Roseleena Jaafar

Hybrid-Actuated Finger Prosthesis with Tactile Sensing

Finger prostheses are devices developed to emulate the functionality of natural human fingers. On top of their aesthetic appearance in terms of shape, size and colour, such biomimetic devices require a high level of dexterity. They must be capable of gripping an object, and even manipulating it in the hand. This paper presents a biomimetic robotic finger actuated by a hybrid mechanism and integrated with a tactile sensor. The hybrid actuation mechanism comprises a DC micromotor and a Shape Memory Alloy (SMA) wire. A customized test rig has been developed to measure the force and stroke produced by the SMA wire. In parallel with the actuator development, experimental investigations have been conducted on Quantum Tunnelling Composite (QTC) and Pressure Conductive Rubber (PCR) towards the development of a tactile sensor for the finger. The viability of using these materials for tactile sensing has been determined. Such a hybrid actuation approach aided with tactile sensing capability enables a finger design as an integral part of a prosthetic hand for applications up to the transradial amputation level.

Modeling and Multi-Response Optimization on WEDM Ti6Al4V

Wire electrical discharge machining (WEDM) is a material removal process of electrically conductive materials by the thermo-electric source of energy which is extensively used in machining of materials for a highly precision productivity. This work presents the machining of titanium alloy (TI-6AL-4V) using WEDM with a brass wire diameter of 0.25mm.The objective of this work is to study the influence of three machining parameters, namely peak current (IP), feed rate (FC) and wire tension (WT) to cutting speed and surface roughness. Response Surface Methodology was used to develop second order model in order to predict cutting rate and surface roughness responses. The results showed that the average percentage error between the predicted and experimental value for both models was less than 2%.Furthermore, the developed models were used for multiple-response optimization by desirability function approach to determine the optimum machining parameters. These optimized machining parameters are validated experimentally, and it is observed that the response values are in good agreement with the predicted values.

The experience of the Faculty of Mechanical Engineering, Universiti Teknologi MARA, Malaysia, with accreditation by the UK Institution of Mechanical Engineers

The Faculty of Mechanical Engineering Universiti Teknologi MARA, Malaysia, has sought accreditation from the UK Institution of Mechanical Engineers (IMechE) for its Bachelor of Engineering (Honours) Mechanical programme. To be accredited, the programme must satisfactorily incorporate the UK-SPEC general learning outcomes, which have to be mapped to the Facultys programme educational objectives and programme outcomes. The contents of the various courses comprising the programme have to be integrated to bring all the learning outcomes together and taught in a systematic approach to become a total system. In the project design, issues such as sustainable development, risk, health and safety, and professional ethics are areas of concern. This paper describes how IMechEs UK regulations and requirements are being met, and relates the Facultys experience with the accreditation process.

Modeling and Influence of Machining Parameters on Titanium Aloy

Wire electrical discharge machining (WEDM) is a material removal process of electrically conductive materials by the thermo-electric source of energy which is extensively used in machining of materials for a highly precision productivity. This work presents the machining of titanium alloy (TI-6AL-4V) using WEDM with a brass wire diameter of 0.25mm.The objective of this work is to study the influence of three machining parameters, namely peak current (IP), feed rate (FC) and wire tension (WT) to cutting speed and surface roughness as a responses. Response Surface Methodology was used to develop second order model in order to predict cutting speed and surface roughness responses. The results showed that the average percentage error between the predicted and experimental value for both models was less than 2%. Effects of each parameter and their interaction with percentage contribution ratios (PCR) are included for each response.

Evaluation of nugget formation in resistance spot welding of dissimilar materials

The scope of this research work focuses on resistance spot welding (RSW) for different material combination where the nugget formation process and microstructure were investigated using both finite element method (FEM) and experimental measurement. The finite element code SYSWELD was utilized for the simulation of a two dimensional axis-symmetric finite element model using customized electrode meshing inorder to develop a thermal-mechanical-electrical characteristic of the spot welds. The model was developed for welding dissimilar metals 1.2 mm low carbon steel and 1.0 mm DP600. The RSW simulation parameters such as welding current, electrode force, welding time and the temperature distribution of the welded sheets and electrodes were considered throughout the study. For the experimental process, similar welding parameters as used in the simulation were applied to the RSW machine. It was found that the weld nugget and HAZ size from numerical simulations were in good agreement with experimental results. Whereas for the microstructure, reasonable results were achieved between the predicted results and experimental observation.

Towards an Entrepreneurial Model of University: Issues and Challenges in Managing Intellectual Property (IP) and Its Commercialization (C)

There are a number of procedures required by researchers to undergo before the outcome of their research products known as intellectual properties (IP) can get to the market for economic values. In this volume, researchers examine the interrelationships among these procedures, policy issues and communication flow with commercialization experienced by researchers in selected Malaysian higher institutions of learning that engaged in IP and commercialization. Methodologically, the study has been approached from quantitative perspective using questionnaire. The results from the study have shown that a positive significant relationship exists between the IP-Commercialization procedures and internal critical success factors (CSFI) towards successful commercialization of the IP products at the centres with beta values of 0.564, p<0.001. A similar significant positive relationship exists between the causal link of IP and commercialization procedures and external critical success factors (CSFE) with beta coefficient values of 0.429, p<0.001. In addition, both CSFI and CSFE have significant impact on communication flow related to IP and commercialization of research products with a beta value of 0.264 and 0.317, p<0.001 respectively. Furthermore, the path coefficients between policy issues in IP and commercialization of products has shown a significant impact on communication flow and actual commercialization of the intellectual products experienced by respondents with high beta value of 0.256 and 0.343, p<0.001 respectively. The same similar positive causal link can be inferred between communication flow and the commercialization of the intellectual products experienced by respondents with a beta value of 0.229, p<0.001. In addition, hypotheses H1, H2, H3, H4, H5, H6 and H7 in the study are supported with an alpha-value less than 0.001 respectively. It is hoped that due attention would be paid to all the recommendation put forward in this study for better enhancement of IP and commercialization of research products at universities.

Towards Biomimetic Actuation in Prostheses Using Shape Memory Alloy

Shape Memory Alloy (SMA) has been identified as an ideal candidate to actuate the finger joints of hand prosthesis due to its silent operation, small size, high force to weight ratio and operational similarity with human muscles. When current is applied to a SMA wire, the material is heated up. A phase transformation from Martensite to Austenite takes place and the wire contracts. This work evaluates the displacement and force produced from the contraction of a type of SMA wire, i.e. Nitinol (Ni-Ti). The displacement is determined by a linear potentiometer while the force is determined by a load cell. Furthermore the impacts of varying the bias force exerted on the SMA wire and the input current passed through the wire are investigated. Such insight into the characteristics of SMA can be used to realize biomimetic actuation in order to improve the dexterity of hand prosthesis.

Ergonomics evaluation of training activities postures in engineering workshop at Vocational Training Centre

This paper presents a detailed study to evaluate awkward postures of trainees when conducting practical training activities in engineering workshops at Vocational Training Centre (VTC). The awkward postures contribute to uncomfortable conditions and may cause musculoskeletal injuries. Subjects of the study are vocational training (VT) trainees selected from various engineering workshops to identify their posture conditions during their practical training sessions. These selected trainees are males and the average age is 19 years old. Physical observation using digital camera was used to identify the awkward postures during these activities and Rapid Entire Body Assessment (REBA) technique was used to determine the level of ergonomic risk due to these awkward postures. Based on the observation and assessment, evidences showed that the trainees are exposed to ergonomic risks with 40% and 60% of the activities at high and medium level respectively. There is a high probability of causing musculoskeletal problems and relevant solutions can be introduced to reduce ergonomics hazard for practical training activities.

Optimizing Robotic Welding Parameter of Single Passed Butt Joint under Simultaneous Consideration of Multiple Response Using Multi Objective Taguchi Method

This paper presents an alternative method to optimize parameters on single V butt welding. The effect of single-passed welding parameters such as current, voltage, welding speed and width of weaving movement on major welding defects by using a one-sided clamping method was investigated. The optimum parameter values were analyzed using Multi Objective Taguchi Methods (MTM) which started with the application of the common Taguchi methods (L8) Orthogonal Array (OA) and Total Normalized Quality Loss (TNQL) followed by ANOVA under simultaneous consideration of response weighting factors. Further, the value was analyzed by employing Multi Signal to Noise Ratio (MSNR). For the experimental study, a robotic welding system ABB IRB 2400/16 with digital welding power source KEMPPI Pro Evolution ProMIG 540 MXE with shielding gas Argon 80% and Carbon Dioxide 20% were applied. The material used is low carbon steel with 4 mm plate thickness. Based on the verification test result, it is found out that MTM can be used as an alternative method to investigate the optimum value of single passed welding parameter with multiple quality features.

Reducing Non-Value Added Process for an Automotive Component Using Finite Element Modeling

The research work focuses on sheet metal stamping process simulation of an automotive component known as bracket assembly upper spring made from low carbon steel and has axis-symmetrical cup shape that employs four multi-stage drawing processes. Non-value added drawing stages (optimization process) reduced and portrayed from the formability simulation result using finite element modeling (FEM) method. The modified design, with reduction of one draw stage, showed that the risk of the component to form cracks is lesser, the material elements are further away from the failure zone of the forming limit diagram (FLD) and it meets the requirement for minimum thickness. The FEM simulation was able to predict the formability and optimize the design of a sheet metal forming process that lowered the product cost and improve cycle time.