초록 ▼

Laminates of polyvinylidene fluroride (PVDF) are employed as piezoelectric sensors and actuators which can sense and/or generate complex motions that include bending, stretching, and twisting components. The laminates can be attached directly to a mechanical structure whose motions are to be sensed

Laminates of polyvinylidene fluroride (PVDF) are employed as piezoelectric sensors and actuators which can sense and/or generate complex motions that include bending, stretching, and twisting components. The laminates can be attached directly to a mechanical structure whose motions are to be sensed and/or controlled. By skewing the principal axes of each of the lamina in the laminate with respect to one another, the laminate is responsive not only to bending motions, but to torsional motions as well. Surface electrodes are disposed on the top and bottom sides of each of the lamina to either sense voltage generated by the lamina in response to motion imparted thereto, or supply voltage to the lamina to induce motion therein. The shape of the surface electrode patterns can be varied to control the particular components of motion to which each of the lamina is responsive (e.g., bending modes). The polarization profile in each of the lamina can also be varied for this purpose. Mechanical oscillators and dampers can be constructed using the laminates.

대표청구항 ▼

Apparatus for sensing and controlling complex motions in a mechanical structure comprising: an integrated distributed piezoelectric sensor/actuator for attachment to a mechanical structure including: a laminate comprising at least four stacked laminae of piezoelectric material; each of said lamina h

Apparatus for sensing and controlling complex motions in a mechanical structure comprising: an integrated distributed piezoelectric sensor/actuator for attachment to a mechanical structure including: a laminate comprising at least four stacked laminae of piezoelectric material; each of said lamina having top and bottom sides, a thickness, and a principal axis defining the direction along which the top side of the lamina will contract or expand relative to the bottom side of the lamina upon application of an electrical signal across the thickness of the lamina, and conversely defining the direction along which when the lamina is contracted or expanded, an electrical signal will be generated across the thickness thereof; wherein a first pair of said at least four laminae have their principal axes skewed with respect to one another and include means to sense electrical signals generated across the thicknesses thereof in response to stress or strain applied thereto; and, a second pair of said at least four laminae have their principal axes skewed with respect to one another and include means to supply electrical signals across the thicknesses thereof to impart bending motions to the second pair of laminae; whereby, when the laminate is attached to a mechanical structure, both bending and torsional motions of the structure can be determined without signal processing from signals generated by the first pair of laminae, and bending and torsional motions can be generated in the mechanical structure by supplying electrical signals to the second pair of laminae.