technique thanks to an enhanced piezoresistive transduction mechanism. Three specific aspects are discussed: i) the engineering of mechanically coupled SiNWs, by making use of the nanometer scale overhang that it is inherently-generated with this fabrication process, ii) the statistical distribution of patterned lateral dimensions when fabricating large arrays of identical devices, and iii) the compatibility of the patterning methodology with CMOS circuits. Our results suggest that the application of this method to the integration of large arrays of suspended SiNWs with CMOS circuitry is interesting in view of applications such as advanced radio frequency band pass filters and ultra-high-sensitivity mass sensors.

In recent years, block copolymer lithography has emerged as a viable alternative technology for advanced lithography. In chemicalepitaxy- directed self-assembly, the interfacial energy between the substrate and each block copolymer domain plays a key role on the final ordering. Here, we focus on the experimental characterization of the chemical interactions that occur at the interface built between different chemical guiding patterns and the domains of the block copolymers. We have chosen hard X-ray high kinetic energy photoelectron spectroscopy as an exploration technique because it provides information on the electronic structure of buried interfaces. The outcome of the characterization sheds light onto key aspects of directed self-assembly: grafted brush layer, chemical pattern creation and brush/block co-polymer interface.

The implementation of three-dimensional (3D) nano-objects as building blocks for the next generation of electro-mechanical, memory and sensing nano-devices is at the forefront of technology. The direct writing of functional 3D nanostructures is made feasible by using a method based on focused ion beam induced deposition (FIBID). We use this technique to grow horizontally suspended tungsten nanowires and then study their nano-mechanical properties by three-point bending method with atomic force microscopy. These measurements reveal that these nanowires exhibit a yield strength up to 12 times higher than that of the bulk tungsten, and near the theoretical value of 0.1 times the Young's modulus (E). We find a size dependence of E that is adequately described by a core-shell model, which has been confirmed by transmission electron microscopy and compositional analysis at the nanoscale. Additionally, we show that experimental resonance frequencies of suspended nanowires (in the MHz range) are in good agreement with theoretical values. These extraordinary mechanical properties are key to designing electro-mechanically robust nanodevices based on FIBID tungsten nanowires.

Nascent metal|monolayer|metal devices have been fabricated by depositing palladium, produced through a CO-confined growth method, onto a self-assembled monolayer of an amine-terminated oligo(phenylene ethynylene) derivative on a gold bottom electrode. The high surface area coverage (85%) of the organic monolayer by densely packed palladium particles was confirmed by X-ray photoemission spectroscopy (XPS) and atomic force microscopy (AFM). The electrical properties of these nascent Au|monolayer|Pd assemblies were determined from the I-V curves recorded with a conductive-AFM using the Peak Force Tunneling AFM (PF-TUNA™) mode. The I-V curves together with the electrochemical experiments performed rule out the formation of short-circuits due to palladium penetration through the monolayer, suggesting that the palladium deposition strategy is an effective method for the fabrication of molecular junctions without damaging the organic layer.

Nanostructured gratings of semicrystalline polymers like poly(propylene azelate) (PPAz) or of ferroelectric copolymers of vinylidene uoride(VDF) and triuoroethylene(TrFE) have been prepared over spin-coated thin lms by Nanoimprint Lithography (NIL). The structure and morphology of the gratings have been investigated by combining Atomic Force Microscopy (AFM) and Grazing Incidence X-ray Scattering at small angle (GISAXS) and wide angle (GIWAXS). The results reveal that NIL aects signicantly the orientation of the crystalline lamellae. In both cases gratings are more abundant in edge-on lamellae than the reference non-printed lms. For PPAz we attribute this eect to the preferential crystallization as at-on lamellae on silicon surfaces either the stamp trench walls or the substrate surface. Thus, the at-on lamellae on the trench walls appear to be edge-on lamellae in the printed sample. These results further support NIL as an appropriate procedure in order to control polymer crystal orientation.

The nonlinear interaction between an AFM tip and a sample in tapping mode atomic force microscopy (TM-AFM) induces an anharmonic cantilever motion that can be expressed in terms of a Fourier series with amplitude coefficients and frequencies multiples of the fundamental frequency, known as higher harmonics. The amplitudes of such higher harmonics can be expressed in terms of both tip and sample parameters, e.g., the tip radius (R) and the sample Young’s modulus (E). Here we present a method that describes the dependence of the amplitudes of the 6th and 7th higher harmonics to with R and E. This method has been applied to rectangular silicon cantilevers with force constant around 26 N/m and fundamental frequencies in the 250-350 kHz range. During TM-AFM imaging we simultaneously acquire the topography, the phase of the 1st (fundamental) eigenmode and the amplitude of the 6th or 7th higher harmonic, respectively. The frequency of the 6th harmonic is nearly in resonance with the frequency of the 2nd flexural mode. The information extracted from the images has been compared with those from amplitude curves and with computer simulations obtained using the Virtual Environment for Dynamic AFM (VEDA) open code. in order to extrapolate a model of the 6th and 7th higher harmonic amplitude depending on the cantilever and measurement parameters and then go beyond the qualitative interpretation. The obtained results have been complemented with standard methods to calibrate the radius using tip calibration samples of gold nano-particles (5.5 nm mean radius) on mica substrates and compared to measurements performed using the Peak Force technique.

Redox cycling (RC) is a unique electrochemical technique to selectively detect redox-active species in presence of molecules with similar oxidation potential but whose electrochemical reactions display different electron transfer kinetics. Pairs of interdigitated electrodes (IDEs) working as generator-collector devices have been widely applied in RC. The diffusion of species that takes place between the two IDEs has to be minimized in order to enhance the device sensitivity. Therefore, scaling down the IDE dimensions is carried out to detect very low concentrations of the molecules under study. The application of interdigitated nanoelectrode structures (nano-IDEs) is currently limited by low-yield production and packaging processes. Here, we describe a fabrication approach that enables robust mass production of gold nano-IDEs at wafer scale, along with a packaging strategy to easily operate with the electrodes. The theoretical and experimental detection of dopamine in presence of ascorbic acid demonstrates the superior analytical performance of the resulting devices. Nano-IDEs with dimensions of 150 nm width and 300 nm pitch showed faradaic steady-state currents related to the oxidation of dopamine that were 16.7 times larger than those recorded by standard cyclic voltammetry. By contrast, if the dimensions of the nano-IDEs are increased by a factor of 10, the amplification factor of the redox reaction is decreased to less than one fourth.

In this contribution the photoreduction of silver ions coordinated onto a Langmuir-Blodgett monolayer is presented as an effective method for the deposition of the top contact electrode in metal/monolayer/metal devices. Silver cations were incorporated from an aqueous AgNO sub-phase of Langmuir films of 4,4′-(1,4-phenylenebis(ethyne-2,1-diyl))dibenzoic acid upon the transference of these films onto a metallic substrate. Subsequent irradiation of the silver-ion functionalized Langmuir-Blodgett films with 254 nm light results in the photoreduction of silver cations to produce metallic silver nanoparticles, which are distributed over the organic monolayer and exhibit a surface coverage as large as 76% of the monolayer surface. Electrical properties of these metal/monolayer/metal devices were determined by recording I-V curves, which show a sigmoidal behaviour indicative of well-behaved junctions free of metallic filaments and short-circuits. The integrity of the organic monolayer upon the irradiation process and formation of the silver top-contact electrode has also been demonstrated through cyclic voltammetry experiments.

Within the www.aim4np.eu project, a metrology platform hosting an Atomic Force Microscope [AFM] will be used for the determination of the nanomechanical properties of surfaces of objects at a production site enabling inline process control.

Within the www.aim4np.eu project, a metrology platform hosting an Atomic Force Microscope [AFM] will be used for the determination of the nanomechanical properties of surfaces of objects at a production site enabling inline process control. Under the nanomechanical properties term we include roughness, adhesion and elasticity. The underlying concept is based on the artificially generated stiffness between the surface to be characterized and the metrology platform using a feedback sensor-actuator system. Plastic injection was chosen as a case system for the validation-study. The goal is to determine the influence of the surface micro/nano roughness of a mould and the performance of the injection moulding process. The determination of the link between the nanomechanical properties of the surface of the mould and the functionality of the mould (that is the surface roughness and defect density of the moulded plastic part) is addressed both by means of experimental and simulation techniques. Moulds and moulded plastic parts have been characterized by AFM and other techniques, and computer models have been developed to simulate the effect of mould surface roughness on the appearance of the final plastic piece. All available simulation codes devoted to plastic injection have so far been conceived for large pieces in industrial applications (e.g. automotive) with critical dimensions well above the millimetre range. Thus, it was foreseeable that the extension of such codes down to the micro- and nanometre range would be challenging, given the used approximations and boundary conditions in the codes. For this reason, the emphasis was initially laid on the experimental part to address the relevant magnitudes of parameters of technical surfaces, such as roughness and morphology. Trying to directly replicate the roughness of the mould surface was a too demanding objective. It was therefore decided to start with the study of well-defined simple patterns in the micrometre-range. D

The effect of geometrical asymmetries on the piezoresistive transduction in suspended double clamped beam nanomechanical resonators is investigated. Tapered silicon nano-beams, fabricated using a fast and flexible prototyping method, are employed to determine how the asymmetry affects the transduced piezoresistive signal for different mechanical resonant modes. This effect is attributed to the modulation of the strain in pre-strained double clamped beams, and it is confirmed by means of finite element simulations.

The extraordinary strength, stiffness and lightness of graphene have generated great expectations of its application in flexible electronics and as a mechanical reinforcement agent. However, the presence of lattice defects, unavoidable in sheets obtained by scalable routes, might degrade its mechanical properties. Here we report a systematic study on the elastic modulus and strength of graphene with a controlled density of defects. Counter-intuitively, the in-plane Youngâ €™ s modulus increases with increasing defect density up to almost twice the initial value for a vacancy content of â 1/40.2%. For a higher density of vacancies, the elastic modulus decreases with defect inclusions. The initial increase in Youngâ €™ s modulus is explained in terms of a dependence of the elastic coefficients on the momentum of flexural modes predicted for two-dimensional membranes. In contrast, the fracture strength decreases with defect density according to standard fracture continuum models. These quantitative structure-property relationships, measured in atmospheric conditions, are of fundamental and technological relevance and provide guidance for applications in which graphene mechanics represents a disruptive improvement.

© 2015 Elsevier Ltd. All rights reserved. Nanostructured gratings of semicrystalline poly(propylene azelate) (PPAz) have been prepared over spin-coated thin films by Nanoimprint Lithography (NIL). The structure and morphology of the gratings have been investigated by combining Atomic Force Microscopy (AFM) and Grazing Incidence X-ray Scattering at small angle (GISAXS) and wide angle (GIWAXS). The results reveal that NIL affects significantly the orientation of the crystalline lamellae. PPAz gratings are more abundant in edge-on lamellae than the reference non-printed films. We attribute this effect to the PPAz preferential crystallization as flat-on lamellae on silicon surfaces either the stamp trench walls or the substrate surface. Thus, the flat-on lamellae on the trench walls appear to be edge-on lamellae in the printed sample. These results further support NIL as an appropriate procedure in order to control polymer crystal orientation.