Research

Myopia or short-sightedness is a global public health problem. In many countries, myopia has reached epidemic levels, imposing a huge economic burden due to the need for purchasing corrective glasses. In recent generations, the prevalence of myopia has increased significantly and this indicates a strong environmental influence on the onset and development of myopia. There is increasing evidence from recent studies, showing a link between the amount of time spent outdoors and the development of myopia. This crucial information suggests that outdoor time is a modifiable risk factor for myopia. The main hypothesis that researchers are investigating is the difference in the nature of light (spectral composition and intensity) between natural and artificial sources. Bright light stimulates increased release of dopamine, a neurotransmitter which is found in the retina. Dopamine is important for retinal signaling and can influence refractive development. In this study, we have developed a novel FitSight wearable tracker device and companion app. The FitSight system was trialled in a small one-week study of 23 children in Singapore (mean ± standard deviation age: 9.2 ± 1.4 years). The tracker was able to record the wear time of the users and also the amount of time the wearer was outdoors. The companion smartphone app incorporated gamification features to encourage the children to achieve a higher amount of outdoor time. This novel FitSight system has the potential to complement outdoor programmes organised through school, community and national initiatives. In a second study, the team evaluated the effect of wearing sunglasses and hats on the effect of light intensity when outdoors. A 3D printed mannequin embedded with light sensors was used to measure the illuminance of white light at various indoor and outdoor locations under a variety of conditions. The main goal of the study is to investigate the effect of sun-protection gear (against harmful UV light) on the potential benefits of outdoor time. The results show that even while wearing sunglasses and a hat, the light intensity outdoors is still considerably higher than in the indoor setting. In summary, children should be encouraged to spend more time outdoors in the day while using sun-protection measures to prevent myopia.

According to the World Health Organisation (WHO), chronic respiratory diseases exert a heavy health burden globally, especially in low- and middle-income countries. For example, chronic obstructive pulmonary disease (COPD) is the cause of 3.23 million deaths in 2019, making COPD the third leading cause of death worldwide.  While respiratory diseases can be detected and monitored by healthcare professionals using gold standard spirometry tests done in clinical settings, some patients lack access to timely medical intervention. There is currently a lack of low-cost technologies for ubiquitous monitoring of lung health. Digital stethoscopes exist, but they can be prohibitively expensive and lack scalability. Therefore, there is an urgent need to develop technologies and strategies that enable or enhance remote assessment of lung health. In this project, low-cost MEMS microphones will be embedded within the chestpiece of 3D printed stethoscopes for digital auscultation of the respiratory system. An observational study will be conducted using the 3D printed digital stethoscopes. Sound signals recorded at selected locations will be processed using machine learning to explore the potential for detecting lung conditions. Through this feasibility study, the goal is to test and validate new technologies and approaches for realising low-cost, ubiquitous sensing for improving respiratory healthcare. This project is well-aligned with Goal 3 of the of the United Nations (UN) Sustainable Development Goals as it aims to make quality respiratory healthcare more accessible to patients in need.

Electroconvulsive therapy (ECT) is widely acknowledged as a highly effective treatment for major depressive disorder, and transcranial brain stimulation techniques in general are of great interest for therapeutic neuromodulation and neurostimulation. It is however difficult to determine the effect of electrical stimulation on the brain due to the complex current pathway between the electrodes, which cannot be readily visualized. Computational models of the human head, combined with a finite element implementation of the Laplace equation, can be used to provide information on the electrical stimulus, such as voltage, current density and electric field distributions, helping to understand the effect of transcranial stimulation on particular brain regions of interest.  The effects of different electrode configurations can be safely simulated and optimized based on patient-specific geometry to obtain the best treatment outcome and minimized associated risks. In addition, impacts of brain structural anomaly on treatment outcome can also be investigated to ensure treatment is beneficial in such cases.

Graphene is known to have high specific surface area and excellent thermal/electrical conductivity, which sees itself in applications such as wearable electronic and energy storage. Recently a graphenic nano-materials called laser-induced graphene (LIG) has been widely investigated due to its easy, cost-effective and scalable synthesis. LIG is produced through a one step laser treatment of commercial polyimide (PI) film substrate under an ambient atmosphere. However, the potential of LIG for use in technological applications is limited by its weak adherence on the PI substrates. In order to realise the full potential of LIG, it is necessary to preserve the LIG flakes’ connectivity and robustness. One way is to infuse it with other materials such as plastic and rubber. In this project we propose to embed LIG in fibre-reinforced composites as smart sensors for health monitoring. The excellent thermal and electrical conductivity of LIG offers an extremely versatile and wide-range sensing platform which can be  exploited to detect various physical quantities in a composite structure such as moisture uptake, strain/stress, damage area, fatigue crack propagation, etc. The scope of the project includes: (1)  optimisation of the sensitivity of LIG’s properties to external environment, (2) integration of LIG in fibre-reinforced composites, and (3) testing and validation of the sensing system at the component level.

Carbon fibres have been commercially reclaimed from high-value composite waste and end-of-life components using pyrolysis. The fibres typically can retain at least 90% of its tensile strength. However recycled fibres are generally discontinuous, fluffy, and entangled. They are commonly reprocessed into randomly orientated non-woven textile fabrics to be used with the liquid compression moulding or sheet moulding compounding to manufacture lower-value non-critical secondary structures. The project aims to reconsider recycled carbon fibres in novel applications to push up its value in the circular economy for economic and environmental benefits. For this purpose, they need to be hybridised with continuous fibre architecture to achieve enhanced mechanical properties and other functionalities. Experimental tests will be designed to develop reliable datasets to understand the capabilities of non-woven recycled fibre fabrics and its properties.

Harvesting energy from ambient sources to power sensors has become a focal area of research. Recent studies indicate that extracting fluid flow energy from Vortex-Induced Vibrations (VIV) is a promising approach for Energy Harvesting Devices (EHDs). In its basic form, a VIV-based EHD consists of a flow past a bluff body, where the resulting vortex shedding is used to vibrate a mechanical oscillator that houses a transducer. Self-sustained flow oscillations emanating from flow over cavity cut-outs have been studied for many decades, primarily focusing on controlling the tones and noise generated by the cavity flow. The current study aims to investigate the potential of cavity flows for energy harvesting and design a cavity flow-based energy harvester. The objectives of the proposed research are to quantify the energy harnessed from cavity flow oscillations using a piezoelectric transducer in different configurations and to establish the effects of Reynolds number, body geometry, piezoelectric material, design configuration and load resistance on the power generated. The approach is both experimental and computational.

Thermal spraying is a technology that enhances or restores the surface of a solid material. The process can be used to apply coatings to a variety of materials and components in order to provide resistance to wear, erosion, cavitation, corrosion, abrasion or heat. It is defined as a group of coating processes in which finely divided metallic or non-metallic materials are deposited in a molten, semi-molten, or solid condition to form a coating. The thermal spray processes can be categorized into three basic groups according to the method of energy generation such as (1) combustion (flame spray, HVOF) and (2) plasma spraying (wire-arc spraying), and (3) compressed gas expansion (cold spray). There are several challenges to obtain high-quality functional deposits because (1) every material combination (coating and substrate) is unique based on its intended applications, (2) dependent on selection of complex process parameters, and (3) requires an in-depth understanding of their microstructure and mechanical properties. These investigations need to be systemically carried out to ensure the deposited coating can be useful for the automotive and aerospace industries.

Metallic structures are widely used in Malaysia's manufacturing sector, accounting for RM 95 billion of the industry. However, metal such as steel is prone to corrosion and manufacturing defects, resulting in catastrophic failures. A solution to these issues is a metallic-based composite reinforced with different metallic alloys which are known for improved strength and toughness. We will attempt to create, explore, and fundamentally study a metal-based composite reinforced with selected alloys that will be fabricated using hybrid arc welding (HAW) process which is a combination of Gas Metal Arc Welding (GMAW), Gas Tungsten Arc Welding (GTAW), and Shielded Metal Arc Welding (SMAW). This fabrication method is cost-effective, portable, easily adaptable by workers and can be deployed on-site to produce high-performance metal-based composite. Preliminary results showed that the steel-based composite by HAW process has a 20% and 35% higher tensile strength and strain, respectively as compared to the single GMAW process. The research objectives would include 1) to develop and optimise process parameters for the HAW process, 2) to identify and study the microstructure of HAW metal-based composite that contributes to strength and toughness and 3) to evaluate the mechanical properties of HAW metallic-based composite in terms of strength and toughness. The output of this research will enable to use of metal-based composite for building construction, airframe structures, automotive chassis and wind turbine components.