IP Library › Granted Patent US 12,626,680
Granted Patent B2
US 12,626,680 · App. 18/312,206 · Granted May 12, 2026

Systems and methods for flexural wave absorption bandpass filtering

Inventors: Xiaopeng Li (Ann Arbor, MI); Taehwa Lee (Ann Arbor, MI); Ziqi Yu (Ann Arbor, MI)
Assignees: Toyota Motor Engineering & Manufacturing North America, Inc.; Toyota Jidosha Kabushiki Kaisha
G10K11/172
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Quick Facts
Patent No.
US 12,626,680
App. No.
18/312,206
Granted
May 12, 2026
Kind
B2
Abstract

System, methods, and other embodiments described herein relate to absorbing flexural waves. In one embodiment, a system includes a longitudinally extending body that is subject to a flexural wave and a bandpass filter. The bandpass filter transmits a target flexural wave having a particular wavelength and blocks a non-target flexural wave. The bandpass filter includes at least two mechanical resonators coupled to a surface of the longitudinally extending body and aligned in a first linear array along a length dimension of the longitudinally extending body. The at least two mechanical resonators of the first linear array are separated by a distance based on the particular wavelength.

Claims (51)

1 . A system, comprising:

a longitudinally extending body that is subject to a flexural wave;

a first bandpass filter, that transmits a target flexural wave having a particular wavelength and blocks a non-target flexural wave, comprising at least two mechanical resonators coupled to a surface of the longitudinally extending body and aligned in a first linear array along a length dimension of the longitudinally extending body, the at least two mechanical resonators being separated by a distance based on the particular wavelength and physical properties of the at least two mechanical resonators; and

a second bandpass filter comprising at least two additional mechanical resonators, the second bandpass filter is decoupled from the first bandpass filter.

2 . The system of claim 1 , wherein the at least two mechanical resonators are separated by a distance that is greater than 0.45λ, where λ is the particular wavelength.

3 . The system of claim 1 , wherein the second bandpass filter comprising at least two additional mechanical resonators is aligned in a second linear array along the length dimension of the longitudinally extending body, the second bandpass filter:

is parallel to the first bandpass filter along the length dimension of the longitudinally extending body;

is asymmetrical to the first bandpass filter; and

targets a second target flexural wave with a different wavelength than the target flexural wave.

4 . The system of claim 1 , wherein each mechanical resonator comprises a channel in the surface of the longitudinally extending body.

5 . The system of claim 1 , wherein each mechanical resonator comprises:

a rigid mass component; and

a connecting element connected to the rigid mass component, the connecting element maintains the rigid mass component at an elevated distance from the longitudinally extending body.

6 . The system of claim 5 , wherein the connecting element comprises one of:

a spring;

a soft base component; and

a rigid base component and an arm extending at an angle from the rigid base component.

7 . The system of claim 6 , wherein:

arms of the at least two mechanical resonators extend in a same direction along the length dimension of the longitudinally extending body.

8 . The system of claim 6 , wherein:

arms of the at least two mechanical resonators extend in opposite directions along the length dimension of the longitudinally extending body; and

the rigid mass components of the at least two mechanical resonators are adjacent one another.

9 . The system of claim 6 , wherein:

arms of the at least two mechanical resonators extend in opposite directions along the length dimension of the longitudinally extending body; and

the rigid mass components of the at least two mechanical resonators are separated from one another by respective arms.

10 . A system, comprising:

a longitudinally extending body that is subject to a flexural wave;

a first bandpass filter, that transmits a target flexural wave having a particular wavelength and blocks a non-target flexural wave, comprising at least two mechanical resonators coupled to a surface of the longitudinally extending body and aligned in a linear array along a length dimension of the longitudinally extending body, the at least two mechanical resonators being separated by a distance:

based on physical properties of the at least two mechanical resonators;

that is greater than 0.45λ, where λ is the particular wavelength; and

a second bandpass filter comprising at least two additional mechanical resonators, the second bandpass filter is decoupled from the first bandpass filter.

11 . The system of claim 10 , wherein the second bandpass filter comprising at least two additional mechanical resonators is aligned in a second linear array along the length dimension of the longitudinally extending body, the second bandpass filter:

is parallel to the first bandpass filter along the length dimension of the longitudinally extending body;

is asymmetrical to the first bandpass filter; and

targets a second target flexural wave with a different wavelength than the target flexural wave.

12 . The system of claim 10 , wherein each mechanical resonator comprises a channel in the surface of the longitudinally extending body.

13 . The system of claim 10 , wherein each mechanical resonator comprises:

a rigid mass component; and

a connecting element connected to the rigid mass component, the connecting element maintains the rigid mass component at an elevated distance from the longitudinally extending body.

14 . The system of claim 13 , wherein the connecting element comprises one of:

a spring;

a soft base component; and

a rigid base component and an arm extending at an angle from the rigid base component.

15 . The system of claim 14 , wherein:

arms of the at least two mechanical resonators extend in a same direction along the length dimension of the longitudinally extending body.

16 . The system of claim 14 , wherein:

arms of the at least two mechanical resonators extend in opposite directions along the length dimension of the longitudinally extending body; and

the rigid mass components of the at least two mechanical resonators are adjacent to one another.

17 . The system of claim 14 , wherein:

arms of the at least two mechanical resonators extend in opposite directions along the length dimension of the longitudinally extending body; and

the rigid mass components of the at least two mechanical resonators are separated from one another by respective arms.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 17, 2026
From: TOYOTA MOTOR ENGINEERING & MANUFACTURING NORTH AMERICA, INC.
To: TOYOTA JIDOSHA KABUSHIKI KAISHA
Reel/Frame 074994/0856 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 12, 2023
From: LI, XIAOPENG; LEE, TAEHWA; YU, ZIQI
To: TOYOTA MOTOR ENGINEERING & MANUFACTURING NORTH AMERICA, INC.; TOYOTA JIDOSHA KABUSHIKI KAISHA
Reel/Frame 063627/0751 →
Continuity (1)
Related Publication 20240371349A1 · Nov 7, 2024
References Cited (100)
US 4137511A · Jones · 1979 [cited by examiner]
US 4373608A · Holmes · 1983 [cited by examiner]
US 4492246A · Prescott et al. · 1985 [cited by applicant]
US 5499526A · Muro · 1996 [cited by applicant]
US 6134964A · Jaenker et al. · 2000 [cited by applicant]
US 7312674B2 · Duwel · 2007 [cited by examiner]
US 7358503B2 · Fellerman et al. · 2008 [cited by applicant]
US 7551058B1 · Johnson et al. · 2009 [cited by applicant]
US 8960365B2 · Sheng · 2015 [cited by examiner]
US 9411029B2 · Pirkl · 2016 [cited by applicant]
US 9466283B2 · Yang · 2016 [cited by examiner]
US 9933503B2 · Vernickel et al. · 2018 [cited by applicant]
US 10284176B1 · Solal · 2019 [cited by applicant]
US 10717672B2 · Loh et al. · 2020 [cited by applicant]
US 10724994B2 · Van Tooren et al. · 2020 [cited by applicant]
US 11022561B2 · Ziehl · 2021 [cited by applicant]
US 11158299B2 · Chunren · 2021 [cited by examiner]
US 11339545B2 · Hsu · 2022 [cited by examiner]
US 11524637B2 · Chang · 2022 [cited by examiner]
US 11688379B2 · Lee · 2023 [cited by examiner]
US 20150338380A1 · Ziehl et al. · 2015 [cited by applicant]
US 20170115382A1 · Koudar et al. · 2017 [cited by applicant]
US 20180107015A1 · Dümpelmann et al. · 2018 [cited by applicant]
US 20220051650A1 · Lee et al. · 2022 [cited by applicant]
US 20220190231A1 · Li et al. · 2022 [cited by applicant]
US 20220214312A1 · Lee · 2022 [cited by examiner]
US 20220285604A1 · Li et al. · 2022 [cited by applicant]
DE 4336112A1 · 1995 [cited by applicant]
Wu et al., “Asymmetric scattering of flexural waves in a parity-time symmetric metamaterial beam,” The Journal of the Acoustical Society of America, vol. 146, 2019, pp. 850-862. [cited by applicant]
Schipf et al., “Tunable piezoelectric metamaterial for Lamb waves using periodic shunted circuits,” arXiv:2207.07845v1, Jul. 16, 2022, pp. 1-30. [cited by applicant]
Zhao et al., “Numerical analysis of effective refractive index ultrasonic sensor based on Cantilever arm structure slot-pased dual-micro-ring resonator,” International Journal of Modern Physics B, vol. 35, No. 4, 2021, … [cited by applicant]
Durdaut et al., “Phase Sensitivity and Phase Noise of Cantilever-Type Magnetoelastic Sensors Based on the ΔE Effect,” arXiv:2003.01085v1, Mar. 2, 2020, pp. 1-15. [cited by applicant]
Casadei et al., “Piezoelectric resonator arrays for tunable acoustic waveguides and metamaterials,” Journal of Applied Physics, vol. 112, 2012, pp. 1-6. [cited by applicant]
Casadei et al., “Broadband vibration control through periodic arrays of resonant shunts: experimental investigation on plates,” Smart Materials and Structures, vol. 19, No. 1, 2010, pp. 1-13. [cited by applicant]
Cardella et al., “Manipulating waves by distilling frequencies: a tunable shunt-enabled rainbow trap,” Smart Materials and Structures, vol. 25, 2016, pp. 1-15. [cited by applicant]
Jain et al., “Emerging Ideas in Nanocantilever based Biological Sensors,” arXiv:1305.5729, 2013, pp. 1-17. [cited by applicant]
Airoldi et al., “Design of tunable acoustic metamaterials through periodic arrays of resonant shunted piezos,” New Journal of Physics, vol. 13, Nov. 2011, pp. 1-21. [cited by applicant]
Chen et al., “Exceptional points enhance sensing in an optical microcavity,” Nature, vol. 548, 2017, pp. 192-196. [cited by applicant]
Su et al., “Research on damage visualization of concrete structures based on electrical resistance tomography,” Frontiers in Physics, 2022, pp. 1-12. [cited by applicant]
Ashida et al., “Non-Hermitian physics,” Advances in Physics 69 (3) (2020), pp. 249-435. [cited by applicant]
Guo et al., “Observation of PT-symmetry breaking in complex optical potentials,” Physical review letters, vol. 103, Iss. 9, 2009, 4 pages. [cited by applicant]
Lee et al., “Topolectrical circuits,” Communications Physics 1 (1), 2018, pp. 1-9. [cited by applicant]
Yoshida et al., “Exceptional rings protected by emergent symmetry for mechanical systems,” Physical Review B, vol. 100, Iss. 5, 2019, pp. 1-17. [cited by applicant]
Fleury et al., “An invisible acoustic sensor based on parity-time symmetry,” Nature communications 6 (1), 2015, pp. 1-7. [cited by applicant]
Zangeneh-Nejad et al., “Active times for acoustic metamaterials,” Reviews in Physics, vol. 4, Nov. 2019, pp. 1-17. [cited by applicant]
Ding et al., “Emergence, coalescence, and topological properties of multiple exceptional points and their experimental realization,” Physical Review X, vol. 6, Iss. 2, 2016, 13 pages. [cited by applicant]
Gear et al., “Unidirectional zero reflection as gauged parity-time symmetry,” New Journal of Physics, vol. 19, Iss. 12, 2017, pp. 1-10. [cited by applicant]
Lin et al., “Unidirectional invisibility induced by PT-symmetric periodic structures,” Physical Review Letters, vol. 106, Iss. 21, 2011, pp. 1-4. [cited by applicant]
Li et al., “Experimental demonstration of extremely asymmetric flexural wave absorption at the exceptional point,” Extreme Mechanics Letters, vol. 52, Apr. 2022, pp. [cited by applicant]
Wang et al., “Extremely asymmetrical acoustic metasurface mirror at the exceptional point,” Physical review letters, vol. 123, Iss. 21, Nov. 2019, pp. 1-5. [cited by applicant]
Hodaei et al., “Enhanced sensitivity at higher-order exceptional points,” Nature, vol. 548 (7666), Aug. 2017, pp. 187-191. [cited by applicant]
Assawaworrarit et al., “Robust wireless power transfer using a nonlinear parity-time-symmetric circuit,” Nature, vol. 546 (7658), Jun. 2017, pp. 387-390. [cited by applicant]
Peng et al., “Parity-time-symmetric whispering-gallery microcavities,” Nature Physics, vol. 10, Iss. 5, May 2014, pp. 394-398. [cited by applicant]
Yi et al., “Asymmetric viscoelastic metamaterials for broad bandgap design and unidirectional zero reflection,” Mechanical Systems and Signal Processing, vol. 162, Jan. 2022, pp. [cited by applicant]
Wang et al., “Coherent perfect absorption at an exceptional point,” Science, vol. 373, Iss. 6560, Sep. 2021, pp. 1261-1265. [cited by applicant]
Sweeney et al., “Perfectly absorbing exceptional points and chiral absorbers,” Physical review letters, vol. 122, Iss. 9, Mar. 2019, pp. 1-6. [cited by applicant]
Zhu et al., “Simultaneous observation of a topological edge state and exceptional point in an open and non-Hermitian acoustic system,” Physical review letters, vol. 121, Iss. 12, Sep. 2018, pp. 1-14. [cited by applicant]
Liu et al., Willis metamaterial on a structured beam, Physical Review X, vol. 9, Iss. 1, 2019, pp. 1-21. [cited by applicant]
Domínguez-Rocha et al., “Environmentally induced exceptional points in elastodynamics,” Physical Review Applied 13 (1), 2020, pp. 1-8. [cited by applicant]
Cummer et al., “Controlling sound with acoustic metamaterials,” Nature Reviews Materials, vol. 1, Iss. 3, Mar. 2016, pp. 1-13. [cited by applicant]
Chen et al., “A review of tunable acoustic metamaterials,” Applied Sciences, vol. 8, Iss. 9, 2018, pp. 1-21. [cited by applicant]
Ji et al., “Recent progress in acoustic metamaterials and active piezoelectric acoustic metamaterials—a review,” Applied Materials Today, vol. 26, Mar. 2022, pp. 1-28. [cited by applicant]
Popa et al., “Non-reciprocal and highly nonlinear active acoustic metamaterials,” Nature communications, vol. 5, Iss. 1, 2014, pp. 1-5. [cited by applicant]
Popa et al., “Active acoustic metamaterials reconfigurable in real time,” Physical Review B, vol. 91, Iss. 22, 2015, pp. 1-7. [cited by applicant]
Akl et al., “Analysis and experimental demonstration of an active acoustic metamaterial cell,” Journal of Applied Physics, vol. 111, Iss. 4, 2012, pp. [cited by applicant]
Chen et al., “An active mechanical willis meta-layer with asymmetric polarizabilities,” Nature communications, vol. 11 Iss. 1, 2020, pp. 1-8. [cited by applicant]
Li et al., “Shaping elastic wave mode conversion with a piezoelectric-based programmable meta-boundary,” Extreme Mechanics Letters, vol. 39, Sep. 2020, pp. 1-18. [cited by applicant]
Li et al., “An active meta-layer for optimal flexural wave absorption and cloaking,” Mechanical Systems and Signal Processing, vol. 149, Feb. 2021, pp. 1-35. [cited by applicant]
Chen et al., “Realization of active metamaterials with odd micropolar elasticity,” Nature communications, vol. 12, Iss. 1, 2021, pp. 1-12. [cited by applicant]
Li et al., “Acoustic metamaterials capable of both sound insulation and energy harvesting,” Smart Materials and Structures, vol. 25, No. 4, 2016, pp. 1-5. [cited by applicant]
Airoldi et al., “Design of tunable acoustic metamaterials through periodic arrays of resonant shunted piezos,” New Journal of Physics, vol. 13, Iss. 11, Nov. 2011, pp. 1-21. [cited by applicant]
Thomes et al., “Space-time wave localization in electromechanical metamaterial beams with programmable defects,” Mechanical Systems and Signal Processing, vol. 167, Part B, Mar. 2022, pp. 1-16. [cited by applicant]
Trainiti et al., “Time-periodic stiffness modulation in elastic metamaterials for selective wave filtering: theory and experiment,” Physical review letters, vol. 122, Iss. 12, Mar. 2019, 17 pages. [cited by applicant]
Chen et al., “Enhanced flexural wave sensing by adaptive gradient-index metamaterials,” Scientific reports, vol. 6, Iss. 1, 2016, pp. 1-11. [cited by applicant]
Zhu et al., “Experimental study of an adaptive elastic metamaterial controlled by electric circuits,” Applied Physics etters, vol. 108, Iss. 1, 2016, 6 pages. [cited by applicant]
Hu et al., “Metamaterial beam with graded local resonators for broadband vibration suppression,” Mechanical Systems and Signal Processing, vol. 146, Jan. 2021, pp. [cited by applicant]
Yi et al., “Programmable metamaterials with digital synthetic impedance circuits for vibration control,” Smart Materials and Structures, vol. 29, No. 3, 2020, pp. 1-21. [cited by applicant]
Sugino et al., “Digitally programmable resonant elastic metamaterials,” Physical Review Applied, vol. 13, Iss. 6, 2020, pp. [cited by applicant]
Wang et al., “Multi-resonant piezoelectric shunting induced by digital controllers for subwavelength elastic wave attenuation in smart metamaterial,” Smart Materials and Structures, vol. 26, No. 2, 2017, pp. 1-20. [cited by applicant]
Li et al., “A self-adaptive metamaterial beam with digitally controlled resonators for subwavelength broadband flexural wave attenuation,” Smart Materials and Structures, vol. 27, No. 4, 2018, pp. 1-13. [cited by applicant]
Gripp et al., “Vibration and noise control using shunted piezoelectric transducers: A review,” Mechanical Systems and Signal Processing, vol. 112, Nov. 2018, pp. 359-383. [cited by applicant]
Chen et al., “Elastic-electro-mechanical modeling and analysis of piezoelectric metamaterial plate with a self powered synchronized charge extraction circuit for vibration energy harvesting,” Mechanical Systems and Sign… [cited by applicant]
Nassar et al., “Nonreciprocity in acoustic and elastic materials,” Nature Reviews Materials, vol. 5, Iss. 9, 2020, pp. 667-685. [cited by applicant]
Sugino et al., “Nonreciprocal piezoelectric metamaterial framework and circuit strategies,” Physical Review B 102 (1), 2020, 7 pages. [cited by applicant]
Wu et al., “Asymmetric scattering of flexural waves in a parity-time symmetric metamaterial beam,” The Journal of the Acoustical Society of America, vol. 146, Iss. 1, 2019, pp. 850-862. [cited by applicant]
Doppler et al., “Dynamically encircling an exceptional points in a waveguide: asymmetric mode switching from the breakdown of adiabaticity,” Nature, vol. 537, 2016, pp. 76-79. [cited by applicant]
Zhang et al., “Dynamically encircling exceptional points: in situ control of encircling loops and the role of the starting point,” Physical Review X, vol. 8, Iss. 2, Apr. 2018, pp. 1-18. [cited by applicant]
A. Preumont et al., “Vibration control of active structures: an introduction,” 3rd edition, vol. 246, Springer, 2018, 202 pages. [cited by applicant]
Tang et al., “Active-passive hybrid piezoelectric networks for vibration control: comparisons and improvement,” Smart Materials and Structures, vol. 10, No. 4, 2001, pp. 794-806. [cited by applicant]
Neubauer et al., “Vibration damping with shunted piezoceramics: fundamentals and technical applications,” Mechanical Systems and Signal Processing, vol. 36, Iss. 1, 2013, pp. 36-52. [cited by applicant]
Haus et al., “Waves and fields in optoelectronics,” Prentice-Hall, Inc., Englewood Cliffs, NJ, 1984, 402, pp. [cited by applicant]
Fan et al., “Temporal coupled-mode theory for the Fano resonance in optical resonators,” JOSA A, vol. 20, Iss. 3, 2003, pp. 569-572. [cited by applicant]
Zhang et al., “A metamaterial beam with inverse nonlinearity for broadband micro-vibration attenuation,” Mechanical Systems and Signal Processing, vol. 159, Oct. 2021, pp. 1-13. [cited by applicant]
Allik et al., “Finite element method for piezoelectric vibration,” International journal for numerical methods in engineering, vol. 2, Iss. 2, 1970, pp. 151-157. [cited by applicant]
Li et al. “Observation of an exceptional point with an LR-shunted resonator.” Mechanical Systems and Signal Processing 196 (2023): 110297. [cited by applicant]
Li et al. “Experimental study of a tunable perfect flexural wave absorber with a piezoelectric shunted resonator.” Frontiers in Physics 10 (2022): 1306. [cited by applicant]
Leng et al. “Limits of flexural wave absorption by open lossy resonators: reflection and transmission problems.” New Journal of Physics 21.5 (2019): 053003. [cited by applicant]
Hisu et al. “Bound states in the continuum.” Nature Reviews Materials 1.9 (2016): 1-13. [cited by applicant]
U.S. Appl. No. 18/133,135, filed Apr. 11, 2023. [cited by applicant]
U.S. Appl. No. 18/133,076, filed Apr. 11, 2023. [cited by applicant]