The general idea behind Smart City goes beyond the use of information and communication technology to minimise the demand for resources and to reduce emissions. It also means enhancing city efficiency, promoting business productivity, improving the quality of life and enhancing climate resilience.
With Smart City as one of CityU’s five overarching themes, researchers from various disciplines are working on innovative solutions that address regional and global concerns and challenges such as sustainable energy, climate change, environmental degradation, urban planning, government regulation and the law.
More stable and environmentally friendly solar cells
Pioneering research led by Professor Alex Jen Kwan-yue, Lee Shau Kee Chair Professor of Materials Science, has revealed an exciting new way to harness solar power more effectively and in a more environmentally friendly way.
Professor Jen is developing more stable and environmentally friendly perovskite and organic solar cells that are believed to offer more diverse applications for replacing silicon as the future of photovoltaic technology. One of the main concerns has been potential contamination from the lead containing component in perovskites. “As solar cells age, the lead component can potentially leak and leach into the soil through rainwater, for example,” Professor Jen explained.
But Professor Jen’s use of a groundbreaking 2D conjugated metal-organic framework not only improves operational stability but also prevents lead from leaking, making way for the commercially viable, large-scale deployment of the technology. The research outcomes indicate an improved sustainability, good operational stability and enhanced power conversion efficiency.
Building a compact system for terahertz technology and 6G communications
CityU researchers are advancing the development of terahertz (THz) technology for 6G communications, imaging and spectroscopy. The team of multi-disciplinary experts led by Professor Chan Chi-hou, Chair Professor in the Department of Electrical Engineering and Director of the State Key Laboratory of Terahertz and Millimeter Waves, is developing high-power THz sources using integrated circuits and optoelectronic approaches, and exploring various applications of THz technology, including for food safety.
To enhance the radiation efficiency of THz source, the team is developing high-performance antennas in the terahertz spectrum and synthesizing high-quality nanowires to generate THz sources through down-conversion. “We can apply compact, low-cost THz sources in different ways,” said Professor Chan. “For instance, the antennas we develop can be used to generate THz and for 6G wireless communications.”
The team is also exploring THz applications in spectroscopy and imaging for addressing health related issues. Many studies show that the absorption of THz radiation by cancer and normal tissues is different, and the team is investigating whether THz imaging can reveal the cancerous parts of tissues more precisely and the changes of the tumour cells for drug testing; and whether THz can be used as a spectroscopic tool for tracing compounds inside tissues for cancer drug development.
Data-driven management for safe and reliable railway systems
As high-speed rail and metro systems are rapidly developing in speed and complexity in many cities and regions, identifying effective ways to ensure their safe, reliable and efficient operation has become more pertinent. A multi-disciplinary research project led by CityU has developed a platform of tools to improve safety and reliability in railway system health monitoring, crowd safety and disruption management.
One of their key studies is the design of a novel domain-knowledge-guided data-driven framework to monitor and predict the health status of high-speed rail suspension systems by measuring real-time train vibration signals from sensors installed in multiple locations. The team proposed a model that can be trained quickly and adapted easily to different rail systems. It includes a feature extraction method, based on a simple dynamics model, to select the relevant information in the multi-location vibration data. Also, it introduces a novel way to generate training datasets via a simple dynamic model and impact analysis.
The research team expects the leading edge technologies developed to not only contribute to safety and revenue management for inter- and intracity rail systems, but also serve as a prototype that can be transferred to other complex network systems, such as shipping, air traffic, electricity transmission, health care systems, supply chain management, internet connectivity and finance.
