Development of active breathing micro PEM fuel cell

Mechanical Systems and Signal Processing

Tran

et al. 2018

In this paper, we report a further study of flow-network generating four jet flows which circulate in a sealed device to experimentally investigate the feasibility and efficiency of a dual-axis gyroscope. The experiment is carried out successfully and the experimental results reasonably agreed with those obtained by numerical analysis using OpenFOAM. The flow rectifying coefficient is determined using the mathematical lump model for a vibrating system, which takes into account of the device geometry and resonant frequency. Experimental and numerical results demonstrate that the coefficient of the new system developed in this study is significantly higher than those of conventional designs. The hotwire-integrated device which can function as a dual-axis gyroscope is tested using a turntable with speeds up to 1900 rpm. The scale factor and cross-sensitivity of the system are 0.26 μVs/° and 1.2 %, respectively. The cross-sensitivity and the effects of linear acceleration, actuating voltage on the diaphragm, heating power and position of hotwires are also investigated.

Section: Letmentioning

confidence: 99%

Fluidic mechanism for dual-axis gyroscope

Dau

Mechanical Systems and Signal Processing

Tran

et al. 2018

“…As we know, flow in a closed system possesses several advantages, such as independence from the contamination by environmental variations [10]- [14]. With the introduction of flow circulating in a confined space, the integration and miniaturization of measuring systems enhance the capability and impact of microfluidic systems [15]- [17]. The flow in a confined space has been applied in the inertial sensing and particularly the angular rate sensing where the presence of a self-contained valveless micro-pump reduces the risk of damage to mechanical counterparts [18]- [27].…”

Section: Introductionmentioning

confidence: 99%

Vortex flow generator utilizing synthetic jets by diaphragm vibration

Dau

International Journal of Mechanical Sciences

Bui

et al. 2018

This paper develops a millimeter scale fully packaged device in which a vortex flow of high velocity is generated inside a chamber. Under the actuation by a lead zirconate titanate (PZT) diaphragm, a flow circulates with increasing velocity after each actuating circle to form a vortex in a cavity named as the vortex chamber. At each cycle, the vibration of the PZT diaphragm creates a small net air flow through a rectifying nozzle, generates a synthetic jet which propagates by a gradual circulation toward the vortex chamber and then backward the feedback chamber. The design of such device is firstly conducted by a numerical analysis whose results are considered as the base of our experimental setup. A vortex flow generated in a chamber of the device (named as the votex chamber) was observed by a high-speed camera. The present approach which was illustrated by both the simulation and experiment is potential in various applications related to the inertial sensing, fluidic amplifier and micro/nano particle trapping and mixing.

“…As we know, flow in a closed system possesses several advantages, such as minimizing the number of analyzed samples and partial/complete freedom from the contamination by environmental variations [9]- [13]. With the introduction of circulatory flow, the integration and miniaturization of measuring systems significantly enhance the capability and impact of microfluidic systems [14]- [16]. The circulatory flow in a confined space is applied mostly in the inertial sensing and particularly angular rate sensing where the advantage of a selfcontained valveless micro-pump reduces the risk of damage to mechanical counterparts [17]- [26].…”

Section: Introductionmentioning

confidence: 99%

A Closed Device to Generate Vortex Flow Using PZT

Bui

2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS)

Phan

et al. 2018

This paper reports for the first time a millimeter scale fully packaged device which generates a vortex flow of high velocity. The flow which is simply actuated by a PZT diaphragm circulates with a higher velocity after each actuating circle to form a vortex in a desired chamber. The design of such device is firstly conducted by a numerical analysis using OpenFOAM. Several numerical results are considered as the base of our experiment where a flow vortex is observed by a high speed camera. The present device is potential in various applications related to the inertial sensing, fluidic amplifier and micro/nano particle trapping and mixing.