TY - GEN
T1 - Microfabrication of capacitive pressure sensors using ferrofluid sacrificial layers
AU - Assadsangabi, Babak
AU - Chen, Xing
AU - Brox, Dan
AU - Takahata, Kenichi
PY - 2013/1/1
Y1 - 2013/1/1
N2 - A novel micromachined capacitive pressure sensor that is fabricated using a liquid-phase sacrificial layer is reported. Ferrofluid serves as the sacrificial layer in the microfabrication process, enabling extremely simple, fast, and low-cost production of the sensor, while eliminating the need for photolithographic, bonding, and/or chemical processes. The entire sensor fabrication is performed at/near room temperature. The sensor is based on the 1.5×1.5-mm2 stainless-steel chip with a 10-μm-deep capacitive cavity. A Parylene-C membrane with a Ti electrode is formed to seal the cavity by depositing it directly on top of the ferrofluid filled in the cavity. The ferrofluid is magnetically extracted from the cavity, suspending the membrane to form the sensing capacitor. A highly linear response with a sensitivity of 12.4 fF/KPa is obtained with the fabricated device. The temperature dependence of the sensor capacitance is experimentally characterized and reported as well.
AB - A novel micromachined capacitive pressure sensor that is fabricated using a liquid-phase sacrificial layer is reported. Ferrofluid serves as the sacrificial layer in the microfabrication process, enabling extremely simple, fast, and low-cost production of the sensor, while eliminating the need for photolithographic, bonding, and/or chemical processes. The entire sensor fabrication is performed at/near room temperature. The sensor is based on the 1.5×1.5-mm2 stainless-steel chip with a 10-μm-deep capacitive cavity. A Parylene-C membrane with a Ti electrode is formed to seal the cavity by depositing it directly on top of the ferrofluid filled in the cavity. The ferrofluid is magnetically extracted from the cavity, suspending the membrane to form the sensing capacitor. A highly linear response with a sensitivity of 12.4 fF/KPa is obtained with the fabricated device. The temperature dependence of the sensor capacitance is experimentally characterized and reported as well.
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U2 - 10.1109/ICSENS.2013.6688301
DO - 10.1109/ICSENS.2013.6688301
M3 - Conference contribution
AN - SCOPUS:84893922307
SN - 9781467346405
T3 - Proceedings of IEEE Sensors
BT - IEEE SENSORS 2013 - Proceedings
PB - IEEE Computer Society
T2 - 12th IEEE SENSORS 2013 Conference
Y2 - 4 November 2013 through 6 November 2013
ER -