An apparatus and methods to make a product using supersonic cold-spray deposition of brittle functional materials in fine and micro features down to 10 μm in minimum dimension. The process may use semiconductors such as bismuth and antimony telluride formulations, and hard magnetic materials such as neodymium iron boride and strontium ferrite, and soft magnetic materials such as manganese zinc ferrite, and manganese ferrite materials. In addition, the methods and processes have been demonstrated for materials as soft as graphite and as hard as boron carbide. Micro components have been deposited in square, tapered and elongated shaped features with feature sizes as small as 10 μm in minimum dimensions and applied to flat and highly complex shaped surfaces. This process when combined with other cold spray manufacturing processes allows the total additive manufacturing of complete electronic, magnetic and other complex devices including multiple type of brittle functional materials.

In some embodiments, the present disclosure relates to a method for recovering degraded device performance of a piezoelectric device. The method includes operating the piezoelectric device in a performance mode by applying one or more voltage pulses to the piezoelectric device, and determining that a performance parameter of the piezoelectric device has a first value that has deviated from a reference value by more than a predetermined threshold value during a first time period. During a second time period, the method further includes applying a bipolar loop to the piezoelectric device, comprising positive and negative voltage biases. During a third time period, the method further includes operating the piezoelectric device in the performance mode, wherein the performance parameter has a second value. An absolute difference between the second value and the reference value is less than an absolute difference between the first value and the reference value.

Chemical sensors include a functionalized electrode configured to change surface potential in the presence of an analyte. A piezoelectric element is connected to the functionalized electrode. A piezoresistive element is in contact with the piezoelectric element.

A vibrating body includes a substrate, a piezoelectric element comprising a piezoelectric layer and electrode layers and joined to the substrate, and a ceramic layer between the substrate and the piezoelectric element. The ceramic layer comprises a first region and a second region which is adjacent to the first region in a direction perpendicular to a thickness direction of the ceramic layer. The first region has a square shape, each side of the first region having a length equal to a thickness of the ceramic layer, the second region has a square shape, each side of the second region having the length equal to the thickness of the ceramic layer, and a difference between a porosity of the first region and a porosity of the second region is not greater than 15%.

A vibration element includes: a substrate; a ceramic layer containing molten glass and provided on the substrate; and a piezoelectric element fixed to the substrate with the ceramic layer therebetween, wherein the piezoelectric element includes a first electrode layer provided in contact with the ceramic layer, a second electrode layer, and a piezoelectric layer provided between the first electrode layer and the second electrode layer, and the first electrode layer has a thickness larger than that of the second electrode layer.

A thin film X.sub.yAl.sub.(1-y)N alloy preferably deposited with an intrinsic tensile stress significantly enhances the piezoelectric properties of AlN. The alloy contains y percent of the compound XN, where X is selected from the group consisting of Yb, Ho, Dy, Lu, Tm, Tb, and Gd. The percentage of XN preferably lies in the range 10-60%, and the stress is preferably in the range 200 MPa-1.5 GPa. The film is useful in MEMS devices.

Provided is a piezoelectric film that has a perovskite structure preferentially oriented to a (100) plane and that comprises a composite oxide represented by the following compositional formula: Pb.sub.a[(Zr.sub.xTi.sub.1-x).sub.1-yNb.sub.y].sub.bO.sub.3 wherein 0<x<1, and 0.10≤y<0.13, in which in a case where a ratio I.sub.(200)/I.sub.(100) of a diffraction peak intensity I.sub.(200) from a perovskite (200) plane with respect to a diffraction peak intensity I.sub.(100) from a perovskite (100) plane, as measured by an X-ray diffraction method, is r, and a/b is q, 0.28r+0.9≤q≤0.32r+0.95, 1.10≤q≤1.25, and r≤1.00 are satisfied.

There is provided a piezoelectric laminate, including: a substrate; and a piezoelectric film formed on the substrate, wherein the piezoelectric film is a film containing an alkali niobium oxide of a perovskite structure represented by a composition formula of (K.sub.1-xNa.sub.x)NbO.sub.3 (0<x<1), and having Young's modulus of less than 100 GPa.

An inkjet printing head 1 includes an actuator substrate 2 having pressure chambers (cavities) 7, a movable film formation layer 10 including movable films 10A disposed above the pressure chambers 7 and defining top surface portions of the pressure chambers 7, and piezoelectric elements 9 formed above the movable films 10A. Each piezoelectric element 9 includes a lower electrode 11 formed above a movable film 10A, a piezoelectric film 12 formed above the lower electrode 11, and an upper electrode 13 formed above the piezoelectric film 12. The piezoelectric film 12 includes an active portion 12A with an upper surface in contact with a lower surface of an upper electrode 13 and an inactive portion 12B led out in a direction along a front surface of the movable film formation layer 10 from an entire periphery of a side portion of the active portion 12A and having a thickness thinner than that of the active portion 12A.

A structural health monitoring method includes directly forming an acoustic transducer on a surface of a structure to be monitored; generating, by the acoustic transducer, an acoustic wave to apply stress loading to a region of interest on the structure; and detecting a presence of a defect in the region of interest. Detecting includes a non-contact optical imaging of the region of interest with and without the stress loading and an analysis of imaging data from the non-contact optical imaging.