title: A comparative study of nozzle/diffuser micropumps with novel valves.
abstract: This study conducts an experimental study concerning the improvement of nozzle/diffuser micropump design using some novel no-moving-part valves. A total of three micropumps, including two enhancement structures having two-fin or obstacle structure and one conventional micro nozzle/diffuser design, are made and tested in this study. It is found that dramatic increase of the pressure drops across the designed micro nozzles/diffusers are seen when the obstacle or fin structure is added. The resultant maximum flow rates are 47.07 mm³/s and 53.39 mm³/s, respectively, for the conventional micro nozzle/diffuser and the added two-fin structure in micro nozzle/diffuser operated at a frequency of 400 Hz. Yet the mass flow rate for two-fin design surpasses that of conventional one when the frequency is below 425 Hz but the trend is reversed with a further increase of frequency. This is because the maximum efficiency ratio improvement for added two-fin is appreciably higher than the other design at a lower operating frequency. In the meantime, despite the efficiency ratio of the obstacle structure also reveals a similar trend as that of two-fin design, its significant pressure drop (flow resistance) had offset its superiority at low operating frequency, thereby leading to a lesser flow rate throughout the test range.
authors.affiliation: Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan. ksyang@itri.org.tw
authors.forename: Kai-Shing
authors.initials: KS
authors.lastname: Yang
authors.forename: Tzu-Feng
authors.initials: TF
authors.lastname: Chao
authors.forename: Ing Youn
authors.initials: IY
authors.lastname: Chen
authors.forename: Chi-Chuan
authors.initials: CC
authors.lastname: Wang
authors.forename: Jin-Cherng
authors.initials: JC
authors.lastname: Shyu
mesh_terms: D004058:Diffusion; D004867:Equipment Design / Q000295:instrumentation* / Q000379:methods*; D015918:Infusion Pumps, Implantable; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*; D011312:Pressure