Dielectric composites made using P(VDF-CTFE) 88/12 mol% as polymer matrix and both micro-sized and nano-sized CaCu 3 Ti 4 O 12 (CCTO) particles as filler are developed. These composites exhibit high dielectric constant with a small dielectric loss. More importantly, it is found that the dielectric constant of these composites is almost independent of temperature from 25 ℃ to 125 ℃. Comparing the composites made using micro-sized CCTO particles, the composites made using nano-sized CCTO particles exhibit a smaller dielectric loss. The dielectric properties of these composites indicate that the nano-sized CCTO particles have a smaller dielectric constant than the micro-sized CCTO particles.

The new design of a piezoelectric diaphragm as a sensor platform is introduced. A pressure chamber is added through the packaging process. It is theoretically indicated that the sensitivity of a piezoelectric diaphragm with an introduced pressure difference between two sides is significantly higher than that without this pressure difference. The high sensitivity is also experimentally proven. The resonance behavior of the piezoelectric diaphragm was characterized for the diaphragm under different conditions. It is found that the introduction of this pressure difference improves the quality merit of the device.I.