Research Highlight – Innovation Wing

Hybrid Assembly of Polymeric Nanofiber Network for Robust and Electronically Conductive Hydrogels

Hydrogels are promising candidate materials for the construction of soft electronics and biomedical devices due to their mechanical flexibility, structural permeability, and biocompatibility. However, achieving high electrical conductivity and mechanical robustness in hydrogels remains challenging, which limits their practical applications.
Professor Lizhi Xu’s research team has developed a new type of electroconductive hydrogels with outstanding mechanical strength and manufacturability.

A Self-rotating, Single-actuated UAV with Extended Sensor Field of View for Autonomous Navigation

The UAV is named Powered-flying Ultra-underactuated LiDAR-sensing Aerial Robot (PULSAR), whose motion in three-dimensional space is controlled by only a single actuator (i.e., motor). The single actuator design can naturally cause self-rotation motion of the UAV body, obviously extending the field of view (FoV) of the onboard LiDAR sensor. Furthermore, it also effectively reduces the energy loss of the propulsion system, allowing PULSAR to save 26.7% of energy consumption compared to a benchmarked quadrotor UAV. Utilizing the extended FoV and onboard computing resource, PULSAR can perform autonomous navigation in unknown environments and detect both static and dynamic obstacles in panoramic views without using any external instruments. PULSAR has large FoV, high flight efficiency, and autonomous navigation ability, which are all beneficial for the environmental observation and information collection. Therefore, it can be used in various applications, such as environment surveying, search and rescue, terrain mapping, and automatic 3D reconstruction.

Self-powered Multimodal Smart Skin Enabled by Triboelectricity and Hygroelectricity

Innovation Wing Two, Third exhibition / By cheukky

Tactile e-skins mimicking functions of human skin can sense tactile modalities such as pressure, vibration, temperature, and humidity. They are essential components for smart robotics, health monitoring devices and human–machine interfaces.
However, complicated materials, sophisticated manufacturing, device integration and external power sources are required for most of existing multi-functional e-skins, which severely limit their widespread use.

Ultrastrong and multifunctional aerogels with hyperconnective network of composite polymeric nanofiber

Innovation Wing Two, Third exhibition / By cheukky

Aerogels are lightweight materials with extensive microscale pores, which could be used in thermal insulation, energy devices, aerospace structures, as well as emerging technologies of flexible electronics. However, traditional aerogels based on ceramics tend to be brittle, which limits their performance in load-bearing structures. Due to restrictions posed by their building blocks, recently developed classes of polymeric aerogels can only achieve high mechanical strength by sacrificing their structural porosity or lightweight characteristics.

On-Demand, Direct Printing of Nanodiamonds at the Quantum Level

Innovation Wing Two, Second exhibition / By cheukky

Practical realization of quantum devices calls for the placement of individual qubits on complex nanophotonic circuits. However, this prerequisite continues to suffer from coarse positioning accuracy, low throughput, and process complexity. We developed a novel nanoprinting scheme that allows the controllable placement of nitrogen-vacancy (NV) center nanodiamonds at the quantum level. The scheme enables remarkable achievements that are not attainable by other approaches: (1) single-quantum level quantity control, (2) sub-wavelength positional accuracy, and (3) scalable, ‘lithography-free’ patterning capability. We believe this work to be a game-changer, as it directly addresses the key technological challenge associated with the realization of quantum devices. The patent for this invention has been filed (US 63/236,411, PCT Application No. PCT/CN2022/113516).

A Doubling of Annual Tropical Forest Carbon Loss Driven by Agricultural Expansion

Innovation Wing Two, Second exhibition / By cheukky

Tropical forests are the largest terrestrial component of the global carbon cycle, storing about 250 Giga tons (Gt) biomass carbon in their woody vegetation and absorbing ~70 Gt CO2 per year through photosynthesis. Loss of forests could be devastating because not only the stored carbon stocks in biomass and soil are losing but also the function of sequestering atmospheric carbon.

High-voltage Aqueous Mg-ion Battery Facilitated by Water-in-salt Electrolyte

Innovation Wing Two, Second exhibition / By cheukky

Although widely used in our daily life, lithium (Li) -ion batteries fall short because the materials used are often scarce, toxic, and expensive. They also have safety issue in operation due to their organic based electrolytes. Beyond lithium-ion batteries, a low-cost magnesium (Mg) metal anode based aqueous Mg-ion battery has been developed first time by Professor Dennis Leung’s research team in the HKU Department of Mechanical Engineering. As Mg is the 5th most abundant metal element in the earth’s crust (three orders of magnitude more than Li), the advantages of low cost and non-toxicity make Mg a desirable alternative to Li as the anode material. The proposed battery shows a high discharge plateau of 2.4-2.0 V and an excellent rechargeability for over 700 stable cycles. This high operation voltage exceeds the counterpart of other multivalent-ion batteries, including zinc (Zn) metal and aluminum (Al) metal batteries. The mechanism behind was also revealed, where a conductive metallic oxide layer was facilitated by the chloride (Cl-) ions inside the water-in-salt electrolyte, providing ionic pathways for rechargeable battery operations. The team hopes that the chemical insights obtained in this work could inspire further optimization and bring attention to the overlooked development of rechargeable aqueous Mg metal batteries. This work uncovers the once dismissed possibility of aqueous Mg metal batteries and opens a new avenue in the field of post-lithium-ion batteries. Other project team members are Dr. Wending Pan (Research Assistant Professor) and Miss Sarah Leong (PhD student).

High-speed Laser-scanning Biological Microscopy using FACED

Innovation Wing Two, Second exhibition / By cheukky

Laser scanning is used in advanced biological microscopy to deliver superior imaging contrast, resolution and sensitivity. However, it is challenging to scale up the scanning speed required for interrogating a large and heterogeneous population of biological specimens or capturing highly dynamic biological processes at high spatiotemporal resolution. Bypassing the speed limitation of traditional mechanical methods, free-space angular-chirp-enhanced delay (FACED) is an all-optical, passive and reconfigurable laser-scanning approach that has been successfully applied in different microscopy modalities at an ultrafast line-scan rate of 1-80 MHz. Optimal FACED imaging performance requires optimized experimental design and implementation to enable specific high-speed applications. In this protocol, we aim to disseminate information allowing FACED to be applied to a broader range of imaging modalities. We provide (i) a comprehensive guide and design specifications for the FACED hardware; (ii) step-by-step optical implementations of the FACED module including the key custom components; and (iii) the overall image acquisition and reconstruction pipeline. We illustrate two practical imaging configurations: multimodal FACED imaging flow cytometry (bright-field, fluorescence and second-harmonic generation) and kHz 2D two-photon fluorescence microscopy. Users with basic experience in optical microscope operation and software engineering should be able to complete the setup of the FACED imaging hardware and software in ~2-3 months.

Biofilm Inhibition in Oral Pathogens by Nanodiamonds

Inaugural exhibition, Innovation Wing Two / By cheukky

Complex microbial communities, e.g., biofilms residing in our oral cavity, have recognized clinical significance, as they are typically the main cause for infections. Diamond nanoparticles, namely, nanodiamonds (NDs) have been demonstrated to work as an effective antibacterial agent against planktonic cells (free-floating state) due to their many promising physico-chemical properties. However, little is known about the behaviors of NDs against biofilms (sessile state).

Soft Robotic Manipulator for Intra-operative MRI-guided Transoral Laser Microsurgery

Inaugural exhibition, Innovation Wing Two / By cheukky

Magnetic resonance (MR) imaging (MRI) provides compelling features for the guidance of interventional procedures, including high-contrast soft tissue imaging, detailed visualization of physiological changes, and thermometry. Laser-based tumor ablation stands to benefit greatly from MRI guidance because 3D resection margins alongside thermal distributions can be evaluated in real time to protect critical structures while ensuring adequate resection margins. However, few studies have investigated the use of projection-based lasers like those for transoral laser microsurgery, potentially because dexterous laser steering is required at the ablation site, raising substantial challenges in the confined MRI bore and its strong magnetic field. Here, we propose an MR-safe soft robotic system for MRI-guided transoral laser microsurgery. Owing to its miniature size (Ø12 × 100 mm), inherent compliance, and five degrees of freedom, the soft robot ensures zero electromagnetic interference with MRI and enables safe and dexterous operation within the confined oral and pharyngeal cavities. The laser manipulator is rapidly fabricated with hybrid soft and hard structures and is powered by microvolume (<0.004 milliter) fluid flow to enable laser steering with enhanced stiffness and lowered hysteresis. A learning-based controller accommodates the inherent nonlinear robot actuation, which was validated with laser path-following tests. Submillimeter laser steering accuracy was demonstrated with a mean error < 0.20 mm. MRI compatibility testing demonstrated zero observable image artifacts during robot operation. Ex vivo tissue ablation and a cadaveric head-and-neck trial were carried out under MRI, where we employed MR thermometry to monitor the tissue ablation margin and thermal diffusion intraoperatively.