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South African Journal of Industrial Engineering

On-line version ISSN 2224-7890
Print version ISSN 1012-277X

S. Afr. J. Ind. Eng. vol.22 n.2 Pretoria  2011


Micro-material handling employing e-beam generated topographies of copper and aluminium



S. MatopeI; A.F. van der MerweII; R. NemutudiIII; M. NkosiIV; M. MaazaV

IDepartment of Industrial Engineering, University of Stellenbosch, South Africa,
IIDepartment of Industrial Engineering, University of Stellenbosch, South Africa,
IIIDepartment of Material Science, iThemba Labs, South Africa,
IVDepartment of Material Science, iThemba Labs, South Africa,
VDepartment of Material Science, iThemba Labs, South Africa,




This paper focuses on the employment of copper and aluminium in a micro-material handling system actuated by Van der Waals forces. Electron beam (e-beam) evaporator deposited both materials on a silicon substrate at a rate of 0.6-1.2 Angstroms/second, vacuum pressure between 2x10-6 and 3x10-6mbar, and at a current less than 10mA. A Veeco NanoMan V Atomic Force Microscope with Nanoscope version 7.3 software was used to analyse the root mean square (rms) surface roughnesses of the generated topographies. Rumpf-Rabinovich's rms formula was used to determine the Van der Waals forces exerted by the surfaces. It was synthesised that an e-beam deposition of 7 minutes' duration on both materials produced an optimum micro-material handling solution, with copper suitable for the pick-up position and aluminium for the placement position.


Die fokus van die artikel is op die gebruik van koper en aluminium in 'n mikromateriaalhanteringstelsel, aangedryf deur Van der Waalskragte. 'n Elektronstraal-verdamper plaas albei materiale op 'n silikonbasis teen 'n tempo van 0.6-1.2 Angstrom/sekonde, vakuumdruk tussen 2x10-6 en 3x10-6mbar, en teen 'n stroom van minder as 10mA. 'n Veeco NanoMan V Atomic Force mikroskoop, met Nanoscope 7.3 program-matuur is gebruik om die wortel-gemiddelde-kwadraat (wgk) oppervlak ruheid van die gegenereerde topografieë te analiseer. Rumpf-Rabinovich se wgk-formule is gebruik om die Van der Waalskrage wat deur die oppervlaktes uitgeoefen word te bepaal. Dit is vasgestel dat 'n elektronstraalafsetting van 7 minute op albei materiale die optimale materiaalhanteringoplossing bied, met koper geskik vir die optelposisie en aluminium vir die plasingsposisie.



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[1] Bergstrom, L. 1997. Hamaker constants of inorganic materials, Advances in Colloid and Interface Science, Vol. 70, 125-169.         [ Links ]

[2] Debrincat, D.P., Solnordal, C.B. and van Deventer, J.S.J. 2008. Characterisation of inter-particle forces within agglomerated metallurgical powders, Powder Technology, 182, 388-397.         [ Links ]

[3] Eichenlaub, S., Gelb, A. and Beaudoin, S. 2004. Roughness models for particle adhesion, Journal of Colloid and Interface Science, 280, 289-298.         [ Links ]

[4] Feddema, T., John, Xavier P. and Brown, R. 2001. Micro-assembly planning with van der Waals force, Journal of Micromechatronics, Vol. 1(2), 139-153.         [ Links ]

[5] Fukuda T. & Arai F. 1999. Microrobotics, Handbook of industrial robotics. New York: John Wiley & Sons, Inc., 187-198.         [ Links ]

[6] Komvopoulos, K. 1996. Surface engineering and microtribology for microelectro-mechanical systems, Wear, 200, 305-327.         [ Links ]

[7] Li, Q., Rudolph V. and Peukert, W. 2006. London-Van der Waals adhesiveness of rough particles, Powder Technology, 161, 248-255.         [ Links ]

[8] Matope, S. and van der Merwe, A.F. 2010. Micro-material handling employing Van der Waals forces, Proceedings of the International Conference on Competitive Manufacturing (COMA 10), Stellenbosch University, 3-5 February 2010, 261-267.         [ Links ]

[9] Okazaki, Y., Mishima, N. and Ashida, K. 2004. Microfactory - Concept, history, and developments, Journal of Manufacturing Science and Engineering, Vol. 126, 837-844.         [ Links ]

[10] Parsegian, V.A. 2006. Van der Waals forces: A handbook for biologists, chemists, engineers, and physicists. Cambridge University Press.         [ Links ]

[11] Raatz, A. and Hesselbasch, J. 2007. High-precision and micro assembly, Proceedings of the International Conference on Competitive Manufacturing, COMA'07, Jan-Feb, 321-326.         [ Links ]

[12] Rabinovich, Y.I., Adler, J.J., Ata, A., Singh, R.K. and Moudgil, B.M. 2000. Adhesion between nanoscale rough surfaces II. Measurement and comparison with theory, Journal of Colloid and Interface Science, 232, 17-24.         [ Links ]

[13] Suresh, L., Suresh, Y. and Walz, J.Y. 1997. Direct measurement of the effect of surface roughness on the colloidal forces between a particle and flat plate, Journal of Colloid And Interface Science, 196, 177-190.         [ Links ]

[14] Thoreson, E.J., Martin, J. and Burnham, N.A. 2006. The role of few-asperity contacts in adhesion, Journal of Colloid and Interface Science, 298, 94-101.         [ Links ]

[15] Van der Merwe, A.F. and Matope, S. 2009. The physical design of micro-grippers actuated by Van der Waals forces for use in micro-material handling. Proceedings of the 23rd SAIIE Annual Conference, Roodevallei Country Lodge, Pretoria, 28-30 October 2009, 178-188.         [ Links ]

[16] Zhang, H.W., Wang, J.B., Ye, H.F. and Wang, L. 2007. Parametric variational principle and quadratic programming method for Van der Waals force simulation of parallel and cross nanotubes, International Journal of Solids and Structures, 44, 2783-2801.         [ Links ]



* Corresponding author.
1 The author was enrolled for a PhD (Manufacturing Engineering) degree in the Department of Industrial Engineering, University of Stellenbosch.

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