We derive the thin film approximation including roughness-induced correctors. This corresponds to the description of a confined Stokes flow whose thickness is of order ε (designed to be small) ; but we also take into account the roughness patterns of the boundary that are described at order ε, leading to a perturbation of the classical Reynolds approximation. The asymptotic expansion leading to...

Mussel-inspired polydopamine (PDA) chemistry and electroless deposition approaches were used to prepare stable superhydrophobic coatings on wood surfaces. The as-formed PDA coating on a wood surface exhibited a hierarchical micro/nano roughness structure, and functioned as an “adhesive layer” between the substrate and a metallic film by the metal chelating ability of the catechol moieties on PD...

The structural organization of four microbial communities was analysed by a novel computer program, COMSTAT, which comprises ten features for quantifying three-dimensional biofilm image stacks. Monospecies biofilms of each of the four bacteria, Pseudomonas: putida, P. aureofaciens, P. fluorescens and P. aeruginosa, tagged with the green fluorescent protein (GFP) were grown in flow chambers with...

In this work, the adhesion of biomimetic polydimethylsiloxane (PDMS) pillar arrays with mushroom-shaped tips was studied on nano- and micro-rough surfaces and compared to unpatterned controls. The adhesion strength on nano-rough surfaces invariably decreased with increasing roughness, but pillar arrays retained higher adhesion strengths than unpatterned controls in all cases. The results were a...

In this study, microelectro-discharge (micro-ED) milling of nonconductive ZrO2ceramicsis investigated using a Cu tool electrode in kerosene dielectric. An adhesive Cu foil is firmly attached on the workpiece to initiate the sparks. After the machining of Cu foil, an electrically conductive carbonic layer is formed on the ceramic workpiece disassociating the kerosene dielectric, which allows mic...

The capability of evaluating and managing rockfall related risks is largely based on numerical modelling. Nevertheless, the reliability and accuracy of rockfall models is greatly affected by the strong uncertainty and spatial variability which characterise all the relevant parameters. In particular, 3D effects related to the variability of slope geometry and micro-topography play a major role i...

The controlled removal of material conducted with the tip of an atomic force microscope (AFM) probe is a technique that has started gaining increased attention in recent years within the micro and nano manufacturing research community. The attractive characteristics of this process are that it is relatively simple to implement and low-cost compared with vacuum-based lithography techniques for m...

In many investigations, large number of process, or design parameters that are initially thought to affect the outcomes or outputs may not really have statistical significant influence on them. Screening experiments are used to identify the key parameters (factors) that significantly affect these outcomes. In this investigation, Plackett-Burman screening design was used to identify the factors ...

Superhydrophobic surfaces exhibit extreme water-repellent properties. These surfaces with high contact angle and low contact angle hysteresis also exhibit a self-cleaning effect and low drag for fluid flow. Certain plant leaves, such as lotus leaves, are known to be superhydrophobic and self-cleaning due to the hierarchical roughness of their leaf surfaces. The self-cleaning phenomenon is widel...

The aim of the present study was to examine bone response to micro-rough titanium implants. Forty coin-shaped implants were divided into eight groups according to their surface roughness. The first group had electropolished surfaces. The surfaces of implant groups 2-8 were blasted with TiO2 particles with incremental grain sizes ranging from 7.5-12.5 to 270-330 microns. Five implants from each ...