Surface-force-induced deformations of monodisperse polystyrene spheres on planar silicon substrates

Abstract

The time dependence of the surfaceforceinduced contact radius between glass particles and polyurethane substrates: Effects of substrate viscoelasticity on particle adhesion Conduction of heat from a planar wall with uniform surface temperature to a monodispersed suspension of spheresThe contact radii between polystyrene spheres, having diameters between approximately 1.5 and 12 pm. and polished silicon wafers, arising from adhesion forces, were determined using scanning electron microscopy. It was found that the contact radius varied approximately as the square root of the particle radius. This dependence is consistent with nonelastic response models of adhesion, such as those proposed by Krupp [H. Krupp, Adv. Colloid Interface Sci. 1. III (1967) J and by H. M. Pollock, Acta Metal!. 32, 1323 ( 1984) J. but is inconsistent with various elastic response models which assume Hertzian deformations. The experimentally determined contact radii are also compared to those obtained for polystyrene spheres on a polyurethane substrate [D. S. Rimai, L. P. DeMejo, and R. C. Bowen, J. App!. Phys. 66, 3574 (1989)].

Cleaning of Dust between Interactive Contact Surfaces by Application of Normal Loads of Artificial Stainless-Cantilever in AFM

“…D. M. Schaefer et al (8) determined that the non-linear relations between pull-off force and applied load are dependent on contaminants present and the humidity of the surface by using the micro spheres the polystyrene (PS) and polyethylene (PE) against the silicon wafer surface utilizing a commercial silicon cantilever. Additionally, in concurrence with D. S. Rimai et al (9) , they mentioned that changes in the contact areas between the substrate and sphere are non-linear but they did not clearly mention the reasons behind this. R. D. Boyd et al (10) recognized that the roughness and surface shape of the substrate influenced the attachment and resistance against bacteria over substrate, and requested the force, which is needed for the removal of the bacteria cell, by decreasing abrading using a commercial cantilever against the bacteria cell over a stainless substrate.…”

“…Much research has been done in conjunction with cantilevers in order to understand the phenomena which occur on the interactive contact surfaces. (4)- (9) . In order to measure the surface force between the colloid sphere and the flat surface in the solution condition W. A. Ducker et al (4) (5) used a cantilever attached to micro spheres 1µm and 50µm in size.…”

Analysis of Contact Interactions between a Rough Deformable Colloid and a Smooth Substrate

“…Several experimental techniques exist to investigate the contact area between colloids and surfaces. These include the surface force apparatus (38), the nanoindentors (39), and the scanning electron microscope (20). To evaluate a contact area model of the form described in Eq.…”

“…Rimai et al have extensively studied the deformation of PSL spheres in contact with silicon and polyurethane substrates with a scanning electron microscope (SEM) (20)(21)(22)(23)(24)(25). They have experimentally determined the contact radius as a function of colloid radius, enabling the determination of the appropriate adhesion-induced deformation model.…”

Surface Forces related to the Accumulation and Dispersion of Dust due to the Locomotion of a Cantilever

“…To understand phenomena on the interactive contact surfaces, many studies related to the cantilever have been conducted (5)- (10) . Since certain contact surface conditions can prevent a micro-robot from moving, we should consider the accumulation and dispersion of dust between micro/nano-interactive contact surfaces and their relation to the locomotion of micro-robots and micro-devices.…”