Investigation of the AFM Contact-Mode Force Calibration with Simulation

Force-curves measured by Atomic Force Microscopy (AFM) are frequently used to determine the local Young’s Modulus of the sample. Originally the AFM (Atomic Force Microscopy) instruments measure the cantilever deflection as a voltage signal; however the natural unit of the deflection is nanometer. In general, the V/nm conversion factor is determined from the force-curve of a hard sample. Since this conversion is highly affects the value of the Young’s modulus, the accuracy of this method was investigated experimentally and using a finite element simulation of the cantilever motion. It was found, that the position of the laser spot significantly modify the conversion factor and in case of the sample with steep surface, the error of this calibration method can be significant

Coupled surface plasmon resonance on gold nanocubes - investigation by simulation

The refractive index sensitivity of coupled plasmonic nanostructures, namely gold nanocubes in various arrangements, were simulated with the MNPBEM Matlab toolbox. The size of the cubes, the distance between the particles were the running parameters. It was found that the enhancement factor (which characterize the increase in the peak shift for multi-particle arrangements compared to single-particle models) is an exponential function of (D/a) where D is the gap between the particles and a is the edge length of the cube. It was also found that significant plasmonic coupling effects starts below 0.5 D/a for cubical nanoparticles

Investigation of the Local Mechanical Properties of the SAC Solder Joint with AFM

Considering the size o f the natural appearance of the micro alloy components of a SAC solder joint, AFM was used to investigate their mechanical properties in the form of their natural appearance . C ontact - mode point - spectroscopy was done to determine the elastic modulus and tapping - mode point - spectroscopy was done to investigate the tip - sample power dissipation. The measured Young’s modulus values of the Cu , IML, Ag 3 Sn and Sn components , were 125±9 GPa, 111±20 GPa, 67±11 GPa and 57±16 GPa, respectively. The dissipation measurements were accomplished by Si and diamond probe s with different spring con stants. T he different characteristics of the results are dis cussed

Characterization of the shape of gold nanoparticles prepared by thermal annealing

Gold nanoparticles – which are intended to be used as transducers in a localized surface plasmon resonance (LSPR) sensor – were prepared by thermally annealing various layers of gold thin films deposited on glass substrate. The size and distribution of nanoparticles were investigated by atomic force microscopy (AFM). The changes in the nanoparticle shape in function of the deposition and annealing parameters are characterized. A novel parameter called localization factor was used to investigate the shape of the resulting particles. A common problem concerning the AFM imaging of nanoparticles, namely the tip convolution effect was studied, and possibilities to use the localization factor parameter to optimize surface reconstruction algorithms via tip deconvolution is demonstrated

Macro, Micro, and Nano Level Analysis of Cavitation Damage Mechanism in FCC Materials

The aim of this paper is to demonstrate the analysis of cavitation damage mechanism in FCC (Face Centered Cub ic ) materials , and to establish a possible application of the cavitation phenomenon as an efficient method to modify surface properties. Three FCC materials ( c opper, AlMg - alloy and stainless steel ( St.St.316 ) ) were subjected to high speed submerged cavitating jets under certain working conditions, for different time periods. The force generated by cavitation is employed to deform and to damage the surface in scales ranging from nano to micro and macro . The target surface s were investigated with various techniqu es. Results indicate that at short exposure times, the observed characteristic features in the microstructure – hills, holes and wavy configuration – can be related to the start of the plastic deformation of the specimen surface. By increasing the exposur e time , the surface s bec a me eroded, the damaged area is characterized by many rings , with different degrees of surface roughness . The results related to the early stage of cavitation damage demonstrate the possibility to us e cavitation bubbles as a micro/ n ano fabrication method for the surface preparation/modification or for example shoot - less surface peening

Investigation of PDMS-gold nanoparticle composite films for plasmonic sensors

Poly(dimethylsiloxane) (PDMS)–gold nanoparticle composite films were synthetized in situ by using a simple method based on the reduction of chloroauric acid (HAuCl4) by the PDMS membrane. The technological parameters which affect the gold nanoparticle formation on the membrane (namely the concentration of the HAuCl4 solution, the ratio of curing agent, the incubation time and the temperature) were investigated, the resulting nanoparticle films were characterized with optical spectrophotometry. The possibility to utilize the nanocomposite membranes as sensing elements in plasmonics sensors (based on localised surface plasmon resonance – LSPR) and as surface enhanced Raman spectroscopy (SERS) substrates is discussed in detail

LSPR nanosensors with highly ordered gold nanoparticles fabricated on nanodimpled aluminium templates

The fabrication and characterization of a localized surface plasmon resonance (LSPR) based optical nanosensor, which utilizes highly ordered gold nanoparticles as transducers are presented in this work. The nanoparticles are synthetized using nanodimpled aluminium templates, which were prepared by a selective chemical etching of the porous anodic alumina grown over an aluminium sheet. The formed nanoparticles were directly transferred to PDMS (polydimethylsiloxane) based microfluidic cells, where their LSPR transmittance spectra were measured. The effect of the particle size and distribution on the LSPR bulk refractive index sensitivity is investigate

A Review on Current eCall Systems for Autonomous Car Accident Detection

The aim of the paper is to give an overview on the existing eCall solutions for autonomous car accident detection. The requirements and expectations for such systems, considering both technological possibilities, legal regulatory criteria and market demands are discussed. Sensors utilized in e-call systems (crash sensing, systems for positional and velocity data, and communication solutions) are overviewed in the paper. Furthermore, the existing solutions for eCall devices are compared based on their level of autonomy, technical implementation and provided services