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Li and Na metals have the highest theoretical anode capacity for Li/Na batteries, but the operational safety hazards stemming from uncontrolled growth of Li/Na dendrites and unstable electrode-electrolyte interfaces hinder their real-world applications. Recently, the emergence of 3D conductive scaffolds aimed at mitigating the dendritic growth to improve the cycling stability has gained traction. However, while achieving 3D scaffolds that are conducive to completely prevent dendritic Li/Na is challenging, the routes proposed to fabricate 3D scaffolds to date are often complex and expensive. This not only leads to sub-optimal battery performance but can make the manufacturing nearly unachievable, compromising their commercial viability. We herein introduce a facile and single-step route to honeycomb-like 3D porous Ni@Cu scaffolds via a hydrogen bubble dynamic template (HBDT) electrodeposition method. The current collectors fabricated by this method offer highly stable cycling performance of Li plating/stripping (>300 cycles at 0.5 mAh cm−2 and over 200 cycles at 1.0 mAh cm−2), attributed to their ability to effectively accommodate Li/Na deposits in their porous networks and to delocalize the charge distribution. The beneficial role of LiNO3 as an electrolyte additive in improving the mechanical integrity of solid electrolyte interface (SEI) and mechanistic insights into how the 3D porous structure facilitates Li/Na plating/stripping are comprehensively presented. Finally, with an outstanding cycling performance of reversible Na deposition (over 240, 110 and 50 cycles for 0.5, 1.0 and 2.0 mAh cm−2 at 1.0 mA cm−2), our findings open new doors to expedite the development of Li/Na metal battery technology. © 2017

Determination of the structural response of a structural element under blast loading is of interest to vulnerability / lethality (V/L) studies of military operations in urban terrain. These studies require a quick and easy to use method to simulate the structural response of e.g. a wall under non-uniform loading conditions. The single degree of freedom model (SDOF) provides a very efficient method to schematize and predict the response of structures subjected to dynamic loads. SDOF-model parameters are for many element types tabulated in textbooks. However these

The calibration of a user-defined blast model implemented in LS-DYNA is presented using full-scale test rig experiments, partly according to the NATO STANAG 4569 AEP-55 Volume 2 specifications where the charge weight varies between 6 kg and 10 kg and the burial depth is 100 mm and deeper. The model calibration is performed on the specific impulse obtained from the Westine empirical model and on the shape of the applied triangular pressure profile (peak pressure and duration). The verification between the model and the experiments is based on global effects (jump height and total impulse transferred to the test rig) as well as local effects (deformation of the local plate). ALE simulations of the mine blast loading event are also presented and compared with the userdefined blast model and experiments. The results show that the load from the ALE simulations is in good agreement with the user-defined blast model for shallow buried small charges, but is under-estimated for deep buried and heavy charges.

The development of new bottom concepts for military vehicles against mine blast threats involves the consideration of two main aspects: the bottom geometry and the material used. In order to reduce costs, experimental testing of new vehicle bottom concepts often requires small-scale setups together with numerical simulations to assist the design and development process. This study first presents the validation of a numerical blast model for bare charges using experimental freefield blast data. An investigation of the reflected pressure on a flat plate shows the

The maximum amount of repulsive force applied to the surface plays a very important role in damage of tip or sample in Atomic Force Microscopy(AFM). So far, many investigations have focused on peak repulsive forces in tapping mode AFM in steady state conditions. However, it is known that AFM could be more damaging in transient conditions. In high-speed scanning, and in presence of 3D nano structures (such as FinFET), the changes in topography appear in time intervals shorter than the response time of the cantilever. In this case, the tip may crush into the sample by exerting much higher forces than for the same cantilever-sample distance in steady state situations.In this study the effects of steep upward steps in topography on the tip-sample interactions have been investigated, and it has been found that the order(s) of magnitude higher forces can be applied. The information on the worst case scenario obtained by this method can be used for selection of operation parameters and probe design to minimize damage in high-speed imaging. The numerically obtained results have been verified with the previous works in steady state regime. Based on this investigation the maximum safe scanning speed has been obtained for a case study.

With the device dimensions moving towards the 1X node and below, the semiconductor industry is rapidly approaching the point where existing metrology, inspection and review tools face huge challenges in terms of resolution, the ability to resolve 3D and the throughput. Due to the advantages of sub-nanometer resolution and the ability of true 3D scanning, scanning probe microscope (SPM) and specifically atomic force microscope (AFM) are considered as alternative technologies for CD-metrology, defect inspection and review of 1X node and below. In order to meet the increasing demand for resolution and throughput of CD-metrology, defect inspection and review, TNO has previously introduced the parallel SPM concept, consisting of parallel operation of many miniaturized SPMs on a 300 and 450 mm wafer. In this paper we will present the proof of principle of the parallelization for metrology and inspection. To give an indication of the system’s specifications, the throughput of scanning is 4500 sites per hour, each within an area of 1 μm2 and 1024 ×1024 pixels.

This paper aims at unraveling the mystery of damage in high speed AFMs for 1X node and below. With the device dimensions moving towards the 1X node and below, the semiconductor industry is rapidly approaching the point where existing metrology, inspection and review tools face huge challenges in terms of resolution, the ability to resolve 3D, and throughput. In this paper, we critically asses the important issue of damage in high speed AFM for metrology and inspection of semiconductor wafers. The issues of damage in four major scanning modes (contact mode, tapping mode, non-contact mode, and peak force tapping mode) are described to show which modes are suitable for which applications and which conditions are damaging. The effects of all important scanning parameters on resulting damage are taken into account for materials such as silicon, photoresists and low K materials. Finally, we recommend appropriate scanning parameters and conditions for several use cases (FinFET, patterned photoresist, HAR structures) that avoid exceeding a critical contact stress such that sample damage is minimized. In conclusion, we show using our theoretical analysis that selecting parameters that exceed the target contact stress, indeed leads to significant damage. This method provides AFM users for metrology with a better understanding of contact stresses and enables selection of AFM cantilevers and experimental parameters that prevent sample damage.

A special porous concrete has been developed by the Delft University in collaboration with TNO. The concrete has a static compressive strength of 45 MPa. It fragments at impact into small size debris relative to reference concrete. The porous concrete was developed at laboratory scale and tested at small scale. In collaboration with the Military Science faculty of NLDA a procedure was developed to upscale the production. Panels of 0.5m x 0.5m x 0.10m were produced at slightly lower strength than realized at lab scale. These panels were used to investigate the ballistic performance of the porous concrete. The ballistic resistance proved to be comparable to that of reference concrete. The instant crushing feature of the concrete causes additional damage at the front side but the damage zone was still limited in size. Spalling at the rear side proved to be limited in comparison to the reference normal concrete. To further improve the ballistic resistance of the porous concrete, it was infiltrated with a polymer. Tests showed a considerable improvement of the penetration resistance, relative to the noninfiltrated porous concrete. The paper first summarizes the characteristics of the porous concrete developed at lab scale. The ballistic test data are presented and analyzed. The ballistic response mechanism of the porous concrete is compared with the mechanism in normal concrete. From this analysis the alternative of filling the pores emerges. Finally the paper presents the initial ballistic results for the infiltrated porous concrete.

One of the major limitations in the speed of the atomic force microscope (AFM) is the bandwidth of the mechanical scanning stage, especially in the vertical (z) direction. According to the design principles of “light and stiff” and “static determinacy,” the bandwidth of the mechanical scanner is limited by the first eigenfrequency of the AFM head in case of tip scanning and by the sample stage in terms of sample scanning. Due to stringent requirements of the system, simply pushing the first eigenfrequency to an ever higher value has reached its limitation. We have developed a miniaturized, high speed AFM scanner in which the dynamics of the z-scanning stage are made insensitive to its surrounding dynamics via suspension of it on specific dynamically determined points. This resulted in a mechanical bandwidth as high as that of the z-actuator (50 kHz) while remaining insensitive to the dynamics of its base and surroundings. The scanner allows a practical z scan range of 2.1 μm. We have demonstrated the applicability of the scanner to the high speed scanning of nanostructures.

The majority of methods to assess the behind armour blunt trauma (BABT) risk for ballistic helmets is based on plastic deformable headforms. An alternative, the Ballistic Load Sensing Headform (BLSH) can record the dynamic contact force between helmet back face and the skull. Helmet BABT methods are still under development and outcomes are highly sensitive to test procedures. A test method for the BLSH has been developed, as there was no method available, and evaluated in a round robin series performed by three laboratories, using the same procedure and their own headform, data acquisition and processing. Helmets were tested three times at front, rear and both lateral sides. Peak contact force is used as performance criterion. The peak force varies between 3.536 kN and 10.110 kN depending on location. This is to a large extend caused by a significant variation in stand-off which occurs despite the strict positioning procedure of the helmet. Results become more consistent by statistically correlating peak force and stand-off. However a significant spread within each laboratory remains, which needs further exploration. It is expected that peak force is too sensitive as it is a high frequency phenomena and the tested helmets are not designed to control nor optimize the BABT contact force. It appears that there is systematic difference between laboratories which is not understood. The helmet BABT risk assessment method needs further development to allow inter laboratory comparison and is therefore not acceptable for a test standard. However it is very useful for research purposes and helmet optimisation knowing the vulnerable and sensitive aspects. The scattered response requires a statistical approach and consequently multiple helmet test are required to allow for meaningful conclusions.

In this study, we report high-quality amorphous indiunrv-galiium-zinc-oxide (a-IGZO) thinfilm transistors (TFTs) fabricated on a polyethylene naphthalate foil using a new back-channel-etch (BCE) process flow. The BCE flow allows a better scalability of TFTs for high-resolution backplanes and related circuits. The maximum processing temperature was limited to less than lôS'C in order to ensure good overiay accuracy (

The first direct measurement is reported of the bulk density of deep states in amorphous IGZO (indium-gallium-zinc oxide) semiconductor by means of deep-level transient spectroscopy (DLTS). The device under test is a Schottky diode of amorphous IGZO semiconductor on a palladium (Pd) Schottky-barrier electrode and with a molybdenum (Mo) Ohmic contact at the top. The DLTS technique allows to independently measure the energy and spatial distribution of subgap states in the IGZO thin film. The subgap trap concentration has a double exponential distribution as a function energy, with a value of ∼10 19 cm-3 eV-1 at the conduction band edge and a value of ∼1017 cm-3 eV-1 at an energy of 0.55 eV below the conduction band. Such spectral distribution, however, is not uniform through the semiconductor film. The spatial distribution of subgap states correlates well with the background doping density distribution in the semiconductor, which increases towards the Ohmic Mo contact, suggesting that these two properties share the same physical origin. cop. 2014 AIP Publishing LLC.

TNO has developed an alternative, more configuration independent ceramic test method than the standard Depth-of-Penetration test method. In this test ceramic tiles and ceramic based armor are evaluated as target without a semi-infinite backing layer. An energy approach is chosen to evaluate and rank the target materials penetration resistance. By measuring the armor material’s energy absorption, subtracting the residual projectile energy after penetration from the projectile energy before impact, an objective performance parameter for the ceramic or ceramic based armor is obtained. However, this parameter is still related to the specific projectile used in the test. The presented alternative testing method for ceramic based armor uses a high speed camera technique to determine residual velocity of target material fragments and of projectile remains. The residual mass of the projectile is determined, capturing the penetrated projectile (and ceramic fragments) in a water basin. Analysis of the projectile remains after the impact event, provides valuable information on the two projectile to target interaction stages, dwell and penetration. The test method and analysis method are described in this paper. Results on ceramic and ceramic based armor are presented and discussed.

Anti-vehicle (AV) mines and Improvised Explosive Devices (IEDs) pose a major threat in recent and current missions. In the latest operational theatres of Iraq and Afghanistan they have been responsible for a significant proportion of all casualties. Understanding both the characteristics and strength of the blast loading from these devices is essential for both the design and evaluation of mine-blast resistant vehicles. As part of this process TNO evaluated a range of TNT and ANFO buried charges. Selected results from these tests are reported here. Whilst TNT is a common military explosive, ANFO is readily available to insurgents and forms the actual threat. A buried charge will focus the blast towards the vehicle due to the explosive interaction with the soil. The loading characteristic from the detonated charge is a combination of the power (brisance) and strength (heave effect) of the explosive. Whilst TNT is more powerful than ANFO with a higher brisance, ANFO has a higher observed strength than TNT with a higher heaving effect. The ANFO and TNT experimental results are being used to develop and validate the TNO Mine Blast Model [1] implemented into the commercial code LSDYNA. This provides a numerically efficient and robust method for simulating a buried mine blast.

The introduction, analysis or development of soldier systems presents many questions regarding the optimum of possible combinations of burden, effectiveness and safety of the soldier system. The soldier is subject to a broad spectrum of physical loads as a consequence of the threats being encountered. Often, the individual burdens are treated and analysed independently, but the interdependence of the burdens require an integrated approach. In the future such a model can be used to e.g. guide decisions for procurement of clothing and equipment or to guide future needs for development. The initial steps in constructing such an integral model are presented here. The model is called COBESE (COst BEnefit model for Soldier system Evaluation). The focus for the current iteration COBESE model lies on the trade-off between mobility and vulnerability (i.e. the physical safety). COBESE aims to integrate existing models with expert judgement in order to model the influence of clothing and equipment (costs) on an individual soldier’s mobility (benefits). This integration qualitative and quantitative data is achieved using a Bayesian Belief Network (BBN) approach. This paper describes the choices, underlying structure and the implemented sub-models of the COBESE model. Furthermore, case studies are performed to demonstrate the functionality and benefits of the model.

Porous concrete is a special type of cementitious material incorporating a high amount of meso-size air pores that makes its characteristics markedly different from normal concrete. Therefore, it is being investigated for various applications, aiming to benefit from the presence of the air voids in its structure, such as permeability, noise absorption or thermal insulation. While its performance in various fields of usage is of high interest, the behavior of porous concrete under impact loading is not as widely investigated. A research project was undertaken to design a special type of porous concrete, that fractures into small fragments when exposed to impact loading while having sufficient static strength, to be used in protective structures such as safety walls or storages for explosives. The project comprised of both experimental and numerical analyses that have been conducted to investigate the porous concrete material, especially in terms of its impact behavior, and to understand the parameters that control its performance, which are significantly different from those of normal concrete. In the currently presented study, some of the experimental methods and results from impact experiments as well as representative results from the numerical analyses have been presented.

Organic light-emitting diodes (OLEDs) are a promising lighting technology. In particular OLEDs fabricated on plastic foils are believed to hold the future. These planar devices are subject to various optical losses, which requires sophisticated light management solutions. Flexible OLEDs on plastic substrates are as prone to losses related to wave guiding as devices on glass. However, we determined that OLEDs on plastic substrates are susceptible to another loss mode due to wave guiding in the thin film barrier. With modeling of white polymer OLEDs fabricated on PEN substrates, we demonstrate that this loss mode is particularly sensitive to polarized light emission. Furthermore, we investigated how thin film barrier approaches can be combined with high index light extraction layers. Our analysis shows that OLEDs with a thin film barrier consisting of an inorganic/organic/inorganic layer sequence, a low index inorganic negatively affects the OLED efficiency. We conclude that high index inorganics are more suitable for usage in

Structural design methods for naval ships include environmental, operational and military load cases. One of the operational loads acting on a typical naval vessel is the muzzle blast from a gun. Simulating the muzzle blast load acting on a ship structure with CFD and ALE methods leads to large numerical models with high CPU requirements as a large volume of the surrounding air domain requires meshing. A numerically efficient method is required to determine the limits of the gun orientation (azimuth and elevation) for the ship structure. When a gun is fired at particular orientations, the structure in the vicinity of the muzzle may be subjected to high loads. This is of particular interest for the latest naval designs which employ thin decking in order to minimize structural weight and cost. A modified version of the Heaps, Fansler and Schmidt [1], Fansler [2] analytical blast model has been implemented into LSDYNA as a user defined muzzle blast load. This is implemented in a similar manner to the TNO Mine Blast Model [3]. The muzzle blast loading model enables the structural response to be evaluated in a numerically efficient manner.

Tunnel accidents with transports of dangerous goods may lead to explosions. Risk assessment for these accidents is complicated because of the low probability and the unknown, but disastrous effects expected. Especially the lack of knowledge on the strength of the explosion and the consequences for the tunnel user, the tunnel lining and the consequences for the surroundings and adjacent structures, hampers the quantitative risk assessment. Decisions on the routing of the dangerous goods transports cannot be supported by quantitative risk analysis (QRA) without knowledge on the explosion mechanisms and the ability to predict the explosion strength for accident scenarios. The common knowledge proved to be insufficient for this risk evaluation. Based on the expertise on explosions, reactive gas dynamics and CFD expertise, TNO developed engineering models to quantify the explosion load and consequences. This paper presents (i) the different types of explosions and the related scenario conditions, (ii) the explosion models and representative explosion loads and (iii) illustration of the consequences. A comparison with the guidelines given in the Eurocode is made and shows that these guidelines are not suitable for risk assessment and tunnel design. The engineering models presented in this paper give the required input for QRA. It is shown that a variety of explosion strengths may occur and that not all explosion scenarios lead to disastrous effects. For the transport of dangerous goods through tunnels a wide scope of explosion scenarios has to be and can be considered.

The fragmentation of ceramic tiles under ballistic impact has been studied. Fragments and aerosol (respirable) particles were collected and analyzed to determine the total surface area generated by fracturing (macro-cracking and comminution) of armor grade ceramics. The larger fragments were collected and the mass distribution was obtained from sieving. The aerosol particles were collected using a particle impactor device that counts the number of particles of specific ranges in size. From the total surface area of all particles was concluded that fracture energy is small compared to impact energy. The average grain size of the ceramic tiles did not lead to a specific peak in mass or concentration for that particle size. In fact, a large concentration of much finer particles has been obtained. The size of the aerosol dust ranged between 10 micron and 10 nanometers, indicating a lot of particle fragmentation (comminution) to have taken place.

In order use material models in (numerical) calculations, the mechanical properties of all materials involved should be known. At TNO an indirect method to determine the dynamic flow stress of materials has been generated by a combination of ballistic penetration tests with an energy-based engineering model. For visco-elasto-plastic materials, like clay, not only the dynamic flow stress is strain rate dependent, but also its Young’s modulus. Experiments using 7.62x39 MSC bullets have been performed on Roma Plastilina nr. 1 at several target temperatures. The dynamic flow stress and young’s moduli have been determined using an adjusted ductile hole growth engineering model for weak materials.

Safety evaluation, risk assessment and decisions on prevention and protection measures require simple fast running methods. It is a challenge to develop a consequence analysis method that is relatively simple, but still has the ability to discern between different cases, scenarios and buildings. In the past years, TNO has participated in the FP7 framework project SPIRIT (EU funded) to generate and provide technology and know-how for the protection of buildings and people against terrorist threats and to minimize the consequences of a terrorist threat/attack. In the project a software tool has been developed that enables the user to estimate quantitatively the risks and consequences of terrorist attacks. The SPIRIT tool visualizes the results in an interactive manner. One of the modules in this tool is a module for the prediction of building façade damage due to external blast. A parametric study was carried out of the blast loading on the envelope of different sized buildings and the subsequent damage of façades (within a relevant range of blast resistance). The results were used to develop a method to predict the façade damage in an effective and efficient way. Thanks to a special mapping procedure and a dedicated interpolation procedure, the method can be used for any type of façade with a known resistance level, and for any type of building. This method is incorporated in the damage prediction module in the SPIRIT tool.

In this paper a novel adaptive regenerative braking control concept for electric vehicles with an electric motor at the front axle is presented. It is well known that the "phased" type regenerative braking systems of category B maximize the amount of regenerative energy during braking. However, there is an increased risk of maneuvering capability loss especially during cornering. An integrated braking controller which determines - in a single step - the desired yaw moment and allocates the braking demand between hydraulic brakes and electric motor during cornering is designed using the State Dependent Riccati Equation (SDRE) method. A unique method for deriving the State Dependent Coefficient (SDC) formulation of the system dynamics is proposed. Soft constraints are included in the state dynamics while an augmented penalty approach is followed to handle hard constraints. The performance of the controller has been evaluated for different combined cornering-braking scenarios using simulations in a Matlab/Simulink environment. For this an eight degrees of freedom (DOF) nonlinear vehicle model has been utilized. The numerical results show that the controller is able to optimize (locally) the amount of regenerative braking energy while respecting system's constraints such as tire force saturation, vehicle yaw rate and slip angle errors.

With the device dimensions moving towards the 1X node, the semiconductor industry is rapidly approaching the point where 10 nm defects become critical. Therefore, new methods for improving the yield are emerging, including inspection and review methods with sufficient resolution and throughput. Existing industrial tools cannot anymore fulfill these requirements for upcoming smaller and 3D features, since they are performing at the edge of their performance. Scanning probe microscopy (SPM) has the ability to accurately measure dimensions in the micrometer to nanometer scale. Examples of applications are surface roughness, channel height and width measurement, defect inspection in wafers, masks and flat panel displays. In most of these applications, the target area is very large, and, therefore, the throughput of the measurement plays an important role in the final production cost. Single SPM has never been able to compete with other inspection systems in terms of measurement speed, thus has not fulfilled the industry needs in throughput and cost. Further increase of the speed of the single SPM helps, but it still is far from the required throughput and, therefore, insufficient for high-volume manufacturing. Over the past three years, we have developed a revolutionary concept for a multiple miniaturized SPM heads system, which can inspect and measure many sites in parallel. The very high speed of each miniaturized SPM unit allow the user to scan many areas, each with the size of tens of micrometers, in a few seconds. This paper presents an overview of the technical developments and experimental results of the parallel SPM system for wafer and mask inspection.

This chapter describes the development and properties of novel functional composite materials consisting of aligned piezo-ceramic particles or fibers in a polymeric matrix, which can be fully integrated in thermoset or thermoplastic products. The materials have a low potential for applications requiring actuation but have attractive sensorial and energy harvesting properties. The new composites combine special functionalities with easy processing and adequate mechanical properties close to those of the polymer matrix. Such composite materials may find use in applications such as integrated pressure sensors and energy harvesting devices, which can create a number of new opportunities for the design domain. cop. 2014 Elsevier Inc. All rights reserved.

For the virtual development of steering systems, especially those including electric power steering systems (EPS or EPAS), it is required to have a tyre model that accurately predicts the forces and moments at standstill and manoeuvring at low velocities. This means that the tyre model must be able to deal with combined slip situations of spin, sideslip and longitudinal slip, not only for steady-state, but also for transient behaviour. Recently, TNO updated the turn slip theory originally developed by Pacejka in the latest MF-Swift 6.2 tyre model. Extensive validation with measurements has however been lacking, as suitable tyre test facilities are unavailable. Generally the ‘standard’ centre-point steering experiment is used for parameter identification and model validation. Drawback of this test approach is that only a limited operating range is considered and only a few parameters can be identified. In this study, the applicability of the turn slip model for realistic parking manoeuvres is assessed using vehicle measurements and simulations.

NOVA-ASTRON has delivered a suite of cryogenic astronomical instruments for large ground based telescopes as well as space missions. The instruments include polarimeters, spectrometers, cameras and interferometers, mostly operating at infrared. Several methods have been developed to verify or measure, under cryogenic conditions, the performance of optical components, coatings and complete optical systems. The test and verification setups presented in this paper include wave front error measurements, alignment inspection, spectral measurements, material properties determination and varying gravity orientation capabilities (gravity load vector). The measurement principles are explained, together with the most important error contributions and the achieved accuracies.

Scanning probe microscopy (SPM) is a promising candidate for accurate assessment of metrology and defects on wafers and masks, however it has traditionally been too slow for high-throughput applications, although recent developments have significantly pushed the speed of SPM [1,2]. In this paper we present new results obtained with our previously presented high-throughput parallel SPM system [3,4] that showcase two key advances that are required for a successful deployment of SPM in high-throughput metrology, defect and mask inspection. The first is a very fast (up to 40 lines/s) image acquisition and a comparison of the image quality as function of speed. Secondly, a fast approach method: measurements of the scan-head approaching the sample from 0.2 and 1.0 mm distance in under 1.4 and 6 seconds respectively.

TNO has developed an engineering model for flexible body armor, as one of their energy based engineering models that describe the physics of projectile to target interactions (weaves, metals, ceramics). These models form the basis for exploring the possibilities for protection improvement. This presentation describes how the main physical details of projectile to flexible weave (fabric) interaction can be modeled with a simple set of equations that are based on four well known relations for force, work performed, kinetic energy of a moving material and strain energy in a material and on the two relations for longitudinal wave velocity and cone diameter expansion. The evolution of an impact in the model is based on energy conservation, equal to the summation of kinetic energy in projectile and weave and the strain energy in the armor material. The effect of friction and delamination is excluded. The model allows plasticity of the projectile, strain rate effects on the fiber strength and fiber failure strength as a function of fiber damage due to transverse loading effects. The model is made time resolved, calculating projectile deceleration, weave displacement and straining in a series of calculation steps. The model has created a better understanding, how projectile kinetic energy is transferred into the flexible armour material and how fibre failure and energy absorption in the weave stack are shifted in time. The model has indicated that fibre failure in flexible weave under ballistic impact, is partly initiated by high lateral fiber stress at the location the projectile interacts with the weave stack. This phenomenon is currently investigated at TNO.

At TNO mind sized engineering models are created for specific penetration conditions. The models are energy based and calculate the energy absorbed by target deformation (strain energy) and displacement (kinetic energy). The input parameters are restricted to basic target material properties (density, Young’s modulus), impact velocity, mass and the dimensions of projectile and target. In this paper an engineering model for impact of blunt projectiles on metallic sheets is presented. During blunt projectile impact a shock phase precedes the global deformation of the target. It results in increasing membrane and shear deformation of the target, while the projectile deforms and is retarded. These effects are included in the model. When the conditions for shear- and/or tensile failure of the target material are met, the target fails and is penetrated. Calculation results on projectile deformation and penetration behavior are compared with experimental results.

Depth, diameter and volume of dents in clay backing of soft and hard body armour are used to assess the protective performance of such vests. The characteristics of the dents are traditionally measured manually. Optical scan techniques are becoming more popular and provide an objective method compared to the manual method and it allows to archive the scans for later evaluation. However, commercial high end scanners, accuracy in 1-10 μm, are expensive and there is no software available to automatically determine the dent characteristics. Recently low end scanners, accuracy 0.1-0.5 mm became available. An automatic dent measuring method was developed using Matlab to control a DAVID3 Structured Ligth Scanner and process the scans of the clay backing to obtain the dent characteristics. This SLS dent scan system is presented in this paper. Accuracy of the scans is better than the most strict requirement of 0.5 mm. Scan and processing time to obtain the dent characteristics is less than sixty seconds. The traditional method takes about two minutes between each shot. The accuracy and precision is evaluated by comparison of the SLS scan method with a measurement of a dent by a high end but much slower scanner (accuracy < 0.05 mm). A comparison between the manual and SLS method is made by measuring dents for three clay trays with each five calibration dents and for a soft and hard armour BABT performance assessment. It is concluded that the accuracy of the SLS method is better than or equal to the manual method.

An adaptive mirror control strategy for tuning an optical resonator is described. The control approach is modelfree and uses a small-amplitude perturbation signal to enable real-time estimation of the cost function gradient. The strategy has similarities with the approaches of 'stochastic approximation' and 'extremum seeking control', which are well-known methods in the control community. Particular fine-tuning of the algorithm, such as perturbation filtering, cost function shaping and disturbance feedforward are discussed. The control strategy has been validated on a (quasi-optical) millimetre wave resonator system. A significant disturbance acting on this set-up is the non-stationary frequency of the wave source (gyrotron). In various experiments it has been demonstrated that the control approach is well capable of keeping the optical cavity in resonance, to track wavelength variations and to reject disturbances in the low and mid-frequency range. The only performance limitation of the approach occurs in cases which require fast disturbance tracking. This is due to the bandwidth restrictions in the underlying mirror motion system. © 2013 IEEE.

The handling of explosives and ammunition introduces a safety risk for personnel and third parties. Accidents related to storage, transport and transshipment may result in severe injury and material damage. Dispersion of structural debris is one of the main hazards resulting from detonations inside structures. Reliable prediction models for debris dispersion are essential for risk assessment methods. In this article we give a statistical description of the dispersion of explosion produced debris. The basis is a general expression for the projectile areal number density in the horizontal and vertical plane. Combined with engineering models for the launch conditions, predictions can be made. An analytical solution to the equations of motion may be used to allow for fast calculations. A parameter study shows consistent results. The model has been validated with internal detonation tests of bare charges in reinforced concrete structures. The validation clearly shows the prediction capabilities of the model for three loading regimes described in the literature. We give a thorough description of the validity and limitations of the model, and an outlook of current and future research. Examples are the failing debris mass distribution prediction for reinforced concrete in the shock overloading regime, and ricochet and roll and break-up at impact phenomena.

The Integrated Vehicle Safety Department of TNO (Dutch Organization for Applied Scientific Research) investigates the application of modern control methods in the Integrated Vehicle Dynamics Control (IVDC) field, as a strategic research topic of the Beyond Safe framework. The aim of IVDC is to optimize the vehicle performance by maximizing the synergy between vehicle system like braking, suspension and steering systems and thereby enable improvements in the vehicle safety and comfort for all driving conditions. This article presents the first steps undertaken by the authors to develop and experimentally evaluate an optimal IVDC strategy for stability control using only the braking system. More specifically it presents the structure of the controller, the vehicle and tire models used, the State Dependent Riccati Equation (SDRE) control technique and the experimental evaluation.

Future mobility requires sound solutions in the field of fault tolerance in real-time applications amongst which Cooperative Adaptive Cruise Control (CACC). This control system cannot rely on the driver as a backup and is constantly active and therefore more prominent to the occurrences of faults (such as packet loss in the wireless communication). This paper presents an algorithm which uses the availability of sensor-data in each moment in time to calculate in real-time a safe distance for the CACC system. This safe distance consists of a velocity dependent part and a constant part, both important settings in the spacing policy for the CACC. A critical scenario for which CACC should still be functional is chosen, mathematical models of the system response are derived and errors are modeled. The model enables the calculation of differences in braking distances, which leads to a required safe distance. This approach makes the dynamic algorithm useful for sensor faults. The algorithm is implemented in a test vehicle and test results are presented. © 2013 IEEE.

The possibility of growing multicomponent oxides by spatial atmospheric atomic layer deposition has been investigated. To this end, Al xZn1-xO films have been deposited using diethyl zinc (DEZ), trimethyl aluminum (TMA), and water as Zn, Al, and O precursors, respectively. When the metal precursors (i.e., TMA and DEZ) are coinjected in the deposition region, the Al/(Al + Zn) ratio can be accurately controlled by either varying the TMA flow to the reactor or the exposure time of the substrate to the precursors. A high doping efficiency level (up to 70%) is achieved in Al-doped ZnO, resulting in films with a high carrier density (5 × 10 20 cm-3), low resistivity (2 × 10-3 Ω cm), and good optical transparency (>85%) in the visible range. The morphology of the films changes from polycrystalline, in conductive i-ZnO and Al-doped ZnO, to amorphous, in highly resistive Al-rich films. The unique combination of the fine tuning of the composition, morphology, and electrical properties of the films with high deposition rates (>0.2 nm/s) paves the way for spatial ALD as an emerging disruptive technique for the growth of multicomponent oxides over large areas. © 2013 American Chemical Society.

Lighting is an advancing phenomenon both on the technology and on the market level due to the rapid development of the solid-state lighting technology. The interest in solder joint reliability has increased by the introduction of the so-called high brightness leadless type of packages. Solder joint reliability is one of the main failure modes in these package types, especially when it comes down to lifetimes beyond 20,000 h. Many end customers require lifetime prediction data with respect to board-level reliability. As it is time consuming to determine the endurance performance of each package separately, we have to look for means to reduce test time. A possible method is to actually determine the lifetime of a few products within one product family, and use the obtained results to verify and improve advanced simulation-based prediction models. The improved models will subsequently be used to predict the reliability performance of the entire product family in question. A new and innovative approach to accurately predict the boardlevel performance of LED packages is proposed.

Structured lead zirconium titanate (PZT)-epoxy composites are prepared by dielectrophoresis. The piezoelectric and dielectric properties of the composites as a function of PZT volume fraction are investigated and compared with the corresponding unstructured composites. The effect of poling voltage on piezoelectric properties of the composites is studied for various volume fractions of PZT composites. The experimentally observed piezoelectric and dielectric properties have been compared with theoretical models. Dielectrophoretically structured composites exhibit higher piezoelectric voltage coefficients compared to 0-3 composites. Structured composites with 0.1 volume fraction of PZT have the highest piezoelectric voltage coefficient. The flexural strength and bending modulus of the structured and random composites were analyzed using three-point bending tests. Copyright © Materials Research Society 2013.

A model describing the lateral dynamic behaviour of a web between and on rollers is implemented to aid in the design of roll to roll equipment. The model is validated on an industrial setup, and disturbances acting on the web were estimated. The model equations were used to visualise the interdependence between the span length and the disturbances allowed. This resulted in a span length that was least sensitive to disturbances.

Systems-in-foil technologies address the current need to manufacture low-cost, low-complexity and high-reliabiltiy large area organic electronics in the field of OLEDs, OPVs and sensors. For substrates with multiple layers of conductive tracks, there is a need to realize contact positions on either side of the foil. Unfortunately, typical interconnection solutions such as electroplating used in the PCB industry, are not highly compatible with large area electronics processing technologies, such as roll-to-roll processing. In this paper, the authors present results on the development of a reliable front-to-backside interconnection technology by filling laser drilled through vias (TVs) in PEN foil with a silver-based conductive adhesive using optimized stencil printing methods. Typical initial resistances for 100 μm TVs are situated in a range of 0.4 to 0.5 and TVs in a range of 0.15 to 0.35 for 200 μm, respectively. Samples were subjected to various accelerated life time tests; 1,000 hours at 60̊C/90%RH, 1,000 hours at 85̊C/85% RH, 1,000 cycles at -40̊C/120̊C and 15,000 bending cycles using cylinders with 10 mm and 25 mm bending radius. Only the bending stress resulted in an increase in via resistance. Stress during bending was simulated using FE modeling and maximum stress positions were compared to SEM cross sections of the vias. To emphasize the robustness of this interconnection technology, a flexible demonstrator was successfully fabricated consisting of a 10 by 10 grid of LEDs on the front side, connected to photo diodes on the backside of the foil using 200 μm TVs for interconnection. © 2013 IMAPS.

Within this work we present n-type self-assembled monolayer field-effect transistors (SAMFETs) based on a novel perylene bisimide. The molecule spontaneously forms a covalently fixed monolayer on top of an aluminium oxide dielectric via a phosphonic acid anchor group. Detailed studies revealed an amorphous, two-dimensional semiconducting sheet on top of the dielectric. Reliable transistors with electron mobilities on the order of 10-3 cm2/V s with limited hysteresis were achieved on rigid as well on flexible substrates. Furthermore, a flexible NMOS-bias inverter based on SAMFETs is demonstrated for the first time. (c) 2013 Elsevier B.V. All rights reserved.

The optical beam deflection (OBD) technique is used in many Atomic Force Microscopes to measure the motion of a cantilever as it probes the scanned surface. From the measured rotation, surface and sub-surface properties of the sample can be deduced. To maximize the sensitivity of the measurement, the combination of laser and cantilever should be aligned such that the laser impinges on the cantilever as close to its end tip as possible. Table-top AFM systems often use manual alignment. For industrial applications automatic alignment is necessary. This paper describes a method to automate this alignment procedure, using a laser induced thermo-mechanical response to actively bend the cantilever. This method also has applications in the characterization of bi-material cantilevers in a non-contact and non-destructive manner. The details of this characterization and the mathematical derivation are published elsewhere.

The main driver for Semiconductor and Bio-MEMS industries is decreasing the feature size, moving from the current state-of-the-art at 22 nm towards 10 nm node. Consequently smaller defects and particles become problematic due to size and number, thus inspecting and characterizing them are very challenging. Existing industrial metrology and inspection methods cannot fulfil the requirements for these smaller features. Scanning probe Microscopy (SPM) has the distinct advantage of being able to discern the atomic structure of the substrate. It can image the 3D topography, but also a variety of material, mechanical and chemical properties. Therefore SPM has been suggested as one of the technologies that can fulfil the future requirements in terms of resolution and accuracy, while being capable of resolving 3D futures. However, the throughput of the current state-of-the-art SPMs are extremely low, as compared to the high-volume manufacturing requirements. This paper presents the development of an architecture[1] for a fully automated high throughput SPM, which can meet the requirements of future process metrology and inspection for 450 mm wafers. The targeted specifications of the concept are 1) inspecting more than 20 sites per wafer, 2) each site with dimension of about 10 × 10 μm2 (scalable to 100 × 100 μm2) and 3) with a throughput of more than 7 wafers per hour, or 70 wafers per hour with a coarse/fine scanning approach. The progress of the high throughput SPM development is discussed and the baseline design of the critical sub-modules and the research issues are presented. © 2013 SPIE.

Carbon nanotube assemblies can be used for specific applications such as sensors and filters. We present a method and proof-of-concept to directly grow vertically-aligned carbon nanotube structures within sealed enclosures by means of a feedback-controlled laser-assisted chemical vapor deposition technique. The process is compatible with a variety of micro-fabrication processes and bypasses the need for post-process packaging. Our experiments raise interesting observations related to the gas diffusion dynamics in micro-scale and sub-micron enclosures.

Porous concrete is used as a construction material in various applications mainly as a permeable cementitious material. However, its response under impact loading is generally not considered. Due to the high percentage of its intentional meso-size air pores, porous concrete has a moderate static strength compared to normal concrete while its dynamic performance is distinctive. Owing to its characteristic of forming multiple cracks, it fractures into small fragments when exposed to impact loading. Therefore, with the aim of designing a special type of concrete to be used in protective structures, porous concrete was investigated. In this study, the impact strengths of different types of porous concretes were analyzed in correlation with their mixture compositions and production technique. The dynamic experiments were performed using a drop weight impact test set-up while the measurements were taken through Laser Doppler velocimetry. According to the results obtained, the aggregate properties and compactive effort, which are coupled to porosity, are the main factors that affect the dynamic performance of porous concrete. © 2013 Elsevier Ltd. All rights reserved.

The trade-off between transparency and conductivity in transparent conductors used in optoelectronic devices is a major bottleneck towards higher device performances. Grid deposition on transparent conductive oxides was demonstrated using electrochemical deposition, which has the advantage of a high aspect ratio of 0.45 and the possibility to use very narrow lines. The sheet conductivity was increased more than two orders of magnitude at a transmittance loss of only a fewpercent. The figure of merit as defined by Haackewas improved with a factor of more than 50. © 2013 Elsevier B.V. All rights reserved.

Het werkterrein van TNO is aanzienlijk breder dan de tuinbouw alleen. Maar onderzoek in 'vreemde sectoren' levert geregeld inzichten op die wel weer bruikbaar zijn voor toepassingen in de teelt van groenten, bloemen en planten. In elke editie van GTT Magazine reikt TNO een voorbeeld aan. Dit keer een uitstapje naar de LED-verlichting.