US7166952B2 – Piezoelectric Structures – Google Patents

Diferentes causas del dolor de cabeza - Infografías de.. However, as is seen graphically in the accompanying Drawings (discussed further hereinafter), the elongate body: need not be straight, like a tape, but can be curved; need not be parallel-sided, like a tape, but can (for instance) be triangular; and need not be long and thin, like a tape, but can be disk-like (though a disk-shaped body could, for the purposes of this invention, be considered as a number of triangular “radial” segments fixed side by side round in a circle).

Dolor lumbar Consider a (planar) circular arc 81, fixed at one end 87 (as shown in FIG. 7 can then be curved into an arc to create a variant that deforms up and down across the plane of the arc. However, if the corrugations are curved in the plane of the strip, or if the strip is dished, then it bends much less easily, and so can apply a greater force when actuated. However, beams can be supported at both ends with a bending middle section.

A further important shape, alluded to above, is that of a (part) ring or annulus, as though a tape-like body were bent round in its own plane, to bring its two ends towards each other to form an object like a broken washer. In both the V- and U-shaped devices there are three distinct piezoelectric portion, two in the top group and one in the bottom group.

Dolor Neuropático Periférico

Cirurgia de Manguito Rotador - Dr. Fábio Pizzo Ribeiro Thus, the invention provides a piezoelectric device that is a simple, single-layer elongate body physically shaped in a direction across the length of the elongate body so as to have separate, distinct piezoelectric-portion groups extending along the body and on each side of a nominal median plane through the whole body, which groups are thus spatially separated by and face each other across that median plane, with the result that any piezoelectric portion dimension change in the group on one side of the median plane will tend to bend the whole device normal to the median plane and along its length in the opposite direction to the same sense piezoelectric portion dimension change in the group on the other side of that median plane.

The portions of the sheet represented by the peaks (on the top side) are thus disposed in a generally-planar group which is spatially separated from, and distinct from, yet faces the similar generally-planar group formed from the portions represented by the troughs (on the bottom side). Another variant is that wherein the corrugations are reversed halfway along the body, so that the peaks become troughs, and the troughs peaks. If, instead, all the trough portions (bottom group) were caused to contract, the body’s dimensions on its lower side would reduce, and it would bend down, towards that side-it would become concave, with that lower side on the inside. Thus, if each piezoelectric-layer portion in the group on one side of the median is expanded/lengthened then the whole will become convex with that group on the outside, while if instead each layer portion in the group on the other side is expanded/lengthened then the whole will become convex with that group on the outside.

Dolor De Hombro

The simplest such shape is probably a V-shape, with the median plane extending across the arms from the centre line of one to the centre line of the other, so that the two free tips/edges are one side and the corner angle is the other. It can be corrugated in either of two different ways-the two FIGS. As is discussed in more detail hereinafter, such a shape can be corrugated in a number of ways-the corrugations can be straight across the annulus, and thus generally radial, or they can be at some angle to the theoretical radii, and they can be either actually straight or alternatively slightly curved into arcs. Though, as discussed in more detail hereinafter, the device may have any overall shape, one preferred such shape is that of an elongate body, like a beam. After these simple shapes there is the plain corrugated sheet discussed above-this can be seen to be much like a multiplicity of Us joined side by side-and a variant on that, in which the corrugations are square rather than curved.

  • Debilidad y torpeza en la mano
  • Bajas defensas
  • Nerviosismo, insomnio y trastornos del apetito
  • Cruza los dedos
  • Molestias y dolores musculares
  • Exposición a altitud: dónde la concentración de oxígeno atmosférico disminuye

Much interest is presently being shown in the use of piezoelectric materials to construct actuators for a wide variety of mechanical devices, ranging from loudspeaker drivers to camera lens focusing systems, from electric toothbrushes to computer disk drive head positioners, and from aircraft-wing de-icers to gas valve controllers. Piezoelectric materials are poled by subjecting them to a very strong electric field, which causes the individual domains within the material to align with the field. This type of structure, novel and inventive in its own right, demonstrates a device geometry that significantly amplifies the normal relatively small deformation of piezoelectric materials to produce a large displacement. The centre line running along that section from side to side extends all the way along the sheet, and thus forms the sheet’s median plane; half of the corrugations are on one side of that plane-the top, say-and the other half are on the other side-the bottom.