Ferrofluid Sacrificial Microfabrication of Capacitive Pressure Sensors
- 24 July 2014
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Sensors Journal
- Vol. 14 (10), 3442-3447
- https://doi.org/10.1109/jsen.2014.2342716
Abstract
A novel production approach to the fabrication of capacitive micropressure sensors is reported. A magnetic fluid known as ferrofluid is used as the liquid-phase sacrificial layer in the microfabrication process, enabling extremely simple, fast, and low-cost production of the sensors while eliminating the need for photolithographic, bonding, and/or chemical processes. The entire sensor fabrication is performed at/near room temperature. The sensors are designed to be constructed on the 1.5 × 1.5-mm 2 stainless-steel chip, being micromachined to have capacitive cavities with 10-30 μm depths. A Parylene-C membrane with a titanium 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 after the formation of the membrane, suspending it to establish the sensing capacitor. A highly linear response 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.Keywords
Funding Information
- Natural Sciences and Engineering Research Council of Canada
- British Columbia Knowledge Development Fund
- Canada Research Chairs Program
- Canada Foundation for Innovation
This publication has 21 references indexed in Scilit:
- A molybdenum MEMS microhotplate for high-temperature operationSensors and Actuators A: Physical, 2012
- Non-lithographically microfabricated capacitive pressure sensor for biomedical applicationsElectronics Letters, 2011
- Development of a compensated capacitive pressure and temperature sensor using adhesive bonding and chemical-resistant coating for multiphase chemical reactorsSensors and Actuators A: Physical, 2010
- Solid on liquid depositionThin Solid Films, 2010
- Liquid-Phase Packaging of a Glucose Oxidase Solution with Parylene Direct Encapsulation and an Ultraviolet Curing Adhesive Cover for Glucose SensorsSensors, 2010
- Surface Engineering and Patterning Using Parylene for Biological ApplicationsMaterials, 2010
- Electrostatically driven micro-hydraulic actuator arraysPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2010
- Robust designed capacitive gas pressure sensor for harsh environmentPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2009
- Adhesive bonding with SU-8 in a vacuum for capacitive pressure sensorsSensors and Actuators A: Physical, 2008
- Wafer Bonding with BCB and SU-8 for MEMS PackagingPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2006