Hing Wah Lee

Internal combustion engine (ICE) vehicles are major contributors to climate change and pollution, driving the transition to electric vehicles (EVs) as a cleaner alternative. However, EVs encounter challenges with charging infrastructure, notably the need for physical cables and issues with alignment for efficient charging. To address these problems, a wireless EV charging system has been developed using internet of things (IoT) technology for real-time monitoring and control. This system incorporates ESP32 and ESP8266 microcontrollers, infrared sensors, inductive coils, an OLED display, an ESP32-CAM module, relay modules, an AC to DC converter, a TP4056 charging module, a DC voltage sensor, and lithium-ion batteries. It employs a 20-turn coil for inductive coupled wireless power transfer (WPT), enabling the full charging of two lithium-ion batteries within 60 minutes. The system can detect an EV’s presence, display battery status on an OLED screen, and provide real-time images of the vehicle’s position through the SWEVCS mobile app. Infrared sensors ensure proper and precise alignment for effective charging. This advanced wireless charging solution enhances EV charging efficiency and convenience while supporting a more sustainable energy approach.

Due to the challenging dispersion of graphene in aqueous media, organic solvents are commonly used in conductive graphene inks. This will result in safety issues and environmental pollution. In this study, we demonstrated a green approach of graphene ink preparation through one-pot synthesis reaction that produce a hybrid reduced graphene oxide (rGO)-silver nanoparticles (AgNPs), with deionized water as solvent. The synthesized rGO-AgNPs was monitored using ultraviolet–visible (UV-Vis) spectroscopy and fourier transform infrared (FTIR). A stable dispersion of rGO-AgNPs ink was confirmed through UV-Vis analysis. FTIR result showed the removal and the reduction in the intensities of absorption bands of oxygen-containing functional groups, which indicated that graphene oxide (GO) has been successfully reduced to rGO in the hybrid ink. The printed film of rGO-AgNPs exhibited a high conductivity of 1.50 × 10⁴ S/cm, proven that the electrical performance of the hybrid ink has been improved as compared to previously reported GO-based ink. Printed into interdigitated electrode (IDE), the impressive characteristic of our hybrid ink performed well as a high-sensitivity flexible humidity sensor.

Kinetic-oriented design of ZnIn₂S₄via P-filling can modulate the surface activity by diminishing H adsorption–desorption barrier for sacrificial-free H₂ evolution.

In this research, a flexible inkjet-printed temperature sensor with in-house silver nanoparticles ink is presented and compared with the sensor printed with commercial silver nanoparticles ink. These sensors have an average width of 0.5 ± 0.04 mm in the latter and 0.5 ± 0.03 mm in the former. These serpentine-structure sensors were printed on polyethylene terephthalate (PET) substrate by using a Fujifilm Dimatix 2850 printer. The corresponding results indicating resistance have been recorded in the range of 30–100 °C to evaluate the sensor performance. The result of the studies showed that there was a linear relationship between the resistance and temperature for both ink types. The printed sensors developed using the in-house ink presented higher sensitivity, 0.1086 Ω/°C, compared to the commercial ink, which was 0.0543 Ω/°C. Therefore, the flexible inkjet-printed temperature sensor with the in-house silver nanoparticles ink is recommended for the large-scale productions and implementations.

In recent years, the field of nanophotonics has progressively developed. However, constant demand for the development of new light source still exists at the nanometric scale. Light emissions from graphene-based active materials can provide a leading platform for the development of two dimensional (2-D), flexible, thin, and robust light-emitting sources. The exceptional structure of Dirac’s electrons in graphene, massless fermions, and the linear dispersion relationship with ultra-wideband plasmon and tunable surface polarities allows numerous applications in optoelectronics and plasmonics. In this article, we present a comprehensive review of recent developments in graphene-based light-emitting devices. Light emissions from graphene-based devices have been evaluated with different aspects, such as thermal emission, electroluminescence, and plasmons assisted emission. Theoretical investigations, along with experimental demonstration in the development of graphene-based light-emitting devices, have also been reviewed and discussed. Moreover, the graphene-based light-emitting devices are also addressed from the perspective of future applications, such as optical modulators, optical interconnects, and optical sensing. Finally, this review provides a comprehensive discussion on current technological issues and challenges related to the potential applications of emerging graphene-based light-emitting devices.

This is a prospective randomized, controlled study of patients suffering from anxiety, depression, or mixed anxiety-depressive disorder attending a hypnotherapy clinic for 8 weeks. Participants were assessed with various clinical scales and randomly assigned to either the study or control group. The study group received 5 to 7 sessions of hypnotherapy through the 8-week period, whereas the control group received conventional psychiatric treatment. All patients’ clinical conditions were reassessed at the end of the 8th week. Comparing study and control groups at the end of the 8th week, there was improvement in the study group in the scores of an array of clinical scales. Such satisfactory results illustrate the effectiveness of hypnotherapy in relieving anxiety and depressive symptoms.

A 2D–2D p–n junction heterointerface is formulated through the synergetic dual doping of boron-doped rGO and oxygen-doped gC ₃ N ₄ .