title: Atomization of High-Viscosity Fluids for Aromatherapy Using Micro-heaters for Heterogeneous Bubble Nucleation.
abstract: The development of a novel lead-free microelectromechanical-system (MEMS)-based atomizer using the principle of thermal bubble actuation is presented. It is a low-cost, lead-free design that is environmentally friendly and harmless to humans. It has been tested to be applicable over a wide range of fluid viscosities, ranging from 1 cP (e.g., water) to 200 cP (e.g., oil-like fluid) at room temperature, a range that is difficult to achieve using ordinary atomizers. The results demonstrate that the average power consumption of the atomizer is approximately 1 W with an atomization rate of 0.1 to 0.3 mg of deionized (DI) water per cycle. The relationships between the micro-heater track width and the track gap, the size of the micro-cavities and the nucleation energy were studied to obtain an optimal atomizer design. The particle image velocimetry (PIV) results indicate that the diameter of the ejected droplets ranges from 30 to 90 μm with a speed of 20 to 340 mm/s. In addition, different modes of spraying are reported for the first time. It is envisioned that the successful development of this MEMS-based atomizing technology will revolutionize the existing market for atomizers and could also benefit different industries, particularly in applications involving viscous fluids.
authors.affiliation: Department of Mechanical and Biomedical Engineering, The City University of Hong Kong, Kowloon Tong, Hong Kong.
authors.forename: Junhui
authors.initials: J
authors.lastname: Law
authors.affiliation: Department of Mechanical and Biomedical Engineering, The City University of Hong Kong, Kowloon Tong, Hong Kong.
authors.forename: Ka Wai
authors.initials: KW
authors.lastname: Kong
authors.affiliation: Department of Mechanical and Biomedical Engineering, The City University of Hong Kong, Kowloon Tong, Hong Kong.
authors.forename: Ho-Yin
authors.initials: HY
authors.lastname: Chan
authors.affiliation: Department of Mechanical and Biomedical Engineering, The City University of Hong Kong, Kowloon Tong, Hong Kong.
authors.forename: Winston
authors.initials: W
authors.lastname: Sun
authors.affiliation: Department of Mechanical and Biomedical Engineering, The City University of Hong Kong, Kowloon Tong, Hong Kong.
authors.forename: Wen Jung
authors.initials: WJ
authors.lastname: Li
authors.affiliation: Acoustic Arc International Limited, Science Park, Shatin, Hong Kong.
authors.forename: Eric Boa Fung
authors.initials: EB
authors.lastname: Chau
authors.affiliation: Acoustic Arc International Limited, Science Park, Shatin, Hong Kong.
authors.forename: George Kak Man
authors.initials: GK
authors.lastname: Chan
mesh_terms: D019341:Aromatherapy; D006358:Hot Temperature; D007091:Image Processing, Computer-Assisted; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D013500:Surface Tension; D014783:Viscosity