Strain energy shuttle apparatus and method for vibration energy harvesting
First Claim
17. An energy harvesting apparatus comprising:
- a support substrate;
a piezoelectric wafer secured to a surface of said support substrate;
a base for supporting said support substrate in a manner to enable oscillating motion of said support substrate and said piezoelectric wafer; and
a biasing element operatively associated with opposite longitudinal ends of said support substrate for supplying a mechanical compressive pre-load force to said piezoelectric wafer, sufficient to deflect said wafer into one of two flexed orientations in the absence of vibration energy, to thus soften said piezoelectric wafer to facilitate oscillating motion of said wafer in response to vibration experienced by said base.
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Accused Products
Abstract
An apparatus for use in low frequency vibration energy harvesting (VEH) and with actuators requiring a low deflection force. The apparatus includes a piezo flexure that is loaded with a compressive pre-load force to place the piezo flexure under compression. The piezo flexure may be supported at an intermediate point or at one end thereof. The compressive pre-load force produces flexes the piezo flexure into one or the other of two stable positions, these positions being offset on opposite sides of a longitudinal centerline representing the position of the piezo flexure that would be produced without the compressive pre-load force applied thereto. The compressive pre-load effectively provides a negative spring constant which “softens” the piezo flexure and enhances a responsiveness of the piezo flexure to low frequency vibration energy. The piezo flexure also operates over a much wider frequency bandwidth than conventional systems incorporating a tip mass.
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Citations
34 Claims
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17. An energy harvesting apparatus comprising:
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a support substrate;
a piezoelectric wafer secured to a surface of said support substrate;
a base for supporting said support substrate in a manner to enable oscillating motion of said support substrate and said piezoelectric wafer; and
a biasing element operatively associated with opposite longitudinal ends of said support substrate for supplying a mechanical compressive pre-load force to said piezoelectric wafer, sufficient to deflect said wafer into one of two flexed orientations in the absence of vibration energy, to thus soften said piezoelectric wafer to facilitate oscillating motion of said wafer in response to vibration experienced by said base. - View Dependent Claims (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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22-1. The apparatus of claim 17, wherein said piezoelectric wafer comprises a piezoelectric ceramic wafer.
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27. A method for vibration energy harvesting, comprising:
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disposing a piezoelectric wafer on a support substrate;
supporting said support substrate to enable oscillating motion of said support substrate;
applying a compressive stress to said support substrate that is sufficient to deflect said piezoelectric wafer from a central, non-flexed position, into one of two flexed positions, said compressive stress operating to soften said piezoelectric wafer to enhance a response of said wafer to vibration energy. - View Dependent Claims (28, 29, 30)
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31. A method for forming an actuator using a piezoelectric wafer, comprising:
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supporting the piezoelectric wafer on a support substrate to enable motion of said piezoelectric wafer; and
placing said support substrate and said piezoelectric wafer under a compressive pre-load stress sufficient to hold said piezoelectric wafer in a flexed, non-linear configuration, said compressive pre-load operating to soften said wafer and enhance a sensitivity of wafer. - View Dependent Claims (32, 33, 34)
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Specification