![]() ![]() Early spectroscopy experiments compared relative forces with high accuracy, for which the absolute stiffness of the sensor was not critical. Especially the precise knowledge of the sensor stiffness k qPlus is crucial for quantitative interpretation of force spectroscopy measurements. Quartz tuning fork force sensors in contrast are usually hand-made and even though they are commercially available, they are far from mass production and therefore exhibit a large spread of geometric – and thus of elastic parameters. Their spread in geometric parameters is within a low range and the characterization of their geometric parameters has been presented extensively by theory and experiments. ![]() Today, many commercially available AFMs for UHV and LT conditions are based on quartz sensors because of their impressive performance and easy technical implementation.Ĭommon AFM sensors are microfabricated from silicon or silicon nitride with the tip already integrated. For these conditions, force sensors based on quartz tuning forks in the “qPlus” design have been proven to routinely provide stable operation and sufficient sensitivity to achieve the highest resolution in nc-AFM experiments. ![]() nc-AFM experiments at the atomic scale usually demand well defined environments, such as ultrahigh vacuum (UHV) and low temperatures (LT). Recent achievements of this force spectroscopy method manifest in the identification of the chemical identity of single atoms in an alloy or the measurement of the force applied during the controlled manipulation of molecules or atoms on a surface. Furthermore, the non-contact AFM (nc-AFM) technique has the capability of quantifying the interaction forces acting between the probing tip and the sample site with atomic precision. We further found significant discrepancies between experimental calibration values and predictions from the shifted beam formula, which are related to a large variance in tip misalignment during the tuning fork assembling process.Ītomic force microscopy (AFM) allows the imaging of surfaces with true atomic resolution and the resolution of intra-molecular structures of molecules. The simulations show quantitative agreement with the beam formula if the beam origin is shifted to the position of zero stress onset inside the tuning fork base and torsional effects are also included. These simulations provide a detailed view of the strain/stress distribution inside the tuning fork. In order to understand this discrepancy the complete sensor set-up has been digitally rebuilt and analyzed by using finite element method simulations. The results show a significant deviation from values calculated with the beam formula. In this study a new and easily applicable setup has been used to determine the static spring constant at several positions along the prong of the tuning fork. By measuring the frequency shift, quantitative information of the analyte is obtained.Quartz tuning forks are being increasingly employed as sensors in non-contact atomic force microscopy especially in the “qPlus” design. As soon as an external force or an environmental change influences the tuning fork, the self-oscillation frequency changes. The Tuning Fork Sensor Controller excites the self-oscillation of quartz tuning-fork-based sensors at their resonance frequency. Quartz Tuning Forks are highly useful for various sensing applications such as Scanning Probe Microscopy (SPM), Atomic Force Microscopy (AFM), viscosity/vacuum measurements, Bio/chemical sensing, etc. The new NanoAndMore Tuning Fork Sensor Controller offers our customers the convenience of a ready to use electronic device to control and to measure the frequency of the NANOSENSORS™ Akiyama-Probe and other self-oscillating quartz tuning fork-based sensors without having to build the whole Akiyama-Probe set-up from scratch. The new NanoAndMore Tuning Fork Sensor Controller is an electronic device to control the self-oscillation of a quartz tuning fork based sensor and to measure its frequency. ![]()
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