Far infrared (FIR) detectors can easily detect items with a temperature ranging from 0 to 150 °C. They are the key components for the next-generation smart city and smart life, and indispensable to smart automobiles, night visions, smart home appliances and health monitors. The current commercial FIR detectors usually adopt a vacuum cavity structure for good performance. However, this complex structure requires multiple fabrication steps and can be easily broken during the fabrication, the sealing and the application, which leads to low yield and increases the cost.
To increase the yield and reliability and decrease the cost of FIR detectors, working together with Excelitas Technology, a global leader of infrared (IR) detectors and Associate Professor Lance Li from KAUST, Saudi Arabia, Professor Tay Beng Kang’s group from School of Electrical and Electronic Engineering is working on the design and fabrication of novel far infrared (FIR) detectors based on two dimensional materials. A novel planar structure without vacuum cavity has been designed by this team, which is much more robust and requires only half of the fabrication processes of the current vacuum cavity structure, increasing the yield and slashing the cost. Also, although the two dimensional materials, such as graphene and transition metal dichalcogenides, are as thin as 1/100,000 of a hair, their application in this novel planar FIR detectors will further improve the performance of the detectors.
Figure: FIR Applications and detectors
The phenomenon of urban heat island (UHI) effect can be found in many cities around the world, especially in built-up dense cities. Large amount of heat due to solar irradiation is absorbed by urban fabric materials e.g. buildings, pavements and other impervious surfaces which in turn heat up the surrounding air, causing urban ambient temperature to rise. This heating effect is further exacerbated by insufficient natural cooling mechanisms (e.g., wind ventilation, vegetation, water bodies, etc.) due to the dense urban developments. UHI effect is found to adversely affect the comfort and well-being of people. Finding an effective solution to UHI effect will be impactful to environmental quality and liveability especially for tropical metropolis with year-round hot and humid climate, including Singapore.
In this project led by Assistant Professor Wan Mun Pun from the School of Mechanical & Aerospace Engineering in partnership with Institute of Chemical & Engineering Sciences (ICES), A*STAR, NIPSEA Technologies (Nippon Paint) and government agencies including Housing & Development Board (HDB) and Building & Construction Authority (BCA), the team aims to develop a mitigation solution for UHI effect based on the Cool Surface technology.
Cool Surfaces are materials having high albedo that reduce the solar radiation absorption when applied on urban surfaces, thereby reducing urban ambient temperature. A comprehensive modelling and field measurement study will be conducted to provide the foundation for formulating strategy for Cool Surface deployment in Singapore. A suite of high-performance Cool Surface materials featuring high solar reflectance, high durability and self-cleaning properties will also be developed for deployment on different urban surfaces. Real-world performances of the new Cool Surface materials will be examined through field test beddings.
Figure 1: Cool surfaces reduce solar radiation absorption by urban impervious surfaces
Automatic Robot System for Indoor High Rise Spray Painting
Funded under the NRF Test-bedding and Demonstration of Innovative Research Initiative, Professor Chen I-Ming from the School of Mechanical & Aerospace Engineering and team in partnership with JTC Corporation and AiTech R&D aims to develop a mobile robot system that is equipped with a novel long reach mechanism for automatic high ceiling and wall painting applications.
The mobile robot and the reaching manipulator can be configured to cope with painting tasks at different heights and the configuration can be done in either automatic or semi-automatic manner. The indoor spray-painting robot will be able to scan the working environment, construct a 3D model of the actual environment, plan and navigate in the environment for the painting task autonomously. The robot will be test-bedded in a suitable construction site at the end of the project. Eventually the robot shall be used a tool to help the contractor to deliver high ceiling and wall painting jobs.
In the gas industry, it is essential to monitor the change of wall thickness of the pipeline, in order to estimate the corrosion rates of the pipe networks for cost effective operation, and be able to send advanced warning signal for possible gas leakage. Conventional thickness evaluation process requires manually scanning of probes over the whole structure, which is especially tedious and challenging for remote locations. There is therefore strong motivation to develop an advanced monitoring system which can be permanently installed in critical locations in the pipeline network, and continuously monitor the wall thickness change of pipelines around these areas.
In this proposed work led by Asst Prof David Fan of the School Mechanical & Aerospace Engineering in collaboration with members from Lloyd's Register Global Technology Centre and Sembcorp, ultrasonic guided wave technology will be explored in conjunction with tomography principles to establish a condition monitoring system for critical areas in the pipe particularly susceptible to corrosion/erosion. The project aims to integrate physics and modelling techniques with the development of the advanced electronics. Compared to other non-destructive examination techniques, the system is able to send early warning signal immediately when thickness of a region is below a threshold; accurately measure the corrosion rate; and save huge cost of setting up measurement in difficult-to-access regions.
Thickness mapping on pipelines using ultrasonic guided wave tomography technique
Smart Cargo Handling Equipment and Battery Management System for Port Sustainable Energy Management
As a world class hub port, Singapore is expected to demonstrate its capability in sustainability. Therefore, there is a strong demand for developing a new and effective solution to achieve green port operations and enhance the productivity/growth simultaneously. The major aim of the project led by Assistant Professor Lam Siu Lee Jasmine from the School of Civil and Environmental Engineering and team in collaboration with members from the PSA Corporation is to design and develop a full featured and generic battery management system (BMS) for cargo handling equipment. This generic BMS is able to perform predictive health monitoring and management of installed energy storage system which is independent of energy storage suppliers.
The concept of this project is based on the state-of-the-art supercapacitor technologies which will allow a 24/7 fully electric solution. The final prototype that is envisioned will be able to outperform the existing competing technologies in terms of functionalities. The new concepts and methods used in the project will drive future research and be widely applicable in various seaport terminals in Singapore and beyond. The research and the knowledge created will contribute to maintain Singapore’s competitive advantage as a hub port and profile as a maritime knowledge hub.
Advanced Cool Coating Integrated with Phase Change Material for Buildings in Tropical Singapore
In this project, Assistant Professor Yang En-Hua of School of Civil and Environmental Engineering collaborates with Assistant Professor Yang Jinglei of NTU school of Mechanical and Aerospace Engineering and researcher at Nipsea Technologies Pte Ltd to develop new building façade coating integrated with phase change material (PCM). The coating consists of a high solar reflective top coat to reject solar radiation heat and a PCM modified skim coat to prevent conductive heat penetration through building envelope as shown in Figure 1.
The research team investigates and maximises the efficacy of PCM in tropical climate. New synthesis routes are developed to encapsulate PCM with inorganic shell to enhance the thermal response of PCM capsules. The PCM capsules are integrated into skim coat to create a new coating formula. Numerical tool for cool coating system performance simulation and evaluation are also developed. It is expected that the research outcomes will greatly reduce cooling load demand for buildings in tropical Singapore.
Figure 1: Cool Façade Coating integrated with Phase Change Material
Preparation of n- and p-type Bi2Te3-based Materials with Enhanced Thermoelectric Performance by Melt-spinning and Spark Plasma Sintering
Energy conversion and storage technologies are becoming increasingly important as more emphasis is given to renewable energy sources. It is known that of all the primary energy we harness and use, only 30% is translated into useful work. A staggering 70% is wasted as dissipated heat during energy conversion, transportation and storage. This huge loss is itself a source of recyclable energy. If the waste heat leakage can be minimised by having the heat harnessed, stored and reused, the additional available energy can be huge. Thermoelectric (TE) devices, which can directly convert heat into electricity or vice versa, could play an important role in the energy market. TE devices can be potentially used as power generators, heat pumps, coolers and thermal sensors, which make them a unique energy harvesting and heat management system. In recent years, interest has increased regarding new applications of power generation through thermoelectric harvesting with applications such as waste heat recovery systems in vehicles, wireless sensor network and consumer applications. The main objective of this project led by Assoc Prof Hng Huey Hoon from the School of Materials Science and Engineering with LG Innotek is to achieve better performing TE materials to increase the efficiency of TE devices, and hence broaden the applications of TE devices.
WiFi is widely used in portable electronics, such as wireless router, mobile, laptop, and tablet PC etc. However, the speed of WiFi is too slow due to its narrow bandwidth and low spectrum efficiency. If the number of WiFi clients increase, the total data rate will drop dramatically since a significant part of time is waste during the competition of each client’s transmission requirement. This sounds counter-intuitive, but it is the consequence of the out-of-date WiFi standard developed from last century.
A new WiFi standard, 802.11ax, was proposed to solve the problems of conventional WiFi. It can greatly improve the speed of WiFi to 10 Gbps, compared with the latest 1.7 Gbps 802.11ac and conventional 54 Mbps 802.11g. Moreover, the new standard is also suitable for outdoor applications and crowded environment such a stadium, transport station, etc.
Recently, an NTU team proposed a world’s first RFIC to implement the new WiFi standard 802.11ax. The team members include 12 members from NTU led by Dr Yi Xiang and Associate Professor Boon Chirn Chye from the School of Electrical and Electronic Engineering, as well as 7 members from Huawei represented by Hu Gengen. The operation frequency of the proposed RFIC is from 5.17 to 5.835 GHz. Three 160 MHz carriers can be aggregated intra-band and inter-band to increase the available bandwidth, so the total bandwidth can be as large as 480 MHz. To avoid the cross-talk, the parallel direct-conversion and double-conversion architecture is proposed. The cascaded PLL structure provides multiple low phase noise LOs. Implemented in GlobalFoundries 65nm LP CMOS technology, this chip occupies 3mm by 2.5mm size. So far two invention disclosures have been generated.
Towards Green Data Centres as an Interruptible Load for Grid Stabilisation in Singapore
In this project, Prof Wen Yonggang of the School of Computer Science and Engineering and team collaborated with Toshiba Asia Pacific Pte Ltd, SP Powergrid Ltd, MIT and University of Southern California to develop solutions to enable data centre to serve as a novel “interruptible” load (i.e. power load that can be scaled down temporally) to stabilise Singapore’s power grid as it integrates more distributed generation and renewables (e.g., PV).
Called Embedded Software as Sensors (ESaS), software hooks are embedded into a range of datacentre subsystems, from chip to system to application level, to monitor ICT activities and power usage in a fine-grained, real-time manner.
The data collected from these virtual sensors are then analysed to construct energy consumption models, which in turn are used to develop optimal algorithms for energy-aware operation of computing, power distribution and cooling systems in the datacentre.
The holistic monitoring and optimisation framework reduces the overall power consumption of a data center, and enables time-shifting of workloads in the data center in response to power fluctuations arising from the integration of distributed generation (DG) and renewable sources to Singapore’s power grid.
As one data center is equivalent to around 10,000 households in electricity demand, by commanding a few data centres to shift their work load temporally instead of coordinating millions of households for demand shaping, this helps to alleviate further stress on the fragile power grid.
This research will have huge impact on the energy management in Singapore, for which solar energy would contribute more than 10% of the total electricity demand. The ESaS framework spearheads in advanced power analytics, facilitating to establish Singapore as a technology leader in datacentre research globally.
Figure 1. Green Data Centre as an “interruptible” load forgrid stabilisation in Singapore: concept diagram.
Figure 2. Application consolidation for energy reduction.
Figure 3. Modular Data Centre Testbed: a) data center testbed; b) host isle; c) cold isle.
Research Cement Flow
Demand for cement has seen dramatic growth as Singapore ramps up its construction activities over the past years. However, one main problem encountered in the transportation of cement lies in its tendency to “choke” regularly during its passage through pneumatic pipes and air-slide conveyors.
Solving these choking instances typically meant stopping the conveyors and finding the choking location and clearing the cement build-up manually, hardly the most efficient or time-saving method.
In a research collaboration agreement between NTU, Maritime and Port Authority of Singapore (MPA) and Jurong Port (JP) under the MPA-JP Green Port and Productivity Solutions R&D Programme, Assistant Professor Daniel New and team will utilise the latest laser-diagnostic measurement tools to probe the flow conditions under which cement choking instances will occur and the flow mechanisms that trigger and encourage these choking instances. This will be done through the novel deployment of a unique two-phase particle-image velocimetry system that will measure both the flow fields of the air and cement particles simultaneously.
Insights from the research will then be harnessed to come up with potential solutions jointly with Jurong Port (JP) to clear future cement choking instances more efficiently and in less time. For a more realistic study, actual air-slide conveyor and pneumatic pipe flow conditions at JP’s facilities will also be scaled down accordingly to simulate more closely the physical working conditions. Other than resolving cement choking instances, this investigation may also shed light on the flow behaviour of other important particulate or granular flows such as flour or sugar during their transportations as well.