| 摘要 |
<p>PROBLEM TO BE SOLVED: To enhance the sensitivity of a pressure sensor by employing a copolymer film of vinylidene fluoride of specified concentration having a modulus of tensile elasticity in the direction of film face equal to or lower than a specified value and trifluoroethylene. SOLUTION: The piezoelectric element 2 comprises a copolymer film of 70-83mol% of vinylidene fluoride and trifluoroethylene and/or tetrafluoroethylene. The piezoelectric element 2 has a modulus of tensile elasticity in the direction of film face equal to or lower than 2.9×10<9> N/m<2> and it is polarized in the thickness direction of the film. In a pressure sensor employing such a macromolecular piezoelectric, the piezoelectric element 2 is deformed by pressure difference when two gases having different pressure are introduced through respective pressure introduction ports 3 to the piezoelectric element 2 in a pressure chamber, and the polarization amount is varied. Consequently, charges are generated on the opposite sides of the piezoelectric and outputted in the form of a voltage, for example, through an electrode layer and holders 1, 4. A micro pressure as low as 10mPa can be detected with this pressure sensor.</p> |
