Fluidic Capacitive Sensor for Detection of Air Bubble Inside Engine Lubricating Oil
Main Article Content
Abstract
In this paper, a capacitive sensor based on printed circuit board was designed and fabricated to detect air bubbles that appear in the engine lubricating oil. A three-electrode capacitive sensor structure is designed and simulated for monitoring and estimating amount and size of air bubbles in oil. The capacitive sensor consists of three electrodes that are structured by the PCB, copper sheets and vias. The oil pipe as a fluidic channel is threaded through the hole of capacitive sensor. By using that structure, air bubble inside fluidic channel can be detected in real-time monitoring. Simulations showing the change of signal in correspondence to the volume of air bubble inside oil channels are compared to the measurement to give a good idea of fabrication structure. In this measurement, this capacitive sensor can monitor an air bubble with a small size of 0.1 mm3 to 3.83 mm3. The occurring of multi air bubbles is also monitored by this capacitive sensor for distinguishing each bubble when the bubbles have a small distance among them.
Keywords: Capacitive sensor, Fluidic sensor, Air bubble detection.
References
[2] Kuo-Ting Wu, “Engine Oil Condition Monitoring Using High Temperature Integrated Ultrasonic Transducers,” Industrial Materials Institute, National Research Council Canada, Boucherville, Quebec, Canada J4B 6Y4, 2011
[3] Barak M, Katz Y (2005) Micro bubbles: pathophysiology and clinical implications. chest 128(4):2918–2932.
[4] P. Johnson, L. Karlsson, U. Forsberg, M. Gref, B. Stegmayr, “Air bubbles pass the security system of the dialysis device without alarming,” Artif. Organs 31(2):132–139, 2007.
[5] J. Zhe, A. Jagtiani, P. Dutta, J. Hu and J. Carletta, “A micromachined high throughput Coulter counter for bioparticle detection and counting,” J. Micromech. Microeng., Vol.17, pp. 304-313, 2007.
[6] J. Wei, “Silicon MEMS for detection of liquid and solid fronts,” PhD Thesis, Delft University of Technology, 2010.
[7] Vu Quoc Tuan, “Design and fabrication of a capacitive sensor based on printed circuit board
for air bubble inside fluidic flow detection,” Master thesis, University of Engineering and Technology, Vietnam National University, Hanoi, 2014.
[8] M. van der Velden, J. Wei, J.W. Spronck, R.H. Munnig Schmidt and P.M. Sarro, “Characterization of a nozzle-integrated capacitive sensor for microfluidic jet systems,” Proc. IEEE Sens. 2007 Conf., pp. 1241-1244, 2007.
[9] C.W. Heeren, F.C. Vermeulen, “Capacitance of Kelvin guard- ring capacitors with modified edge geometry,” J. Appl. Phys. 46(6):2486–2490, 1975.
[10] D. Marioli, E. Sardini, A. Taroni, “Measurement of small capacitance variations,” IEE Trans Instrum. Meas. 40(2):426–428, 1991.
[11] A. Heidary, G.C.M. Meijer, “An integrated interface circuit with a capacitance-to-voltage converter as front-end for grounded capacitive sensors,” Meas. Sci. Technol. 20:015202, 2009.
[12] T. Vu Quoc, H. Nguyen Dac, T. Pham Quoc, D. Nguyen Dinh, T. Chu Duc, “A printed circuit board capacitive sensor for air bubble inside fluidic flow detection,” Microsystem Technologies Journal, 2014.
[13] M.L. Meade, “Advances in lock-in amplifiers,” J. Phys. E: Sci. Instrum., Vol.15, pp.395-403,1982.