South African Journal of Industrial Engineering
versão On-line ISSN 2224-7890
versão impressa ISSN 1012-277X
MATOPE, S.; VAN DER MERWE, A.F. e RABINOVICH, Y.I.. Micro-material handling, employing e-beam coatings of copper and silver. S. Afr. J. Ind. Eng. [online]. 2012, vol.23, n.1, pp.114-121. ISSN 2224-7890.
Van der Waals forces and other adhesive forces impose great challenges on micro-material handling. Mechanical grippers fail to release micro-parts reliably because of them. This paper explores how the problematic Van der Waals forces may be used for micro-material handling purposes using surface roughnesses generated by e-beam coatings of copper and silver on silicon. An atomic force microscope, model Asylum MFP 3 D-Bio with version 6.22A software, was used to measure the forces exerted by the surfaces. A silver coating of 1.41 nm rms surface roughness value is found to exert the highest Van der Waals force, followed by a copper coating of 2.72 nm rms; a copper coating of 217 nm rms exerts the least force. This implies that, in a reliable micro-material handling system, these coatings are suitable for the interactive surfaces of the placement position, micro-gripper, and the pick-up position respectively.