The Design, Optimization and Experimental Framework for Pressure Sensors
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Materials engineering (MPAEM), MSc
Publicerad
2024
Författare
Al Rawahi, Sabah
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
This thesis explores the fabrication and optimization of thin-film pressure sensors
(TFPS) using graphite (Gr) as the active material and polyvinyl alcohol (PVA)
as the binder. Three TFPS samples were fabricated and tested under both lowpressure
(below 800 Pa) and high-pressure (1 MPa to 5.5 MPa) conditions, with key
performance parameters—sensitivity, limit of detection (LOD), response time, and
stability—evaluated. Results indicated that the sensors demonstrated high sensitivity
in the high-pressure range but exhibited limited sensitivity for low-pressure range.
Sensitivity values in the low-pressure range were 6.8×10−5kPa−1±1.8×10−4kPa−1
2.1 × 10−5kPa−1±1.9 × 10−4kPa−1 and 3.4 × 10−5kPa−1±1.8 × 10−4kPa−1, while
in the high-pressure range, they were 1.9 × 10−4kPa−1±2.9 × 10−5kPa−1, 1.6 ×
10−4kPa−1±2.6 × 10−5kPa−1 and 1.5 × 10−4kPa−1±3.0 × 10−5kPa−1 for samples
1, 2, and 3, respectively. The LOD ranged from 6.6 × 10−2 kPa±2.8 × 10−2 kPa
to 5.6 × 10−2 kPa±2.9 × 10−2 kPa in the low-pressure range and 1.7 × 10−3 kPa
±8.2×10−9 kPa to 2.0×10−3 kPa ±9.5×10−9 kPa in the high-pressure range. Stability
tests suggested potential applications in health monitoring and insole pressure
sensing. However, the response time (82 ms) of the fabricated sensors is relatively
slow. Proposed improvements include the use of automated systems to reduce human
error and alternative coating methods to improve film homogeneity. As well
as, incorporating an additional component between the CCAF and the film to allow
better stress distribution within the material; since the rigidity of the film promotes
slippage between the CCAF and the film. Additional testing methods to observe the
unloading behavior of the film in respect to pressure and relative resistance could
contribute to further observations not covered. The study, however, highlights the
feasibility of using accessible, low-cost materials for TFPS fabrication, offering insights
for future sensor optimization
Beskrivning
Ämne/nyckelord
thin-film pressure sensor , force , graphite , sensitivity , limit of detection , response time , optimization , testing , active material