  The flexible capacitive pressure sensors are one of the most essential and
famous devices with vast applications in automobile, aerospace, marine,
healthcare, wearables, consumer, and portable electronics. The fabrication of
pressure sensors in a cleanroom is expensive and time-consuming; however, the
sensitivity, linearity, and other performance factors of those pressure sensors
are exceptional. Moreover, sometimes we require sensors that are not expensive
and can be fabricated rapidly where the other performance factors do not need
to be highly remarkable. In this modern era, household materials and DIY
(Do-it-yourself) techniques are quite helpful, highly utilized. They are
recommended to fabricate low-cost sensors and healthcare devices for
personalized medicine and low-cost consumer electronics. Different flexible
capacitive pressure sensors are presented and experimentally characterized for
acoustic and air-pressure monitoring in this thesis. The design criteria of a
cantilever-based capacitive pressure sensor are discussed. The three different
designs are analysed with aspect ratios of 1.5, 1.0, and 0.67. The sensor with
an aspect ratio of 0.67 shows maximum sensitivity (mechanical and electrical),
better response time, and the 1st and 2nd mode of resonant frequencies is
comparatively less than the other two. The cantilever designs are susceptible
to slight pressure; therefore, the diaphragm-based normal mode capacitive
pressure sensor is introduced in the second chapter, which defines the design
criteria of diaphragm shapes. The five different diaphragms analysed are
circular, elliptical, pentagon, square, and rectangular shapes. The circular
capacitive pressure sensor shows maximum sensitivity, however, maximum
non-linear response.....
