A5062253644- Force Microscopy Techniques and Applications
- Mechanical and Optical Resonators
- Near-Field Optical Microscopy
- Molecular Junctions and Nanostructures
- Advanced Electron Microscopy Techniques and Applications
- Advanced Fluorescence Microscopy Techniques
- Integrated Circuits and Semiconductor Failure Analysis
- Piezoelectric Actuators and Control
- Graphene research and applications
- Nanofabrication and Lithography Techniques
- Microfluidic and Bio-sensing Technologies
- Surface and Thin Film Phenomena
- Robot Manipulation and Learning
- Gold and Silver Nanoparticles Synthesis and Applications
- Thermal properties of materials
- Electrochemical sensors and biosensors
- Carbon Nanotubes in Composites
- Electrowetting and Microfluidic Technologies
- Robotic Mechanisms and Dynamics
- Polymer Surface Interaction Studies
- Thermal Radiation and Cooling Technologies
- Space Satellite Systems and Control
- Electrochemical Analysis and Applications
- Quantum Dots Synthesis And Properties
- Flexible and Reconfigurable Manufacturing Systems
ETH Zurich
2015-2024
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2006-2024
École Polytechnique Fédérale de Lausanne
1999-2014
University of Zurich
2013
University of Bern
2013
IBM Research - Zurich
2006-2013
Institut für Mikroelektronik- und Mechatronik-Systeme
2010
Marine Biological Laboratory
1995-2008
University of Basel
1986-2004
Fritz Haber Institute of the Max Planck Society
1983
Purpose The paper seeks to present a new generation of torque‐controlled light‐weight robots (LWR) developed at the Institute Robotics and Mechatronics German Aerospace Center. Design/methodology/approach An integrated mechatronic design approach for LWR is presented. Owing partially unknown properties environment, robustness planning control with respect environmental variations crucial. Robustness achieved in this context through sensor redundancy passivity‐based control. In DLR root...
The combination of atomic force microscopy and Kelvin probe technology is a powerful tool to obtain high-resolution maps the surface potential distribution on conducting nonconducting samples. However, resolution contrast transfer this method have not been fully understood, so far. To better quantitative understanding, we introduce model which correlates measured with actual distribution, compare numerical simulations three-dimensional tip–specimen experimental data from test structures....
Sheets and rational synthesis are not like fire water! Hexafunctional terpyridine monomers can be laterally connected by metal salts to result in a mechanically stable, sheetlike entity that transferred from the air/water interface solid substrate (see folded, ca. 1.4 nm thin film) spanned over micrometer-sized holes. This is considered an important step on way 2D polymers. Detailed facts of importance specialist readers published as "Supporting Information". Such documents peer-reviewed,...
Abstract Imaging temperature fields at the nanoscale is a central challenge in various areas of science and technology. Nanoscopic hotspots, such as those observed integrated circuits or plasmonic nanostructures, can be used to modify local properties matter, govern physical processes, activate chemical reactions trigger biological mechanisms living organisms. The development high-resolution thermometry techniques essential for understanding thermal non-equilibrium processes during operation...
We identify the dynamics of an atomic force microscope (AFM) in order to design a feedback controller that enables faster image acquisition at reduced imaging error compared now generally employed proportional integral differential (PID) controllers. First, model for tip–sample interaction AFM is used show dynamic behavior cantilever working contact mode can be neglected control purposes due relatively small oscillation amplitude response defined topography step. Consequently, system...
During the last decade, various efforts have been undertaken to enhance resolution of optical microscopes, mostly because their importance in biological sciences. Herein, we describe a method increase fluorescence microscopy by illuminating specimen with mesh-like interference pattern laser source and electronic postprocessing images. We achieve 100-nm resolution, an improvement factor more than 2 compared standard 1.5 confocal scanning.
We discuss practical aspects of Kelvin probe force microscopy (KFM) which are important to obtain stable images the electric surface potential distribution at high spatial resolution (<100 nm) and sensitivity (<1 mV) on conducting nonconducting samples. compare metal-coated semiconducting tips with respect their suitability for KFM. Components metal coating can become detached during scanning, introducing sudden offset jumps in maps (typically up 350 mV between adjacent scan...
Fast and precise positioning is a basic requirement for nanotechnology applications. Many scanning-probe microscopes (SPM) use piezoelectric tube scanner actuation with nanometer resolution in all three spatial directions. Due to the dynamics of actuator, imaging speed SPM limited. By applying model-based open-loop control, dynamic behavior can be compensated, reducing displacement error, topographical artifacts, modulation interaction force, relative tip-sample velocity. The controlled...
Covalent monolayer sheets in 2 hours: spreading of threefold anthracene-equipped shape-persistent and amphiphilic monomers at the air/water interface followed by a short photochemical treatment provides access to infinitely sized, strictly monolayered, covalent with in-plane elastic modulus range 19 N/m. As service our authors readers, this journal supporting information supplied authors. Such materials are peer reviewed may be re-organized for online delivery, but not copy-edited or...
A method is described to quantify thermal conductance and temperature distributions with nanoscale resolution using scanning microscopy. In the first step, resistance of tip-surface contact measured for each point a surface. second local determined from difference between heat flux sources switched on off. The demonstrated self-heating silicon nanowires. While homogeneous nanowire shows bell-shaped profile, diode exhibits hot spot centered near junction two doped segments.
Nanoparticle superlattices produced with controllable interparticle gap distances down to the subnanometer range are of superior significance for applications in electronic and plasmonic devices as well optical metasurfaces. In this work, a method fabricate large-area (∼1 cm2) gold nanoparticle (GNP) typical size single domains at several micrometers high-density nanogaps tunable (from 2.3 0.1 nm) variable constituents organothiols inorganic S2-) is demonstrated. Our approach based on...
An advanced controller consisting of a feedback and feedforward part is presented to improve the performance an atomic force microscope (AFM) enabling topography measurements at higher scan rates with reduced measurement error. The tip–sample interaction held constant by -controller while scanner simultaneously tracked last recorded line model-based controller. designed implemented on commercial AFM system compare standard proportional integral controlled AFM. new reduces error enables...
In wide-field fluorescence microscopy, illuminating the specimen with evanescent standing waves increases lateral resolution more than twofold. We report a versatile setup for standing-wave illumination in total internal reflection microscopy. An adjustable diffraction grating written on phase-only spatial light modulator controls field. Selecting appropriate orders and displaying sheared (tilted) allows one to tune penetration depth very fine steps. The achieves 91 nm green emission.
Beyond the age of silicon: A combination radical chemistry under standard conditions and clean-room lithography can alter electronic structure graphene layers permanently through covalent chemical functionalization. The potential change follows Hammett correlation. This simple method is a promising approach for graphene-based electronics.
Oligofunctional terpyridine‐based monomers are spread at an air/water interface, where they connected with transition metal salts such as Fe(II) into mechanically coherent monolayer sheets of macroscopic dimension. The conversions these processes determined by XPS for several monomer/metal ion combinations. transferred onto TEM grids, the 20 × square micrometer sized holes which can be spanned. AFM indentation experiments provide in‐plane elastic moduli compared naturally occurring graphene....
Superior thermal conductivity of graphene is frequently reported and used to justify its technical relevance for ultimately scaled devices. However, this extraordinary property size dependent, understanding graphene's properties in the quasiballistic transport regime lacking. To overcome limitation, we directly probe local heat transfer into by high-resolution scanning microscopy on amorphous silicon oxide (SiO2) crystalline carbide (SiC). We quantify thickness-dependent resistance...
A conductive atomic force microscope (AFM) tip acts as a nanopencilto write positive or negative charge patterns into fluorocarbon film. Silica nanobeads (with surface charge) can be attached to by Coulombic interaction. While the resolution of writing process is up 100 nm, coagulation silica beads makes 1 μm realistic minimum width for structures thus formed (see Figure and also cover).
We demonstrate a low-cost, electrically tunable diffraction grating that is driven by dielectric elastomer actuator. The angular tuning range of the polymer-based device up to 118 mrad for first diffracted order. achievable period change 32% an improvement more than factor 150 compared with existing analog gratings based on hard materials. show in combination white light source, presented can be used as wavelength-adjustable luminous source. Such illuminant has potential application...
The dynamics of the microcantilever in atomic force microscopy (AFM) is represented by a multiple-degrees-of-freedom state-space model and discussed within framework system theory. cantilever modeled as linear time-invariant with nonlinear output feedback due to tip-sample interaction. This allows one use same analyze different aspects such contact-mode or tapping-mode AFM. approach dynamic response AFM for numerically efficient simulations. We show that not only eigenfrequency but also...
Atomic force microscopy on polymer surfaces is commonly carried out in the repulsive amplitude modulation mode (tapping mode). In order to achieve an additional measurement of electrostatic quantities under ambient conditions a higher flexural eigenmode used for electrical characterization surface during imaging. The resonantly excited by small ac-bias voltage between tip and sample. Thus, topography electric potential are measured simultaneously this multifrequency method. However, strong...
Hexafunktionelle Terpyridinmonomere können lateral durch Metallsalze verbunden werden, was zu einem mechanisch stabilen, blattähnlichen Gebilde führt, das von der Luft-Wasser-Grenzfläche auf einen festen Träger überführt (siehe den gefalteten, ca. 1.4 nm dünnen Film) und über μm-große Löcher gespannt werden kann. Dieser Befund ist ein wichtiger Schritt dem Weg hin zweidimensionalen Polymeren. Detailed facts of importance to specialist readers are published as "Supporting Information". Such...
We demonstrate frequency modulation Kelvin probe force microscopy operated in lift-mode under ambient conditions. Frequency detection is sensitive to gradients rather than forces as the commonly used amplitude technique. As a result there less influence from electric fields originating tip's cone and cantilever, recorded surface potential does not suffer large lateral averaging observed modulated microscopy. The technique further shows reduced dependence on lift-height shift can be map...