Purdue Research Foundation

University of Notre Dame Du Lac

National Technology & Engineering Solutions of Sandia, LLC

Fabio Semperlotti

Mihir Sen

Carlo Scalo

Timothy Walsh

Hongfei Zhu

Ting-Wei Liu

Haitian Hao

Mehdi Jokar

A system includes a first structure, wherein the first structure lacks space inversion symmetry, and wherein the first structure includes a first elastic lattice. The system further includes a second structure, wherein the second structure lacks space inversion symmetry, and wherein the second structure includes a second elastic lattice. Additionally, the system includes the first structure coupled to the second structure such that the first structure and the second structure have a mirror symmetry to each other.

Phononic system and method of making the same

A method of using an acoustic resonator including receiving at a first stage of a resonator an incoming acoustic wave. The method further includes resonating the incoming wave with a flexible membrane, a taper of the flexible membrane, and a cavity of a first stage, thereby producing synergistic effect on a resulting acoustic resonance. Additionally, the method includes transforming an acoustic energy associated with the incoming acoustic wave into an elastic energy, wherein the elastic energy is channeled through the flexible membrane, thereby reducing an intensity of the incoming acoustic wave and resulting in a first reduced incoming acoustic wave. Further the method includes transferring the first reduced incoming acoustic wave through a hole of a neck of the flexible membrane. The method also includes transferring a first pressure wave caused by a perturbation in the flexible membrane into a second stage, thereby producing a second acoustic wave.

Helmholtz resonators with broadband capability

A thermoacoustic device includes a stage coupled to a bar, wherein the stage includes a first heating component on a first terminus of the stage. The stage further includes a first cooling component on a second terminus of the stage. A thermal conductivity of the stage is higher than a thermal conductivity of the bar. A heat capacity of the stage is higher than a heat capacity of the bar.

Thermoacoustic device and method of making the same

An acoustic shield for protecting a vibrational sensitive device includes a first unit cell and a second unit cell. The first unit cell includes a first locally resonant unit. The first locally resonant unit controls a first phase gradient and the first unit cell includes a first surface. The second unit cell includes a second surface proximate to the first surface. The second unit cell includes a second locally resonant unit embedded along the second interface. The second locally resonant unit controls a second phase gradient. The first phase gradient is different from the second phase gradient. The first unit cell and the second unit cell comprise a super cell. The acoustic shield is configured such that a vibrational wave from a first side of the super cell to a second side of the super cell is substantially attenuated.

Total-internal reflection elastic metasurfaces: design and application

A wearable, portable, self-contained refrigeration/cooling garment may effectively convert the energy of human movement into heat flux. The heat flux can then used to actively control the temperature of the human body or of part of it. In one example of the present disclosure, the garment is a type of footwear powered by the wearer's ambulation.

Methods and apparatus for human motion controlled wearable refrigeration

An embedded acoustic metamaterial lenses allows for ultrasonic beam-forming and high resolution identification of acoustic sources for structural health monitoring. The lenses design provides an alternative to conventional phased-array technology enabling the formation of steerable and collimated (or focused) ultrasonic beams by exploiting a single transducer. The ultrasonic beam can be steered by simply tuning the frequency of the excitation. Also, the embedded lens can be designed to achieve sub-wavelength resolution to clustered acoustic sources which is a typical scenario encountered in incipient structural damage.

Growing community of inventors

Lafayette, IN, United States of America

Fabio Semperlotti