TechTalk

Young Scholar TechTalk – Customizable Acoustic Metamaterials on Frequency and Spatial Dimensions

Innovation Wing Two, TechTalk / By

March 12 2024 (Tuesday) 4:30-5:30pm
Acoustic metamaterials are artificially designed structured ‘atoms’. Initially, scientists discovered that these meta-atoms can exhibit extraordinary properties beyond those found in natural materials, such as negative density and negative modulus, through localized resonance, which sparked significant interest in the academic community. Subsequently, it was confirmed that these unique narrow-band frequency responses can be extended to broadband impedance designs, leading directly to the emergence of absorption metamaterials and opening up large-scale applications in noise reduction. In recent years, the potential of customizable metamaterials has gradually been realized. We will present our latest works from two complementary perspectives: customized frequencies and spatial non-uniformity, which may open up new applications such as directional emission, stealth cloaking and automotive acoustics.

TechTalk – Device-Independent Quantum Key Generation

Innovation Wing Two, TechTalk / By

March 7 2024 (Thursday) 4:30-5:30pm
The extraction of private, uniformly random bits from weakly random seeds is a problem of central importance in cryptography with multiple applications. A well-known result in classical computer science states that randomness extraction is possible using classical resources only when multiple independent sources are available. On the other hand, Quantum Entanglement enables a solution to the problem even in the so-called device-independent framework. Device-Independent quantum cryptography offers the highest form of security, wherein the users do not need to even trust the devices executing the cryptographic protocol, and can instead verify correctness and security by means of simple statistical tests on the devices. In this talk, we report on the state-of-art theoretical and experimental results on device-independent quantum cryptography, with a focus on quantum randomness amplification and quantum key distribution.

TechTalk – Nature-Inspired Fluidics

Innovation Wing Two, TechTalk / By

February 29 2024 (Thursday) 4:30-5:30pm
Fluids are ubiquitous in nature and transport of fluids plays an essential role in sustaining many activities across multiple scales. The mode of fluidic transport therefore also spans multiple length scales. Moreover, despite largely aqueous in nature, natural fluids exhibit complexity, dynamics and structures that have yet to be replicated synthetically. In this talk, I will share our works in designing approaches to form, manipulate and direct aqueous solutions. In particular, I will focus on unique properties of aqueous multiphase systems that may serve as model systems for understanding their natural counterparts. I will conclude by discussing how these systems can potentially inspire biomimetic and biomedical applications.

TechTalk – Unlock the Hidden Value of Bridges’ Reserve Capacity in Toll Highway Operation

Innovation Wing Two, TechTalk / By

February 22 2024 (Thursday) 4:30-5:30pm
The extra reserve capacity exists widely in highway bridges due to the conservative design and construction. In a case study of a highway flyover in Singapore, the flyover still possesses at least an additional 30% loading capacity after twenty years of operation. This additional capacity, which was achieved by consuming extra raw materials and energy when the bridge was built years ago, is considered another kind of “waste” since it has never been used. To make use of it, the speaker introduced the additional loading capacity into the framework of operating profit optimization. The unused loading capacity enables a higher volume of vehicles and a higher proportion of heavy vehicles, thus further leading to the increase in toll profit.

TechTalk – Health Care Applications with Natural Language Processing

Innovation Wing Two, TechTalk / By

April 5 2024 (Friday) 4:30-5:30pm
Unstructured documents often come with embedded structured data. Representing valuable and structured information as tables is popular in health, financial, and many domains. However, manual extraction of structured information from documents typically costs tremendous time and labor, motivating the need for a system for automating the process. After such tables have been extracted, the data can be used for a wide variety of tasks such as question answering and various “down-stream” analytics tasks. In this talk, we will discuss how to leverage ground breaking pre-trained language models (e.g., BERT, ChatGPT) to develop tools for automated table extraction from various types of documents. We will present different applications from cancer registry reporting, cancer care, and psychiatry hospitalization prediction.

TechTalk – (Cancelled) Technology for Bioelectronic Medicine

Innovation Wing Two, TechTalk / By

February 2 2024 (Friday) 2:30-3:30pm
Neurological conditions affect one in six people, imposing significant health, economic and societal burden. Bioelectronic medicine aims to restore or replace neurological function with the help of implantable electronic devices. Unfortunately, significant technological limitations prohibit these devices from reaching patients at scale, as implants are bulky, require invasive implantation procedures, elicit a pronounced foreign body response, and show poor treatment specificity and off-target effects. Over the past decade, new devices made using methods from microelectronics industry have been shown to overcome these limitations. Recent literature provides powerful demonstrations of thin film implants that are miniaturised, ultra-conformal, stretchable, multiplexed, integrated with different sensors and actuators, bioresorbable, and minimally invasive. I will discuss the state-of-the-art of these new technologies and the barriers than need to be overcome to reach patients at scale.

HKAES TechTalk – How clean is the air we breathe in urban areas?

Innovation Wing Two, TechTalk / By

February 20 2024 (Tuesday) 4:00-5:00pm
Air pollution continues to cause significant environmental health risks, leading to numerous premature deaths worldwide each year. To protect public health, many governments have implemented regulatory policies on mass concentration of major air pollutants, referencing the guideline values recommended by the World Health Organization (WHO). However, new scientific evidence suggests various components in the air have different health effects. This talk will share research findings on the key toxic components of urban air from both chemical and biological aspects and their associated emission sources responsible for health effects.

TechTalk – Seawater Sea-sand Engineered Cementitious Composites (SS-ECC) for Marine and Coastal Infrastructures

Innovation Wing Two, TechTalk / By

January 25 2024 (Thursday) 4:30-5:30pm
Engineered/Strain-Hardening Cementitious Composites (ECC/SHCC) is an advanced fiber-reinforced concrete exhibiting multiple-cracking and strain-hardening under tension. We aimed to explore the feasibility of producing high-strength seawater sea-sand Engineered Cementitious Composites (SS-ECC) for marine and coastal applications facing the shortage of freshwater and river/manufactured sand. The effects of key composition parameters including the sea-sand size, the polyethylene fiber length, and the fiber volume dosage on the mechanical performance of SS-ECC were comprehensively investigated. The crack characteristics of SS-ECC were also assessed and modelled, which are critical for its applications with non-corrosive reinforcements. SS-ECC with tensile strength over 8 MPa, ultimate tensile strain of about 5%, and compressive strength over 130 MPa were achieved. Using seawater and sea-sand had almost no negative effects on the 28-day mechanical properties of high-strength ECC. Smaller sand size and higher fiber dosage of SS-ECC resulted in smaller crack widths under the same tensile strain. A five-dimensional representation was proposed to assess the overall performance of SS-ECC, by comprehensively considering both the crack characteristics and the mechanical properties. A probabilistic model was also proposed to describe the stochastic nature and evolution of crack width, and it can be used to estimate the critical tensile strain on SS-ECC for a given crack-width limit and cumulative probability. The findings and proposed methods can facilitate the design of SS-ECC in marine and coastal infrastructures.

TechTalk – Insights on the Future Development of Engineering and Technologies in China

Innovation Wing Two, TechTalk / By

Speaker: Academician C.C. Chan, Honorary Professor, The University of Hong Kong, Distinguished Chair Professor, Hong Kong Polytechnic University, Academician, Chinese Academy of Engineering, Fellow, Royal Academy of Engineering   About the TechTalk We would like to extend our sincere gratitude and appreciation to Academician C.C. Chan for sharing with us two videos of his speech on …

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HKAES TechTalk – Living with Climate Extremes – Hong Kong Perspective

Innovation Wing Two, TechTalk / By

January 23 2024 (Tuesday) 4:00-5:00pm
Hong Kong has a sub-tropical climate and wide variety of weather. Different extreme weather events, including tropical cyclone, heavy rain, and extreme temperatures, can affect Hong Kong and result in significant impacts to the society. Looking into the future, against the background of climate change and local urbanization, Hong Kong will expect even warmer climate, more variable rainfall, more intense typhoons, and a sea level that keeps rising in the coming centuries. This may affect the frequency and severity of various extreme weather and increase the risk of related weather hazards. This presentation will review different kinds of high impact extreme weather in Hong Kong and their past trend and future projection. Moreover, a brief overview on the concept of climate risk management will be shared.