Thomas Preisner, Christian Bolzmacher, Andreas Gerber, Karin Bauer, Eckhard Quandt and Wolfgang Mathis
The purpose of this paper is to investigate the accuracy of different force calculation methods and their impact on mechanical deformations. For this purpose, a micrometer scaled…
Abstract
Purpose
The purpose of this paper is to investigate the accuracy of different force calculation methods and their impact on mechanical deformations. For this purpose, a micrometer scaled actuator is considered, which consists of a micro‐coil and of a permanent magnet (PM) embedded in a deformable elastomeric layer.
Design/methodology/approach
For the magnetic field evaluation a hybrid numerical approach (finite element method/boundary element method (FEM/BEM) coupling and a FEM/BEM/Biot‐Savart approach) is used, whereas FEM is implemented for the mechanical deformation analysis. Furthermore, for the magneto‐mechanical coupling several force calculation methods, namely the Maxwell stress tensor, the virtual work approach and the equivalent magnetic sources methods, are considered and compared to each other and to laboratory measurements.
Findings
The numerically evaluated magnetic forces and the measured ones are in good accordance with each other with respect to the normal force acting on the PM. Nevertheless, depending on the used method the tangential force components differ from each other, which leads to slightly different mechanical deformations.
Research limitations/implications
Since the force calculations are compared to measurement data, it is possible to give a suggestion about their applicability. The mechanical behavior of the actuator due to the acting forces is solely calculated and therefore only an assumption concerning the deformation can be given.
Originality/value
A new kind of micrometer scaled actuator is numerically investigated by using two different hybrid approaches for the magnetic field evaluation. Based on those, the results of several force calculation methods are compared to measurement data. Furthermore, a subsequent structural analysis is performed, which shows slightly different mechanical deformations depending on the used force calculation method.
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Uzzal Binit Bala, Michael Greiff, Thomas Preisner and Wolfgang Mathis
The purpose of this paper is to present a hybrid numerical simulation approach for the calculation of potential and electric field distribution considering charge and dielectric…
Abstract
Purpose
The purpose of this paper is to present a hybrid numerical simulation approach for the calculation of potential and electric field distribution considering charge and dielectric constant.
Design/methodology/approach
Each numerical method has its own advantages and disadvantages. The idea is to overcome the disadvantages of the corresponding numerical method by coupling with other numerical methods. An augmented finite element method (FEM), linear FEM and boundary element method are used with an efficient coupling.
Findings
The simulation model of microstructured devices is not so simple. During the simulation various types of problems will occur. It is found that by using several numerical methods these problems can be overcome and the calculation can be performed efficiently.
Research limitations/implications
The present approach can be applied in 2D cases. But, in 3D cases the calculation of augmented FEM in a spherical coordinate becomes quite elaborate.
Practical implications
The proposed hybrid numerical simulation approach can be applied for the simulation of the electrostatic force microscope (EFM) which is a very high‐resolution measuring tool in nanotechnology. This approach can be applied also to other micro‐electro‐mechanical systems.
Originality/value
Since the scanning process of the EFM is dynamic, it requires the updating of the FEM mesh in each calculation time step. In the present paper, the mesh updating is achieved by an arbitrary Lagrangian‐Eulerian (ALE) method. The proposed numerical approach can be applied for the simulation of the EFM including this remeshing algorithm ALE.
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Thomas Preisner, Michael Greiff, Uzzal Binit Bala and Wolfgang Mathis
The purpose of this paper is to introduce a method which allows the calculation of the interactions of tip and sample of a magnetic force microscope as a first step to increase…
Abstract
Purpose
The purpose of this paper is to introduce a method which allows the calculation of the interactions of tip and sample of a magnetic force microscope as a first step to increase the accuracy of this technique.
Design/methodology/approach
The emerging magnetic interactions between the cantilever tip and an arbitrary magnetized sample can be evaluated by the use of several numerical methods. For modelling this magnetically and mechanically coupled multiscale problem the finite element method is implemented.
Findings
The evaluated magnetic fields interact in such a manner that a constructive overlap at the tip apex occurs. This leads to attractive forces acting on the cantilever.
Research limitations/implications
In order to include the magneto‐mechanical coupling, the implementation of a detailed force calculation is necessary. Furthermore, a hysteresis model is not yet considered.
Practical implications
Magnetic force microscopy is a very sensitive technique. For instance, ideally the end of the tip consists of only one atom, but this is not realizable. Measurement errors cannot be avoided. This approach is the first step in developing an opportunity to soften them.
Originality/value
One opportunity to verify real‐time magnetic force microscope measurements is the comparison with theoretical considerations and calculations of the occurring magnetic distribution by using this technique. For this reason this paper deals with a new micromagnetic model to simulate the interactions between tip and sample of a scanning process of a magnetic force microscope.
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The purpose is to conduct a systematic review of circular water management and its role in improving water availability amid increased demand and decreased supply.
Abstract
Purpose
The purpose is to conduct a systematic review of circular water management and its role in improving water availability amid increased demand and decreased supply.
Design/methodology/approach
A systematic literature review was implemented, which helped in the identification, selection and critical appraisal of the various research to answer the research question. It was guided by the Preferred Reporting Items for Systematic Reviews (PRISMA) statement. The review was conducted mainly on Web of Science and Scopus databases between November 20 and December 8, 2022, with search strategies involving free-text searching, phrase searching, truncation and Boolean operators.
Findings
The search process yielded 46 articles exploring circular water management. The findings reveal that circular water management offers more promise than linear or business-as-usual approaches. There are various circular water management models, although most of them emphasize a shift from the “take, make, consume and waste” principles. Contrarily, the success of the circular water management framework hinges on its ability to embrace resilience based on changing environmental conditions. Furthermore, the model focuses on improving inclusiveness with various stakeholders working together to improve water management.
Originality/value
The research is the first of its kind as it identifies a critical gap, the imperative need to develop a universal framework that can significantly advance the comprehension of circular water management.