A PZT Micropump With Planar Passive Valves and its Flow Measurements

2009 ◽  
Author(s):  
Chia-Jui Hsu ◽  
Horn-Jiunn Sheen

In this paper, a simply-designed reciprocating-type micropump is presented. We also report the coupling effects between the valve motion and the flow behaviors, which were studied using a micro-PIV technique. The fluids were easily driven by a PZT plate and net flow was directed toward the outlet after rectification by two planar passive valves. The results revealed that good pumping performance was obtained even at a low excitation voltage of 10V. The optimum flow rate was measured at a frequency of 0.8kHz and the maximum flow rate was 275μl/min at 30V. The micropump was uniquely characterized by the existence of a linear relationship between the flow rate and the driving frequency, which enabled this micropump to be easily operated and controlled. The experimental results showed that the micropump was reliable in terms of the high linearity and repeatability, which is very favorable for portable microfluidic systems. The micro-PIV measurements of the transient motions of the valve and the flow behaviors clearly revealed that the valve efficiency depended on the mass inertia of the moving part, excitation frequency, and voltage. The present results are useful for the optimum design of this planar passive valve to improve the pumping efficiency.

Author(s):  
Jangmi Woo ◽  
Yeonghyeon Gim ◽  
Dong Kee Sohn ◽  
Han Seo Ko

Abstract Recent developments of smart materials such as piezo devices have been applied to small hydraulic pumps, enabling to meet various demands. For the compact pump, the valves are critical components in the aspect of fluid dynamics. In this study, the flow inside the reed valve port driven by the piezo actuator was experimentally observed. When a sine wave with a driving frequency of 90 Hz was applied, the maximum flow rate could be obtained. It was found that the developed flow opposite to the outlet direction at the root portion of the valve prevented further increase of the flow rate according to the operating frequency.


2009 ◽  
Vol 3 (2) ◽  
Author(s):  
Y. Zhou ◽  
F. Amirouche ◽  
L. Chen

Micropump, an actuation source to transfer the fluid from reservoir to the target place with accuracy and reliability, plays an important role in microfluidic devices. A broad range of micropump applications in biomedical fields are found in the fluid fine regulation and precise control systems for implantable drug delivery, chemical and biological detection, as well as blood transport in cardiology system. A polydimethylsiloxane (PDMS) magnetic composite membrane based on microfabrication with dimensions of 6 mm and 65 μm in diameter and thickness respectively, is employed to actuate a proposed micropump. In micro pumping operation, the fluid flow effects on the actuation and dynamic response of an oscillating membrane are curial to the design of the micropump. Therefore, the resonant frequency of this micro device is estimated considering the added mass and fluid damping to understand the behaviors of the valveless micropump. In this study, the membrane actuation is implemented by a miniaturized electromagnet, which provides an external time-varying magnetic field. The magnetic force on the membrane is proportional to the gradient of the magnetic field and the magnetization of the micro particles embedded in the membrane. The alternating attractive and repulsive magnetic forces on this composite membrane are computed by Finite Element Analysis (FEA). The basic design issues of the electromagnetic actuator involving air gaps, input current signals, and distribution of magnetic flux in the magnetic circuit are presented. Moreover, the magnetic-structure coupling analysis is conducted to determine the maximum deformation and stresses on the membrane, which result from the action of these magnetic forces. Finally, frequency-dependent flow rate of a dual-chamber configuration micropump has been studied. The pumping rate increases almost linearly with the excitation frequency at low ranges and there exists resonant frequencies at which the flow rate will reach a maximum value. After the flow rate peaks, the pumping rate decreases sharply along with the actuating frequencies. The maximum flow rate for the dual-chamber remains at 27.73μl/min under 0.4 A input current with an excitation frequency of 3 Hz. For comparison, a single-chamber micropump reaches a maximum flow rate of 19.61μl/min with a resonant frequency of 4.36 Hz under the same condition.


2021 ◽  
Vol 894 (1) ◽  
pp. 012018
Author(s):  
H Gabrielle ◽  
R A Kusumadewi ◽  
Ratnaningsih

Abstract To provide drinking water in Bogor Regency, PDAM Tirta Kahuripan has several Water Treatment Plants (WTP) Kedung Halang WTP. Kedung Halang WTP consists of two water treatment packages, Indisi and Degreemont, with an average production of 37.3 L/s and 83.9 L/s, respectively. The purposes of this research are to evaluate the performance of the operating unit and process on the Degreemont Package and to provide optimisation recommendations based on the evaluation result. Steps in this research include evaluating the existing condition, providing recommendations, and analysing the quality of water produced. The evaluation found that one of the parameters did not fulfil the design criteria: the G.Td value on coagulation. The evaluation result of maximum flow rate is 125 L/s on intake, 150 L/s on coagulation, 130 L/s on flocculation and sedimentation, and 200 L/s on filtration. Thus, the optimum flow rate that can be operated is 125 L/s. The turbidity of the water produced has met the drinking water standard according to Minister of Health Regulation No. 492 of 2010, with removal efficiency above 95%. According to the result, it can be said that Degreemont Package is qualified to be applied as a drinking water treatment.


Author(s):  
Mai Yu ◽  
Song Chen ◽  
Jun Wu Kan ◽  
Zhong Hua Zhang ◽  
Chao Ping Qian ◽  
...  

A miniature piezomembrane hydraulic pump with decreasing chambers in succession (PHPDCS) is presented. The number of chambers in PHPDCS decreases successively in two serial stages. The first stage consists of two chambers in parallel while the second stage consists of only one chamber. The proposed PHPDCS has the comprehensive advantages of serial and parallel connection of multi-chamber and has a high energy conversion efficiency. The prototype of PHPDCS is designed and manufactured. The output performance of PHPDCS under different external loads is investigated by experiments. Experimental results indicate that the optimum flow rate of the proposed PHPDCS is obtained when phase difference between two serial stages is 180°. The output performance of PHPDCS is superior to that of traditional piezoelectric pumps with two chambers in serial (PPCS). At 50 Hz, the maximum flow rate of PHPDCS under external load of 5 kPa is more than twice as high as that of PPCS. Under the external load of 10 kPa, the maximum flow rate of PHPDCS reaches 6.87 mL/min, whereas PPCS has no flow rate output.


Author(s):  
Song Chen ◽  
Zhen He ◽  
Chaoping Qian ◽  
Jianping Li ◽  
Zhonghua Zhang ◽  
...  

A piezoelectric micro gas compressor with parallel-serial hybrid chambers (PMGCPS) is presented, which consists of two compression stages of stage I and stage II. The stage I is composed of two piezoelectric driving units connected in parallel, while stage II is composed of a piezoelectric driving unit, forming an integral tower compression structure. Based on the tower compression structure, the PMGCPS owns the dual advantages of large flow rate and high output pressure. The prototype of PMGCPS is designed and manufactured. The driving frequency and voltage characteristics of PMGCPS are experimented. Under the driving frequency of 300 Hz and the driving voltage of 300 Vpp, the maximum flow rate and output pressure of PMGCPS is 795.6 mL/min and 13.4 kPa, respectively. PMGCPS provides new ideas for the further development of piezoelectric micro gas compressor.


2020 ◽  
Vol 19 (2) ◽  
pp. 64-68
Author(s):  
Mrinmoy Biswas ◽  
Sudip Das Gupta ◽  
Mohammed Mizanur Rahman ◽  
Sharif Mohammad Wasimuddin

Objective: To assess the success of BMG urethroplasty in long segment anterior urethral stricture. Method: From January 2014 to December 2015, twenty male patients with long anterior segment urethral stricture were managed by BMG urethroplasty. After voiding trial they were followed up at 3 month with Uroflowmetry, RGU & MCU and PVR measurement by USG. Patients were further followed up with Uroflowmetry and PVR at 6 months interval.Successful outcome was defined as normal voiding with a maximum flow rate >15ml /sec and PVR<50 ml with consideration of maximum one attempt of OIU after catheter removal. Results: Mean stricture length was 5.2 cm (range 3-9 cm) and mean follow-up was 15.55 months (range 6-23 months). Only two patients developed stricture at proximal anastomotic site during follow-up. One of them voided normally after single attempt of OIU. Other one required second attempt of OIU and was considered as failure (5%). Conclusion: BMG urethroplasty is a simple technique with good surgical outcome. Bangladesh Journal of Urology, Vol. 19, No. 2, July 2016 p.64-68


2006 ◽  
Vol 26 (Supplement2) ◽  
pp. 237-240
Author(s):  
Sinzaburo UMEDA ◽  
Shinji SHIGEYAMA ◽  
Wen-Jei YANG

2021 ◽  
Vol 62 (8) ◽  
Author(s):  
Lionel Hirschberg ◽  
Friedrich Bake ◽  
Karsten Knobloch ◽  
Angelo Rudolphi ◽  
Sebastian Kruck ◽  
...  

AbstractMeasurements of sound due to swirl–nozzle interaction are presented. In the experiment a swirl structure was generated by means of unsteady tangential injection into a steady swirl-free flow upstream from a choked convergent–divergent nozzle. Ingestion of swirl by the choked nozzle caused a mass-flow rate change, which resulted in a downstream-measured acoustic response. The downstream acoustic pressure was found to remain negative as long as the swirl is maintained and reflections from the open downstream pipe termination do not interfere. The amplitude of this initial acoustic response was found to be proportional to the square of the tangential mass-flow rate used to generate swirl. When the tangential injection valve was closed, the mass-flow rate through the nozzle increased, resulting in an increase of the downstream acoustic pressure. This increase in signal was compared to the prediction of an empirical quasi-steady model, constructed from steady-state flow measurements. As the opening time of the valve was varied, the signal due to swirl evacuation showed an initial overshoot with respect to quasi-steady behavior, after which it gradually decayed to quasi-steady behavior for tangential injection times long compared to the convection time in the pipe upstream of the nozzle. This demonstrates that the acoustic signal can be used to obtain quantitative information concerning the time dependence of the swirl in the system. This could be useful for understanding the dynamics of flow in engines with swirl-stabilized combustion. Graphic abstract


Author(s):  
Yuchuan Zhu ◽  
Chang Liu ◽  
Yunze Song ◽  
Long Chen ◽  
Yulei Jiang ◽  
...  

In this paper, an electro-hydrostatic actuator driven by dual axial-mounted magnetostrictive material rods-based pumps (MMPs) with a new type of active rectification valve is designed in the current study. Based on flow distribution of the active rectification valve and driving energy provided by two MMPs, the actuator can output continuous and bidirectional displacement. By establishing a mathematical model of the actuating system, using simulation techniques, the change rule of hydraulic cylinder’s motion state caused by different driving signals are studied and analyzed. Test equipment platform is constructed in the laboratory to test the output characteristics and confirm the feasibility of the new concept. The experimental results indicate that the maximum flow rate can reach approximately 2.7 L·min−1, while the operating frequency is 180 Hz.


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