Harry Heinzelmann
Swiss Center for Electronics and Microtechnology
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Harry Heinzelmann.
Applied Physics A | 1994
Harry Heinzelmann; Dieter W. Pohl
Scanning Near-field Optical Microscopy (SNOM) allows the investigation of optical properties on subwavelength scales. During the past few years, more and more attention has been given to this technique that shows enormous potential for imaging, sensing and modification at near-molecular resolution. This article describes the technique and reviews recent progress in the field.
Nano Letters | 2009
André Meister; Michael Gabi; Pascal Behr; Philipp Studer; Janos Vörös; Philippe Niedermann; Joanna Bitterli; Jérôme Polesel-Maris; Martha Liley; Harry Heinzelmann; Tomaso Zambelli
We describe the fluidFM, an atomic force microscope (AFM) based on hollow cantilevers for local liquid dispensing and stimulation of single living cells under physiological conditions. A nanofluidic channel in the cantilever allows soluble molecules to be dispensed through a submicrometer aperture in the AFM tip. The sensitive AFM force feedback allows controlled approach of the tip to a sample for extremely local modification of surfaces in liquid environments. It also allows reliable discrimination between gentle contact with a cell membrane or its perforation. Using these two procedures, dyes have been introduced into individual living cells and even selected subcellular structures of these cells. The universality and versatility of the fluidFM will stimulate original experiments at the submicrometer scale not only in biology but also in physics, chemistry, and material science.
Materials Today | 2006
Sivashankar Krishnamoorthy; Christian Hinderling; Harry Heinzelmann
The self-assembly processes of block copolymers offer interesting strategies to create patterns on nanometer length scales. The polymeric constituents, substrate surface properties, and experimental conditions all offer parameters that allow the control and optimization of pattern formation for specific applications. We review how such patterns can be obtained and discuss some potential applications using these patterns as (polymeric) nanostructures or templates, e.g. for nanoparticle assembly. The method offers interesting possibilities in combination with existing high-resolution lithography methods, and could become of particular interest in microtechnology and biosensing.
Applied Physics Letters | 2004
André Meister; Martha Liley; Jürgen Brugger; Raphaël Pugin; Harry Heinzelmann
In this letter, we describe the on-demand dispensing of single liquid droplets with volumes down to a few attoliters and submicrometric spacing. This dispensing is achieved using a standard atomic force microscope probe, with a 200 nm aperture at the tip apex, opened by focused ion beam milling. The inside of the tip is used as reservoir for the liquid. This maskless dispensing, realized in ambient environment, permits the direct creation of droplet arrays. Nanoparticles, suspended in the liquid, were organized on a surface.
Applied Physics Letters | 2000
R. Eckert; J. M. Freyland; Henkjan Gersen; Harry Heinzelmann; G. Schürmann; W. Noell; U. Staufer; N.F. de Rooij
High-resolution near-field optical imaging with microfabricated probes is demonstrated. The probes are made from solid quartz tips fabricated at the end of silicon cantilevers and covered with a 60-nm-thick aluminum film. Transmission electron micrographs indicate a continuous aluminum layer at the tip apex. A specially designed instrument combines the advantages of near-field optical and beam-deflection force microscopy. Near-field optical data of latex bead projection patterns in transmission and of single fluorophores have been obtained in constant-height imaging mode. An artifact-free optical resolution of 31.7±3.6 nm has been deduced from full width at half maximum values of single molecule images.
Ferroelectrics | 1999
L. Eng; M. Bammerlin; Ch. Loppacher; M. Guggisberg; Roland Bennewitz; R. Lüthi; Ernst Meyer; Thomas Huser; Harry Heinzelmann; H.-J. Güntherodt
Domain writing and reading on the nanometer scale is addressed with scanning force microscopy (SFM) Compared to other scanning probe methods, SFM provides broad possibilities for the on-line data controlling. i.e. three-dimensional mapping of polarisation distribution, differentiation between polarisation and topography, nanoscale domain switching of domains with a 60 nm diameter, recording of nanoscale hysteresis loops, phase transition mapping. domain wall imaging with 9 nm resolution, atomic resolution of ferroelectric surfaces, etc. All these issues are reported in this paper. The challenging result of such a concerted investigation is the possibility of using SFM for nanoscale domain writing and reading with nanometer resolution. Fig. 1 illustrates such an example where line shaped c - domains are purposely written into a ferroelectric Barium-Titanate single crystal with a 400 nm line-width. With this figure we highly appreciate and honour the work of Bob Newnham passing our best nano-wishes for his future.
Microelectronic Engineering | 2003
André Meister; S. Jeney; Martha Liley; T. Akiyama; U. Staufer; N.F. de Rooij; Harry Heinzelmann
Nanoscale dispensing is a novel technique to deposit material and create structures at dimensions of 100 nm and below. It has great flexibility in feature shape and choice of deposited material. Due to its potential low cost and lack of time consuming steps, it represents an interesting complementary tool to standard lithographic processes. The key feature of nanodispensing is deposition of liquids through an apertured scanning force microscopy probe tip. In the first experiments, liquid is manually loaded into a hollow pyramidal probe tip. Upon contact of the tip and the substrate, liquid at the end of the tip is transferred to the substrate surface. Moving the sample during contact allows to write features with sizes that can be as small as 100 nm and below, largely dependent on the aperture diameter. This approach is novel, and has recently been demonstrated in our laboratory for the first time, with feature sizes still well above 1 µm.
Journal of Molecular Recognition | 2011
Mélanie Favre; Jérôme Polesel-Maris; Thomas Overstolz; Philippe Niedermann; Stéphan Dasen; Gabriel Gruener; Réal Ischer; Peter Vettiger; Martha Liley; Harry Heinzelmann; André Meister
Atomic force microscopy (AFM) investigations of living cells provide new information in both biology and medicine. However, slow cell dynamics and the need for statistically significant sample sizes mean that data collection can be an extremely lengthy process. We address this problem by parallelizing AFM experiments using a two‐dimensional cantilever array, instead of a single cantilever. We have developed an instrument able to operate a two‐dimensional cantilever array, to perform topographical and mechanical investigations in both air and liquid. Deflection readout for all cantilevers of the probe array is performed in parallel and online by interferometry. Probe arrays were microfabricated in silicon nitride. Proof‐of‐concept has been demonstrated by analyzing the topography of hard surfaces and fixed cells in parallel, and by performing parallel force spectroscopy on living cells. These results open new research opportunities in cell biology by measuring the adhesion and elastic properties of a large number of cells. Both properties are essential parameters for research in metastatic cancer development. Copyright
European Physical Journal B | 1990
Ernst Meyer; Harry Heinzelmann; H. Rudin; H.-J. Güntherodt
The first atomically resolved atomic force microscopy images of the LiF (001) surface are presented. A square lattice with a spacing of 2.8±0.1 Å is resolved, which can be attributed to the F− ions. Li+ is not resolved due to its small size. The origin of the image contrast is discussed briefly and the results are compared with those from helium scattering.
Nanomedicine: Nanotechnology, Biology and Medicine | 2014
Gilles Weder; Mariëlle C. Hendriks-Balk; Rita Smajda; Donata Rimoldi; Martha Liley; Harry Heinzelmann; André Meister; Agnese Mariotti
UNLABELLED The stiffness of tumor cells varies during cancer progression. In particular, metastatic carcinoma cells analyzed by Atomic Force Microscopy (AFM) appear softer than non-invasive and normal cells. Here we examined by AFM how the stiffness of melanoma cells varies during progression from non-invasive Radial Growth Phase (RGP) to invasive Vertical Growth Phase (VGP) and to metastatic tumors. We show that transformation of melanocytes to RGP and to VGP cells is characterized by decreased cell stiffness. However, further progression to metastatic melanoma is accompanied by increased cell stiffness and the acquisition of higher plasticity by tumor cells, which is manifested by their ability to greatly augment or reduce their stiffness in response to diverse adhesion conditions. We conclude that increased plasticity, rather than decreased stiffness as suggested for other tumor types, is a marker of melanoma malignancy. These findings advise caution about the potential use of AFM for melanoma diagnosis. FROM THE CLINICAL EDITOR This study investigates the changes to cellular stiffness in metastatic melanoma cells examined via atomic force microscopy. The results demonstrate that increased plasticity is a marker of melanoma malignancy, as opposed to decreased stiffness.