Broadband electromechanical spectroscopy

Patent metadata

Field	Value
Publication number	US-9291536-B2
Application number	US-201414246731-A
Country	US
Kind code	B2
Filing date	Apr 7, 2014
Priority date	Apr 5, 2013
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

An apparatus, method, and material wherein the material's viscoelastic and/or fatigue life may be altered by application of a secondary tuning electromagnetic field or a selected temperature, and the material's viscoelastic and/or fatigue properties are measured by a mechanical response of the material caused by applying a primary driving electromagnetic field.

First claim

What is claimed is:

1. An apparatus, comprising:
an electronic circuit for applying one or more secondary tuning electromagnetic fields to a specimen comprising a material, wherein one or more properties of the material are altered by the one or more secondary tuning electromagnetic fields;
one or more electromagnetic coils for generating one or more primary driving electromagnetic fields that produce one or more mechanical responses of the specimen comprised of the material during application of the one or more secondary tuning electromagnetic fields, or a selected temperature, or the selected temperature and the one or more secondary tuning electromagnetic fields;
a specimen grip for physically holding the specimen inside the apparatus, wherein the specimen grip electrically isolates the specimen from the apparatus while applying the one or more secondary tuning electromagnetic fields;
a clamp for attaching a permanent magnet to the specimen, wherein;
the permanent magnet converts the applied one or more primary driving electromagnetic fields to one or more mechanical forces on the specimen,
the one or more mechanical forces cause the one or more mechanical responses of the material in the specimen, and
the clamp is electrically isolated from the specimen;

a detector positioned to receive a laser beam reflected from a mirror attached to the specimen to detect one or more specimen motions,
a laser positioned to focus the laser beam on the mirror; and
a vacuum chamber enclosing at least the material to enable measurement of the one or more mechanical responses under ambient pressures from atmospheric pressure (1000 mbar) down to a vacuum pressure; and
wherein the one or more specimen motions result from the one or more mechanical responses and are used to measure the one or more properties of the material during application of the one or more secondary tuning electromagnetic fields, or the selected temperature, or the one or more secondary tuning electromagnetic fields and the selected temperature.

2. The apparatus of claim 1 , wherein the vacuum chamber enables measurement of the one or more mechanical responses under ambient pressures from atmospheric pressure (1000 mbar) down to 2*10 −6 mbar.

3. The apparatus of claim 2 , wherein the vacuum chamber is opened and closed via vertical rails allowing for up-and-down-sliding for installation of the specimen.

4. The apparatus of claim 2 , further comprising radiant heater elements placed inside the vacuum chamber such that the specimen placed inside the vacuum chamber receives radiant energy from the radiant heater elements and the radiant heater elements control the selected temperature of the specimen up to 350° C. and without airflow.

5. The apparatus of claim 4 , wherein the selected temperature induces a structural transition in the material that alters one or more of the properties.

6. The apparatus of claim 1 , further comprising a plurality of the coils of different spatial orientations to induce the one or more (simultaneous) primary driving electromagnetic fields that allow for multiaxial mechanical testing of the specimen.

7. The apparatus of claim 1 , wherein the one or more secondary tuning electromagnetic fields induce a structural transition in the material that alters one or more of the properties.

8. The apparatus of claim 1 , wherein the material comprises a ferroelectric material.

9. The apparatus of claim 1 , wherein the material comprises a ferroelectric material having the one or more properties that are tuned by application of the one or more secondary tuning electromagnetic fields, or the selected temperature, or the one or more secondary tuning electromagnetic fields and the selected temperature.

10. The apparatus of claim 1 , for performing Broadband Electromechanical Spectroscopy of the specimen, further comprising;
a waveform generator for passing current through the one or more electromagnetic coils such that one or more electromechanical responses of the specimen are measured as a function of one or more mechanical frequencies in a range of 0.01 Hz to 1 MHz and as a function of the one or more primary driving electromagnetic fields comprising one or more electric fields, wherein the one or more electric fields applied to the specimen can be one or more wave-forms having a frequency in a range of 1 mHz to at least 10 Hz.

11. The apparatus of claim 1 , wherein the electromagnetic fields are selected to measure the one or more viscoelastic properties chosen from dynamic Young modulus, shear modulus, damping capacity, creep response, relaxation response, mechanical long-term stability including fatigue, one or more electromechanically-coupled properties, and electrical fatigue.

12. The apparatus of claim 1 , wherein the electromagnetic fields are selected to measure the one or more properties of the material including one or more electromechanically-coupled properties, or an electrical fatigue property, or the one or more electromechanically-coupled properties and the electrical fatigue property.

13. The apparatus of claim 1 , wherein a structure of the material is such that the one or more secondary tuning electromagnetic fields change the materials's stiffness by 50% or more and increase the material's damping by 500% or more, as compared to without application of the one or more secondary tuning electromagnetic fields.

14. The apparatus of claim 1 , wherein the one or more properties include one or more viscoelastic properties.

15. the apparatus of claim 1 , wherein the one or more properties include a stiffness.

16. The apparatus of claim 1 , wherein the one or more properties include a damping.

17. The apparatus of claim 1 , wherein the one or more properties include a fatigue life.

18. A method for testing a material, comprising:
using an electronic circuit to apply one or more secondary tuning electromagnetic fields to a specimen comprising a material, wherein:
the one or more secondary tuning electromagnetic fields, or a selected temperature, or a selected temperature and the one or more secondary tuning electromagnetic fields, alter one or more properties of the material including one or more viscoelastic properties, or fatigue life, or the fatigue life and the one or more viscoelastic properties, and
the one or more properties are measured when the electronic circuit applies the one or more secondary tuning electromagnetic fields comprising one or more electric fields having a magnitude of up to 5 MV/m, and
a detector measures one or more motions of the specimen corresponding to one or more strain, induced in the specimen by one or more primary driving electromagnetic fields, of 10 −3 or less.

19. the method of claim 18 , further comprising:
performing Broadband electromechanical Spectroscopy of the specimen, comprising measuring one or more electromechanical responses of the specimen as a function of one or more mechanical frequencies in a range of 0.01 Hz to 1 MHz and as a function of the one or more electric fields, wherein the one or more electric applied to the specimen can be one or more wave-forms having a frequency in a range of 1 mHz to at least 10 Hz.

20. A method for testing a material, comprising:
using one or more electronic circuits to apply one or more secondary electromagnetic fields, or a selected temperature, or the one or more secondary electromagnetic fields and a selected temperature, to a material to change one or more properties of the material, the one or more properties including a viscoelastic pr

Assignees

• California Inst Of Techn

Inventors

• Kochmann Dennis M
• Wojnar Charles S
• Le Graverend Jean-Briac

Classifications

• G01N3/02 Primary

  Details · CPC title

• G01N3/068

  with optical indicating or recording means · CPC title

• G01N2203/0094

  Visco-elasticity · CPC title

• G01N2203/0073

  Fatigue · CPC title

• H01F1/01

  of inorganic materials (H01F1/44 takes precedence) · CPC title