Conceptual design of a microscale balance based on force compensation. - In: Microactuators, microsensors and micromechanisms, (2021), S. 103-114
Macroscopic electromagnetic force compensation (EMFC) balances are well established but were not yet demonstrated within microsystems. Hence, in this paper, the concept and the design of a micro fabricated force compensation balance is presented. The implemented concentrated compliance mechanism in form of flexure hinges enables motion with high precision, which is combined with a force compensation mechanism. The concept of force compensation promises a high measurement range, which is expected to be up to 0.5 mN, while still enabling a high resolution of less than 8 nN. The developed dynamic model of the miniaturized balance is used for the design of a PID-controller strategy. Here, continuous and time-discrete controller approaches are compared. The time-discrete controller with realistic delay times, leads to an accuracy of the controller, which is better than the expected accuracy of the integrated capacitive position sensor.
https://doi.org/10.1007/978-3-030-61652-6_9
Radius and roundness measurement of micro spheres based on a set of AFM surface scans. - In: Measurement science and technology, ISSN 1361-6501, Bd. 32 (2021), 4, 044005, S. 1-11
Micro coordinate measuring machines have been developed for the traceable characterisation of small complex parts, due to the demand in research and industry. These machines require geometrically well characterised probing spheres of ever smaller radii. Currently, there is no established procedure for the measurement of such spheres below radii of 500 [my]m. In this paper we, therefore, propose and investigate an approach which is based on a set of AFM surface scans in conjunction with a stitching algorithm. The strategy was implemented on a nano measuring machine and investigated on a ruby sphere with a radius of 150 [my]m. Although the strategy can generally be applied to the characterisation of a full sphere, we limit ourselves to the measurement of one greate circle (equator). The technique enables the measurement of micro spheres with a high lateral and vertical resolution. The mean radius of the ruby sphere was measured with a standard deviation of 3.7 nm over 6 repetitions. As our experiments have shown, the measurement procedure is at the moment mainly influenced by the shape of the AFM tip which requires further attention.
https://doi.org/10.1088/1361-6501/abcff4
Coordinate transformation and its uncertainty under consideration of a non-orthogonal coordinate base. - In: Measurement science and technology, ISSN 1361-6501, Bd. 32 (2021), 4, 045001, insges. 6 S.
Nanopositioning and nanomeasuring machines are 3D coordinate measuring systems with nanometer precision at measurement volumes in the cubic centimeter range. The coordinate base is formed by an interferometer system with a common mirror corner. The orthogonality deviations of the mirror corner require a coordinate transformation of the measuring axes. The uncertainty of the coordinate transformation must be taken into account in the overall measurement uncertainty budget. Starting from a complete transformation model, the result of model simplications on the transformation behaviour is analysed and discussed.
https://doi.org/10.1088/1361-6501/aba3f5
An electrothermally actuated membrane as oscillating pinhole for the high-frequent modulation of light. - In: DGaO-Proceedings, ISSN 1614-8436, Bd. 121 (2020), B37, insges. 2 S.
We present theory, processing steps and first results for a thermally actuated Aluminiumnitride-Platinum membrane with a resonant frequency of the first mode at around 100 kHz and resonant displacements at its center of around 30 µm. The radial-symmetric membrane is broadband opaque for wavelengths from visual light and beyond. An exception is a small pinhole of various diameters below 3 µm in its center. Through thermally induced asymmetric stress inside the multilayer, the clamped membrane bends out. The pinhole in its center will be displaced parallel to the optical axis.The intended use for such a membrane is to replace the traditional confocal pinhole in the detection path of a microscope. Applying a stable known resonant modulation on an acquired signal enables a lock-in principle for a differential confocal depth sensing as shown in [1]. The advantage over the employed tunable acoustic gradient lens (TAG lens) there, is the reduced size, the simplicity of the arrangement and constant illumination properties on the sample.
https://nbn-resolving.org/urn:nbn:de:0287-2020-B037-6
Grundlegende Untersuchungen zur Entwicklung von fünfachsigen Nanopositioniermaschinen für Mess- und Fertigungszwecke. - In: Jahrbuch Optik und Feinmechanik, ISSN 0075-272X, Bd. 66 (2020), S. 67-92
Selbstkalibrierende Präzisionswaagen für den industriellen Einsatz : Abschlussbericht Projekt VIP+ Planck-Waage : Berichtszeitraum: 01.01.2017-31.12.2019. - [Ilmenau] : [Technische Universität Ilmenau]. - 1 Online-Ressource (11 Seiten, 769,99 KB)Förderkennzeichen BMBF 03VP02851
https://doi.org/10.2314/KXP:1756259070
Generation of static and dynamic small calibration forces and their measurements by electromagnetic force compensation balance. - In: Acta IMEKO, ISSN 2221-870X, Bd. 9 (2020), 5, S. 113-117
The paper presents some of the results of the static and dynamic force measurements at 100 nN to sub-10 [my]N ranges which are generated due the photon-momentum. The force sensor with resolution about 20 nN and operating in differential measurement mode is developed by two electromagnetic force compensation balances. In order to generate these calibration forces, CW lasers with different operational modes, power levels, and wavelengths are used. Multi-reflection configuration of the laser beam inside the macroscopic cavity with highly reflective mirrors are used to test and variate the total amount of the forces.
https://doi.org/10.21014/acta_imeko.v9i5.951
Error sources in the force mode of the "PB2" Planck-Balance. - In: Acta IMEKO, ISSN 2221-870X, Bd. 9 (2020), 5, S. 53-57
The PB2 Planck-Balance is a table-top Kibble balance, that is designed for the calibration of class E2 weights in a range of 1 mg up to 100 g. This work presents typical systematic errors which have to be considered during the calibration and will show results for measurements with small masses.
https://doi.org/10.21014/acta_imeko.v9i5.938
Influences on amplitude estimation using three-parameter sine fitting algorithm in the velocity mode of the Planck-Balance. - In: Acta IMEKO, ISSN 2221-870X, Bd. 9 (2020), 3, S. 40-46
The Planck-Balance is a table-top version of a Kibble balance. In contrast to many other Kibble balances, the coil is moved sinusoidally and an ac rather than a dc signal is generated in the velocity mode. The three-parameter sine fitting algorithm is applied to estimate the amplitudes of the induced voltage and the coil motion, which are used to determine the force factor Bl of the voice coil of the electromagnetic force compensation balance. However, the three-parameter sine fitting algorithm is not robust against some perturbations, e.g. additive Gaussian white noise, quantization error, harmonic distortion, frequency error and time jitter. These effects have influences on the accuracy of the amplitude estimation. Based on numerical simulations and correlation analyses, the effects of these perturbations are determined. By optimizing measurement and data processing approach, the bias and standard deviation of the estimated amplitude can be effectively reduced, and thus the accuracy of the force factor Bl in the velocity mode can be improved.
https://doi.org/10.21014/acta_imeko.v9i3.781
Investigations on nonlinear deformation phenomena in a force calibration system. - In: Acta IMEKO, ISSN 2221-870X, Bd. 9 (2020), 5, S. 150-155
Previous investigations show, in force calibration and measurement systems that are based on electromagnetic force compensation (EMFC), deformations of the flexure hinges can cause significant contributions to the uncertainty of the system. A Simulink model of the Planck-Balance 2 (PB2) is established in MATLAB according to the CAD model. The results are compared to simplified analytical models and the results obtained from measurement.
https://doi.org/10.21014/acta_imeko.v9i5.958