Evaluation of adhesion forces between arbitrary objects for micromanipulation

This paper describes a numerical method to estimate adhesion forces that are present in different handling operations in the micro- and nanoworld. Emphasis is on the calculation of the van der Waals force, although the results can be generalized in a straightforward manner to also cover the electrostatic force. The presented method enables force calculation between objects that have arbitrary shapes and material properties together with arbitrary alignments relative to each other. The estimation accuracy is enhanced and the computational complexity is reduced by using surface formulation of the force instead of conventional volume formulation. The surface formulation also enables division of the surfaces into separate regions. This guarantees better accuracy in the computations and makes it possible to use only partial surfaces in the force evaluation.