A bulk acoustic wave (BAW) resonator includes a solidly mounted reflector, for example, a Bragg-type reflector, a piezoelectric layer, and first and second electrodes on first and second surfaces, respectively, of the piezoelectric layer. A filter device or filter system includes at least one BAW resonator. Related methods of fabrication include forming the BAW resonator.

A material deposition method comprising: preparing a precursor solution of Pb(Zr.sub.x,Ti.sub.1-x)O.sub.3 using 1-methoxy-2-propanol as a solvent and acetylacetone as a modifier; and forming a seed layer for a electroactive film by spin coating the precursor solution on a substrate. The electroactive film can be PZT, PZO or BFO, spin-coated or inkjet printed on the seed layer. Experience shows pure orientation for the piezoelectric film thanks to the use of 1-methoxy-2-propanol when preparing the seed layer. This orientation is attributed to the formation of nano crystals on the seed layer constituting a pre-crystallization.

A material deposition method comprising: preparing a precursor solution of Pb(Zr.sub.x,Ti.sub.1-x)O.sub.3 using 1-methoxy-2-propanol as a solvent and acetylacetone as a modifier; and forming a seed layer for a electroactive film by spin coating the precursor solution on a substrate. The electroactive film can be PZT, PZO or BFO, spin-coated or inkjet printed on the seed layer. Experience shows pure orientation for the piezoelectric film thanks to the use of 1-methoxy-2-propanol when preparing the seed layer. This orientation is attributed to the formation of nano crystals on the seed layer constituting a pre-crystallization.

Proposed is a method for producing a polymeric piezoelectric composite having boron nitride nanotubes (BNNT) dispersed therein, the method including: a solution-providing step for providing a polymeric solution; a dispersing step for dispersing BNNT in the polymeric solution; and an electro spinning step for electro spinning the polymeric solution with BNNT dispersed therein, thereby producing micro- and/or nano fibers based polymeric piezoelectric composites.

An artificial tongue is provided. The artificial tongue includes tongue tissue formed by a bioprinting process, an antenna embedded within the tongue tissue and configured to wirelessly receive power from an external device, a processor embedded within the tongue tissue and operatively coupled to the antenna, and a piezoelectric element embedded within the tongue tissue and operatively coupled to the processor. The piezoelectric element is configured to deform in response to an applied electric bias, and the processor is configured to cause the electric bias to be applied to the piezoelectric element based on the power received by the antenna.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. Patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the electrodes and a planarized support layer is deposited over the sacrificial layer. The device can include a dielectric protection layer (DPL) that protects the piezoelectric layer from etching processes that can produce rough surfaces and reduces parasitic capacitance around the perimeter of the resonator when the DPL’s dielectric constant is lower than that of the piezoelectric layer. The DPL can be configured between the top electrode and the piezoelectric layer, between the bottom electrode and the piezoelectric layer, or both.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. Patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the electrodes and a planarized support layer is deposited over the sacrificial layer. The device can include a dielectric protection layer (DPL) that protects the piezoelectric layer from etching processes that can produce rough surfaces and reduces parasitic capacitance around the perimeter of the resonator when the DPL’s dielectric constant is lower than that of the piezoelectric layer. The DPL can be configured between the top electrode and the piezoelectric layer, between the bottom electrode and the piezoelectric layer, or both.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. A first patterned electrode is deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the first electrode and a planarized support layer is deposited over the sacrificial layer, which is then bonded to a substrate wafer. The crystalline substrate is removed and a second patterned electrode is deposited over a second surface of the film. The sacrificial layer is etched to release the air reflection cavity. Also, a cavity can instead be etched into the support layer prior to bonding with the substrate wafer. Alternatively, a reflector structure can be deposited on the first electrode, replacing the cavity.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. A first patterned electrode is deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the first electrode and a planarized support layer is deposited over the sacrificial layer, which is then bonded to a substrate wafer. The crystalline substrate is removed and a second patterned electrode is deposited over a second surface of the film. The sacrificial layer is etched to release the air reflection cavity. Also, a cavity can instead be etched into the support layer prior to bonding with the substrate wafer. Alternatively, a reflector structure can be deposited on the first electrode, replacing the cavity.

The present invention provides a surface tension assisted film forming method to prepare a flexible, patterned piezoceramic composite for use in a variety of electronics. The present method allows tuning mechanical and piezoelectric properties of the resulting composite by simply adjusting one or few parameters used during the piezoceramic film forming and/or composite forming procedures in the absence of any complex transferring techniques that are commonly used in conventional methods. The present invention also allows customizing patterns (two-dimensional or three-dimensional) on the piezoceramic framework to result in a piezoelectric composite that is able to provide anisotropic piezoelectric responses to different loads whilst still having a constant electrical output over a long-time deformation.