A method includes converting an electrical output provided by an energy generator with a first voltage converter; and, subsequent to converting the electrical output provided by the energy generator with the first voltage converter, activating, with a microprocessor, a second voltage converter for converting the electrical output provided by the energy generator with the second voltage converter. An electrical device with a microprocessor for selecting one of two or more voltage converters is also described.

A molecular detection apparatus includes a detector. The detector includes: a vibrator having a piezoelectric member that has a first surface and a second surface, a first electrode connected to the first surface, a second electrode connected to the second surface, and a third electrode connected to the second surface and disconnected from the second electrode; a sensitive film overlapping at least one part of the second electrode and at least one part of the third electrode and configured to change a vibration frequency of the vibrator in response to an interaction with target molecules; and a detection electrode to detect the changed vibration frequency.

A transducer includes a first piezoelectric layer; and a second piezoelectric layer that is above the first piezoelectric layer; wherein the second piezoelectric layer is a more compressive layer with an average stress that is less than or more compressive than an average stress of the first piezoelectric layer.

A RF antenna or sensor has a substrate, a resonator operable at UHF disposed on the substrate, the resonator preferably having a quartz bar or body with electrodes disposed on opposing major surfaces thereof and with a magnetostrictive material disposed on or covering at least one of the electrodes. A pair of trapezoidal, triangular or wing shaped high permeability pole pieces preferably supported by that substrate are disposed confronting the resonator, one of the pair being disposed one side of the resonator and the other one of the pair being disposed on an opposing side of said resonator, the pair of high permeability pole pieces being spaced apart by a gap G, the resonator being disposed within that gap G. The size of gap G is preferably less than 100 μm.

A piezoelectric element and a method of manufacturing the piezoelectric element are provided. The piezoelectric element is provided with a substrate having an intermediate layer disposed between a first substrate layer and a second substrate layer, a first electrode layer of an electrically conductive non-ferroelectric material disposed on the second substrate layer, a ferroelectric, piezoelectric and/or flexoelectric layer disposed on the first electrode layer, and a second electrode layer of an electrically conductive non-ferroelectric material disposed on the ferroelectric, piezoelectric and/or flexoelectric layer. The intermediate layer and/or the first substrate layer is removed below a layer stack formed by the first electrode layer, the ferroelectric, piezoelectric and/or flexoelectric layer, and the second electrode layer so that the layer stack can be moved in a translatory manner along its normal directed along the layer sequence.

A movable piezo element and to a method for producing the element are provided. The movable piezo element may have a structured substrate, in which an intermediate layer is arranged between a first substrate layer and a second substrate layer. The element may also have a first electrode layer. The element may also have a second electrode layer arranged on the ferroelectric, piezoelectric, or flexoelectric layer. The second substrate layer may be structured such that at least one bar of the second substrate layer is formed. The bar may be clamped on one side and may be physically spaced from the first substrate layer. A surface of the bar facing away from the first substrate layer, and/or a lateral surface of the bar, may be at least partly covered by another layer.

A cooling system is described. The cooling system includes a support structure, a cooling element, and drive electronics. The cooling element has a central axis and is supported by the support structure at the central axis. First and second portions of the cooling element are on first and second sides of the central axis and unpinned. The first and second portions of the cooling element undergo vibrational motion when actuated to drive a fluid toward a heat-generating structure. The cooling element further has first and second piezoelectrics having opposite polarizations. The first piezoelectric is part of the first portion of the cooling element. The second piezoelectric is part of the second portion of the cooling element. The drive electronics drive the first and second portions of the cooling element using a single drive signal.

A smart ring is configured harvest mechanical energy using piezoelectricity. The smart ring includes a ring-shaped housing, a power source disposed within the ring-shaped housing, and a charging circuit. The charging circuit includes a piezoelectric harvesting element, and is configured to charge the power source when user motion causes a mechanical deformation in the piezoelectric harvesting element. The smart ring further includes a component, disposed within the ring-shaped housing and configured to draw energy from the power source, and further configured to perform at least one of: i) sense a physical phenomenon external to the ring-shaped housing, ii) send communication signals to a communication device external to the ring-shaped housing, or iii) implement a user interface.

A metamaterial-based substrate (meta-substrate) for piezoelectric energy harvesters. The design of the meta-substrate combines kirigami and auxetic topologies to create a high-performance platform including preferable mechanical properties of both metamaterial morphable structures. The creative design of the meta-substrate can improve strain-induced vibration applications in structural health monitoring, internet-of-things systems, micro-electromechanical systems, wireless sensor networks, vibration energy harvesters, and other applications whose efficiency is dependent on their deformation performance. The meta-substrate energy harvesting device includes a meta-material substrate comprising an auxetic frame having two kirigami cuts and a piezoelectric element adhered to the auxetic frame by means of a thin layer of elastic glue.

An ultrasound transducer of a vehicle system includes a support member that attaches to and connects to the bottom portion of a membrane of the ultrasound transducer and supports the membrane, wherein the support member includes one or more cantilevers with a first end attaching to the membrane and a second end attaching to a support portion of the support member that attaches to the substrate, wherein the cantilever extends across and floats above the substrate, wherein the first end of the cantilever includes a stub extending away from a surface of the cantilever, wherein the stub extends away from the surface without contacting the substrate, wherein the one or more cantilevers includes one or more piezoelectric layers on the surface of the cantilever.