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US 11,658,638 B2Granted
Magnetoelastic resonator and method of manufacturing same
AssigneeThe Regents of the University of Michigan
InventorsScott R. Green, Yogesh Gianchandani, Ramprasad M. Nambisan, Jiqing Jiang
Life of this patent
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Abstract
A resonator comprising a magnetoelastic body having a mass load portion and an active resonating portion can be used in implementations such as a security tag. The resonator includes a mass at the mass load portion of the magnetoelastic body. Displacement of the magnetoelastic body is configured to occur at both the mass load portion and the active resonating portion. A strain at the active resonating portion during displacement is configured to be greater than a strain at the mass load portion during displacement.
Claims19
A resonator, comprising:
- a magnetoelastic body having a mass load portion and an active resonating portion;
- and
- a mass at the mass load portion of the magnetoelastic body,
- wherein displacement of the magnetoelastic body is configured to occur at both the mass load portion and the active resonating portion, and
- wherein a strain at the active resonating portion during displacement is configured to be greater than a strain at the mass load portion during displacement, wherein a size of the mass is correlated with a size of the magnetoelastic body, wherein the size of the mass is at least partially dependent on a mass add ratio, the mass add ratio being equal to Madd/M0, wherein
- Madd=4*tm*Lm*w*ρ
- wherein,
- M0=tb*Lb*w*ρ
- and wherein tm is a thickness of the mass, Lm is a length of the mass, w is a width of the mass, ρ is a density of the magnetoelastic body, tb is a thickness of the magnetoelastic body, and Lb is a length of the magnetoelastic body.
6 more elements
A resonator, comprising:
- a magnetoelastic body having a mass load portion and an active resonating portion;
- and
- a mass at the mass load portion of the magnetoelastic body,
- wherein displacement of the magnetoelastic body is configured to occur at both the mass load portion and the active resonating portion, and
- wherein a strain at the active resonating portion during displacement is configured to be greater than a strain at the mass load portion during displacement, wherein the mass is a separate mass element coupled to the magnetoelastic body at the mass load portion, and further comprising a second separate mass element in addition to the first separate mass element, wherein the first separate mass element is coupled to a first end of the magnetoelastic body and the second separate mass element is coupled to a second end of the magnetoelastic body, with the active resonating portion located between the first separate mass element and the second separate mass element, wherein a third separate mass element is coupled to the first end of the magnetoelastic body, on an opposite side of the magnetoelastic body as the first separate mass element, and wherein a fourth separate mass element is coupled to the second end of the magnetoelastic body, on the opposite side of the magnetoelastic body as the second separate mass element.
2 more elements
A security tag, comprising:
- a housing;
- and
- a resonator, the resonator comprising:
- a magnetoelastic body having a mass load portion and an active resonating portion;
- and
- a mass at the mass load portion of the magnetoelastic body,
- wherein displacement of the magnetoelastic body is configured to occur at both the mass load portion and the active resonating portion, and
- wherein a strain at the active resonating portion during displacement is configured to be greater than a strain at the mass load portion during displacement,
- the resonator being located in the housing, wherein the resonator is not anchored to the housing.
6 more elements
A method of manufacturing a resonator, comprising the steps of:
- correlating a size of a mass with a size of a magnetoelastic body, wherein the size of the mass is at least partially dependent on a miniaturization factor of the magnetoelastic body, wherein the miniaturization factor is a length of an unloaded magnetoelastic body configured to have an unloaded resonant frequency divided by a length of the magnetoelastic body configured to have a loaded resonant frequency that is within 1 kHz of the unloaded resonant frequency;
- and
- coupling the mass to the magnetoelastic body at a mass load portion of the magnetoelastic body.
Dependencies are inferred from the claim text.