Stephen Matope

MICRO-MATERIAL HANDLING EMPLOYING E-BEAM GENERATED TOPOGRAPHIES OF COPPER AND ALUMINIUM

CITATION: Matope, S., Van der Merwe, A. F., Nemutudi, R., Nkosi, M. & Maaza, M. 2011. Micro-material handling employing e-beam generated topographies of copper and aluminium. South African Journal of Industrial Engineering, 22(2):175-188, doi:10.7166/22-2-24.

System dynamics of renewable energy technology adoption

The adoption of renewable energy technologies (RET) has been facing a number of barriers and constraints due to dynamic interaction of adoption related factors. This paper simulates from a systems dynamics point of view the dynamic behavior of the RET adoption process. Complex dynamic interactions between technology adopters, policy makers and policies are captured based on systems thinking. Based on a set of input policy parameters and variables, the behavior of RET adoption is investigated. Sensitivity experiments and further “what-if” experiments are conducted in this study. Useful managerial insights are drawn from the simulation results, relevant for policy makers concerned with renewable energy technologies.

MICRO-MATERIAL HANDLING, EMPLOYING E-BEAM COATINGS OF COPPER AND SILVER

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. OPSOMMING Van der Waalskragte en ander bindingskragte hou steeds groot uitdagings in vir mikromateriaalhantering. As gevolg van hierdie bindingskragte stel meganiese gryptoerusting nie die mikro-partikels vry nie. Hierdie artikel ondersoek hoe die Van der Waalskragte gebruik kan word vir die mikro-materiaalhanteringsproses deur die gebruik van oppervlakgrofheid gegenereer deur ’n e-straal-laagbedekking van koper en silwer op silikon. ’n Atoomkrag mikroskoop, model Asylum MFP 3 D-Bio met weergawe 6.22A programmatuur, is gebruik om die kragte deur die oppervlakke uitgeoefen te meet. Daar is gevind dat ’n silwer laagbedekking met ’n oppervlakgrofheid van 1.41nm wortel-gemiddelde-kwadraat (wgk) die hoogste Van der Waalskrag uitoefen, gevolg deur ’n koper laagbedekking met ’n oppervlakgrofheid van 2.72nm wgk; ’n koper laagbedekking met ’n grofheid van 217nm wgk het die kleinste krag uitgeoefen. Dit impliseer dat, vir ’n betroubare mikro-materiaalhanteringsisteem, hierdie laagbedekkings geskik is vir die interaktiewe oppervlakke van die plasingsposisie, die mikro-gryper en die optelposisie. a a a a a a a a a a

Robotic prosthetic challenges for clinical applications

This paper presents the challenges currently being encountered for the accelerated application of robotic prosthetics in clinical applications. The main goal is to evaluate technological challenges and methods that have been utilized to foster development of the intelligent artificial robotic prosthetics. Success that have been achieved during in vitro researches were evaluated based on clinical application and ultimately commercialization of the designs. Emphasis is on cost of researches, designs, commercialization and accessibility to the general populace. Although the use of robotic prosthetic limbs has been largely accepted by the scientific world, the amputees have been encountering several disadvantages such as weight increase, intricate and frequent maintenance and noisy actuation coupled with unreliable control system as a result of poor signal acquisition and processing. Novel techniques proposed such as pattern recognition for feature extraction and machine learning for robustness, adaptability and stability were either based on simulations in softwares such as Autodesk, OpenSim or Matlab resulting in limited prototypes and hardware developments thereby reducing the clinical applicability of the technologies. Even up to this period of time permanent assistive devices are viewed by the physically challenged as separate, lifeless mechanisms and not intimate extension of the human body structurally, neurologically and dynamically.

Dynamics of information technology adoption in a complex environment

In the real world, the adoption of information technology (IT) innovations is a complex process involving three main entities: (i) promoters, who facilitate the adoption process, (ii) inhibitors, who oppose the adoption of technology, and (iii) imitators who are influenced by both promoters and inhibitors. In the presence of promoters and inhibitors, managing technology innovation and adoption is a complex task. Since most of the IT innovations are characterized by these actors, understanding the dynamics of their diffusion and adoption is imperative. This research seeks to develop a system dynamics model to capture the interactive dynamics of IT adoption in a complex environment involving promoters, inhibitors, and imitators. Based on a set of experiments, we investigate via simulation, the behavior of a typical diffusion and adoption process, drawing useful managerial implications for technology policy makers. What-if analyses experiments are carried out in order to obtain further insights into policy design and evaluation for effective technology management.

DIGITALISATION OF SHOP-FLOOR OPERATIONS IN THE SOUTH AFRICAN TOOL, DIE, AND MOULD-MAKING INDUSTRY

Digitalisation has been advocated as a possible strategy to improve the competitiveness of tool, die, and mould-making (TDM) companies in the 21st century. The recent rise of digital technologies, such as Internet of Things devices, now makes digitalisation an achievable reality. This paper focuses on the digitalisation of shop-floor operations in the South African TDM industry through the development of a novel mobile data collection (MDC) tool known as a shop-floor management system (SMS). The developed SMS was deployed to, and validated in, a selected tooling company for various products. The developed system improved the shop-floor’s real-time data collection.

South African iron and steel industrial evolution : an industrial engineering perspective

The paper focuses on the evolution of the South African iron and steel industry from the industrial engineering perspective. The earliest ironmaking in South Africa dates to the fifth century CE; but the major evolution of the industry began in 1882 and, by the year 1934, steel production from native ore was in full swing. The study highlights the major developments in South Africa’s iron and steel industry, and ends by exploring the extent of the application of industrial engineering techniques to published research into the steel industry.

Lean applications : a survey of publications with respect to South African industry

CITATION: Dondofema, R. A., Matope, S. & Akdogan, G. 2017. Lean applications : a survey of publications with respect to South African industry. South African Journal of Industrial Engineering, 28(1):103-113, doi:10.7166/28-1-1660.

INVESTIGATING THE EFFECTS OF PASSIVE MECHANICAL ANKLE ON UNILATERAL OSTEOMYOPLASTIC TRANSTIBIAL AMPUTEES

Purpose The study presents an investigation of the asymmetries in normal gait associated with the use of prosthetic mechanical passive ankle devices when performing ambulatory-related activities fo...

An intuitive teachable micro material handling robot with Van der Waals gripper design and development

There is an increasing need for micro material handling systems that are not only accurate but also intuitive. This is pertinent when considered in light of a micro piezoceramic pick and place case study. The case study forms part of a collaboration with the Chemnitz University of Technology. Conventional robot-teach methods require careful and time consuming incremental movements when picking and placing micro components. This is due to the fact that a very specific contact force needs to be established. If this specific force is exceeded, damage will result. This is especially relevant in light of the use of a Van der Waals gripper for piezo-ceramic micro part positioning. A system has thus been developed that incorporates a force teach technique in a coarse to fine micro material handling system. A number of issues arise in the interaction between the coarse positioning system and the fine positioning. These are addressed by the design of the calibration system. A series of actions learned by the system can be applied over a coarse 500 mm range with a fine 3 μm repeatability. The systems ability to implement scalable, responsive, and intuitive control is paramount to its applicability to the considered case study.