Self-healing of bitumen is a property that positively contributes to the sustainability, maintenance requirements and cost effectiveness of asphalt pavements. Ideally one would like to design an asphalt mix with a well-defined healing potential. Although substantial research efforts have been dedicated to the healing mechanism in bitumen, complete understanding of the fundamental mechanisms that govern the property of healing is still lacking. Here we investigate the manifestation of damage and healing of bitumen at the microstructural level. Three distinct bitumen grades are subjected to mechanical loading conditions, and the damage is investigated at the microstructural level by atomic force microscopy combined with finite element simulations. One of the bituminous phases appears to display visible signs of cracks, which are found to (partly) disappear at moderate temperature changes. Simulations of mechanical loading of experimentally derived finite element meshes are corresponding well with these experimental observations. Moreover, the simulations provide a measure of mechanical response, i.e. stiffness, of the material as a function of strain level. From this it is found that the microstructural cracks lead to diminished structural response properties, whereas after healing these properties are partly recovered. The experimental observations, together with the simulations, support earlier ideas that relate the phenomenon of self-healing in bitumen to their rheological property of thixotropy. Moreover, the work presented hints that the property of self-healing is governed by processes at the microstructural length scale.@en

High control performance i essential in manu precision positioning applications, such as control of the vertical sample position in a atomic-force microscope (AFM). This paper investigates the impact of load flexibility on piexoelectrically actuated positioning systems in terms of control performance. The modeling method used combines model analysis with simple transfer function manipulations, and shows, how the load dynamics may influence the ocntrol performance. The analysis is experimentally verified on a commercial AFM system.@en

High control performance i essential in manu precision positioning applications, such as control of the vertical sample position in a atomic-force microscope (AFM). This paper investigates the impact of load flexibility on piexoelectrically actuated positioning systems in terms of control performance. The modeling method used combines model analysis with simple transfer function manipulations, and shows, how the load dynamics may influence the ocntrol performance. The analysis is experimentally verified on a commercial AFM system.@en

High control performance i essential in manu precision positioning applications, such as control of the vertical sample position in a atomic-force microscope (AFM). This paper investigates the impact of load flexibility on piexoelectrically actuated positioning systems in terms of control performance. The modeling method used combines model analysis with simple transfer function manipulations, and shows, how the load dynamics may influence the ocntrol performance. The analysis is experimentally verified on a commercial AFM system.@en

High control performance i essential in manu precision positioning applications, such as control of the vertical sample position in a atomic-force microscope (AFM). This paper investigates the impact of load flexibility on piexoelectrically actuated positioning systems in terms of control performance. The modeling method used combines model analysis with simple transfer function manipulations, and shows, how the load dynamics may influence the ocntrol performance. The analysis is experimentally verified on a commercial AFM system.@en

Piezoelectric tube scanners are commonly used in Scanning Probe Microscopy (SPM) to provide the scanning motion of the tip or sample. Oscillations due to the weakly damped resonances of the scanner are a major souce of image distortion in SPM-imaging. In this contribution, multiple input-multiple output (MIMO) self-sensing actuation of a piezoelectric tube scanner is presented, allowing to actively dampen the scanner oscillation. By connecting the tube scanner in a capacitive bridge-circuit, the piezoelectric tube is simultaneously used as a sensor and actuator. In order to enable the use of low-order decentralized controllers, the cross-talk between both axes is reduced by compensating for the capacitive coupling. The MIMO self-sensing actuation allows to actively dampen the scanners's fundamentsl resonance by 18dB, which simultaneously reducing the resonance induced coupling by 30dB. Experimental results verify a significant reduction of the scanner oscillations in both positioning axes during fast scanning.@en

Mechanical vibrations occuring in a production environment cause a relative motion between the sample and inspection tool that distorts measurements at the nanometer level. To overcome this problem, this paper proposes a metrology platform that maintains a constant relative distance to the sample by means of an H& inf;-feedback controller. Experiments in one degree of freedom show that the metrology platform can reduce vibrations as they occur in a production environment by one order of magnitude. Therefore, it enables in-line surface metrology at the nanometer level.@en

Mechanical vibrations occuring in a production environment cause a relative motion between the sample and inspection tool that distorts measurements at the nanometer level. To overcome this problem, this paper proposes a metrology platform that maintains a constant relative distance to the sample by means of an H& inf;-feedback controller. Experiments in one degree of freedom show that the metrology platform can reduce vibrations as they occur in a production environment by one order of magnitude. Therefore, it enables in-line surface metrology at the nanometer level.@en

Mechanical vibrations occuring in a production environment cause a relative motion between the sample and inspection tool that distorts measurements at the nanometer level. To overcome this problem, this paper proposes a metrology platform that maintains a constant relative distance to the sample by means of an H& inf;-feedback controller. Experiments in one degree of freedom show that the metrology platform can reduce vibrations as they occur in a production environment by one order of magnitude. Therefore, it enables in-line surface metrology at the nanometer level.@en

Mechanical vibrations occuring in a production environment cause a relative motion between the sample and inspection tool that distorts measurements at the nanometer level. To overcome this problem, this paper proposes a metrology platform that maintains a constant relative distance to the sample by means of an H& inf;-feedback controller. Experiments in one degree of freedom show that the metrology platform can reduce vibrations as they occur in a production environment by one order of magnitude. Therefore, it enables in-line surface metrology at the nanometer level.@en

Since they entered our world around the middle of the 20th century, the application of mechatronics has enhanced our lives with functionality based on the integration of electronics, control systems and electric drives. This book deals with the special class of mechatronics that has enabled the exceptional levels of accuracy and speed of high-tech equipment applied in the semiconductor industry, realising the continuous shrink in detailing of micro-electronics and MEMS. As well as the more frequently presented standard subjects of dynamics, motion control, electronics and electromechanics, this book includes an overview of systems engineering, optics and precision measurement systems, in an attempt to establish a connection between these fields under one umbrella.@en

Since they entered our world around the middle of the 20th century, the application of mechatronics has enhanced our lives with functionality based on the integration of electronics, control systems and electric drives. This book deals with the special class of mechatronics that has enabled the exceptional levels of accuracy and speed of high-tech equipment applied in the semiconductor industry, realising the continuous shrink in detailing of micro-electronics and MEMS. As well as the more frequently presented standard subjects of dynamics, motion control, electronics and electromechanics, this book includes an overview of systems engineering, optics and precision measurement systems, in an attempt to establish a connection between these fields under one umbrella.@en

Since they entered our world around the middle of the 20th century, the application of mechatronics has enhanced our lives with functionality based on the integration of electronics, control systems and electric drives. This book deals with the special class of mechatronics that has enabled the exceptional levels of accuracy and speed of high-tech equipment applied in the semiconductor industry, realising the continuous shrink in detailing of micro-electronics and MEMS. As well as the more frequently presented standard subjects of dynamics, motion control, electronics and electromechanics, this book includes an overview of systems engineering, optics and precision measurement systems, in an attempt to establish a connection between these fields under one umbrella.@en

Measuring properties at the nanometre scale such as topography, morphology and roughness within a production line becomes increasingly important for quality control and process monitoring tasks. In a production line, ground vibrations are transmitted to the sample and the inspection tool, corrupting nanoscale measurements by affecting the distance between inspection tool and sample. To enable nanometre scale measurements a mechanism is needed that keeps this distance constant. This paper describes the concept and experimental results of a metrology platform that tracks the sample for nanoscale inspection. The nano inspection tool is carried by the metrology platform and is artificially coupled to the movement of the sample by using a feedback controller. A one degree of freedom experimental setup was built for demonstrating tracking performance. The implemented closed loop control achieves disturbance rejection with a bandwidth of 410 Hz and reduces emulated on-site vibrations from ±500 nm down to ±9 nm, showing significant reduction of external vibrations.@en

Measuring properties at the nanometre scale such as topography, morphology and roughness within a production line becomes increasingly important for quality control and process monitoring tasks. In a production line, ground vibrations are transmitted to the sample and the inspection tool, corrupting nanoscale measurements by affecting the distance between inspection tool and sample. To enable nanometre scale measurements a mechanism is needed that keeps this distance constant. This paper describes the concept and experimental results of a metrology platform that tracks the sample for nanoscale inspection. The nano inspection tool is carried by the metrology platform and is artificially coupled to the movement of the sample by using a feedback controller. A one degree of freedom experimental setup was built for demonstrating tracking performance. The implemented closed loop control achieves disturbance rejection with a bandwidth of 410 Hz and reduces emulated on-site vibrations from ±500 nm down to ±9 nm, showing significant reduction of external vibrations.@en

Measuring properties at the nanometre scale such as topography, morphology and roughness within a production line becomes increasingly important for quality control and process monitoring tasks. In a production line, ground vibrations are transmitted to the sample and the inspection tool, corrupting nanoscale measurements by affecting the distance between inspection tool and sample. To enable nanometre scale measurements a mechanism is needed that keeps this distance constant. This paper describes the concept and experimental results of a metrology platform that tracks the sample for nanoscale inspection. The nano inspection tool is carried by the metrology platform and is artificially coupled to the movement of the sample by using a feedback controller. A one degree of freedom experimental setup was built for demonstrating tracking performance. The implemented closed loop control achieves disturbance rejection with a bandwidth of 410 Hz and reduces emulated on-site vibrations from ±500 nm down to ±9 nm, showing significant reduction of external vibrations.@en

Measuring properties at the nanometre scale such as topography, morphology and roughness within a production line becomes increasingly important for quality control and process monitoring tasks. In a production line, ground vibrations are transmitted to the sample and the inspection tool, corrupting nanoscale measurements by affecting the distance between inspection tool and sample. To enable nanometre scale measurements a mechanism is needed that keeps this distance constant. This paper describes the concept and experimental results of a metrology platform that tracks the sample for nanoscale inspection. The nano inspection tool is carried by the metrology platform and is artificially coupled to the movement of the sample by using a feedback controller. A one degree of freedom experimental setup was built for demonstrating tracking performance. The implemented closed loop control achieves disturbance rejection with a bandwidth of 410 Hz and reduces emulated on-site vibrations from ±500 nm down to ±9 nm, showing significant reduction of external vibrations.@en

Piezoelectric tube scanners are typically used in atomic force microscopy (AFM) to prove the scanning motion of the sample. Excitation of the weakly damped fundamental resonance of the tube scanner leads to oscillations that can cause severe image distortion. This paper presents self-sensing actuation of a piezoelectric tube scanner in order to actively damp the fundamental resonance. By electrically connection the tube scanner in a capacitive bridge-circuit, the scanner oscillations can be measured without the need for expensive position sensors. In order to compensate for circuit imbalance caused by hysteresis an adaptation circuit is use. The obtained measurement signal is used for feedback control, adding 18dB of damping to the scanners fundamental resonant mode. AFM images are obtained showing a significant reduction in image distortion compared to the uncontrolled case.@en

Piezoelectric tube scanners are typically used in atomic force microscopy (AFM) to prove the scanning motion of the sample. Excitation of the weakly damped fundamental resonance of the tube scanner leads to oscillations that can cause severe image distortion. This paper presents self-sensing actuation of a piezoelectric tube scanner in order to actively damp the fundamental resonance. By electrically connection the tube scanner in a capacitive bridge-circuit, the scanner oscillations can be measured without the need for expensive position sensors. In order to compensate for circuit imbalance caused by hysteresis an adaptation circuit is use. The obtained measurement signal is used for feedback control, adding 18dB of damping to the scanners fundamental resonant mode. AFM images are obtained showing a significant reduction in image distortion compared to the uncontrolled case.@en

The macroscopic mechanical response properties of bituminous materials originate from the mechanical properties at the microstructural level. From atomic force microscopy (AFM) investigations, it is evident that mainly two material phases are present in bitumen; these phases can be loosely associated with bitumen's chemical composition (i.e., crude oil origin). However, little is known about the mechanical properties of the constituent phases of bitumen. In this research, an AFM technique was used to obtain mechanical property maps of two bitumens. This technique can distinguish between phases and provide quantitative results. The mechanical properties at the nano-to micrometer-length scale govern the overall properties of bitumen when considered as a microscale composite material. A mechanics approach is followed to derive the composite modulus from the individual phase properties. Furthermore, the temperature dependence of mechanical properties is determined on heating the bitumens from ambient conditions. With an increase in temperature, the moduli of both phases decrease, whereas the phases become more adhesive. The results demonstrate a successful quantitative characterization of the mechanical properties of bitumen microphases and the subsequent coarse graining of these properties into composite mechanical response properties. These mechanical properties (i.e., stiffness and adhesion potential) are important input parameters for material design and modeling and will allow one to predict the macroscopic behavior of asphalt concrete according to fundamental quantities. Finally, a better understanding of the temperature dependence of microstructural mechanical properties can contribute to the understanding of the thermorheological properties of bitumen for optimal processing conditions and best performance.@en