A through hole (3) is provided on a supporting substrate (2). A plate-shaped beam (4) extends from an edge of the through hole (3) to a facing edge in such a way as to cover part of the through hole (3) and is provided with a piezoelectric element. A drive electrode (16) vibrates the beam (4) by applying voltage to the piezoelectric element. Detection electrodes (17A, 17B) detect information about the vibration frequency of the beam (4). Substance adsorption films (5A, 5B) change the vibration frequency of the beam (4) by adhesion of a substance. The substance adsorption films (5A, 5B) and the detection electrodes (17A, 17B) are respectively provided at the same position on the front and the back of the beam (4).

A vibrational multi-morph piezoelectric energy harvester includes a composite shim having a parallelepiped form with a thickness dimension made smaller than width and length dimensions, and having a stiffness shifting from one extremity to the other extremity to minimize mechanical constraints developed at a clamping area; a seismic mass mounted at an end opposite to the clamping area to mechanically match the system to the surrounding vibration resonance; one or more piezoelectric layers laminated on said composite shim; and electrodes plated onto the one or more piezoelectric layers for connection to an electronic harvesting circuit, a battery, or a super capacitor.

A hybrid document includes a flexible document having visible markings. One or more light-controlling elements and a controller are embedded in or on the flexible document. The controller is electrically connected to the one or more light-controlling elements to control the one or more light-controlling elements. A power input connection is electrically connected to the controller, or one or more light-controlling elements, or both. A power source can be connected to the power input connection, for example a piezoelectric or photovoltaic power source. In response to applied power, the controller causes the one or more light-controlling elements to emit light. In some embodiments, the controller includes a memory and a value can be stored in the memory and displayed by the light-controlling element(s). In some embodiments, the value can be assigned or varied by a hybrid currency teller machine.

The module comprises a pendular unit with an elastically deformable piezoelectric beam having a clamped end and an opposite, free end, coupled to an inertial mass. The beam produces an oscillating electrical signal collected by electrodes, which is rectified and regulated to output a voltage for charging a battery. The number and configuration of the electrodes (T1, T2, B1, B2, N) carried by the piezoelectric beam define a plurality of pairs of electrodes between which a corresponding plurality of said oscillating signals can be simultaneously collected. A switching matrix, as a function of an input command, selectively switches the plurality of pairs of electrodes between each other according to a plurality of different series (S), parallel (P) and/or series-parallel (SP) configurations, the selected configuration being that which maximizes the power sent to the battery as a function of the voltage level (VBAT) present at the terminals of the latter.

A piezoelectric element includes: a vibration unit that outputs a pressure detection signal according to a pressure; a support member; and an improvement unit for improving a detection accuracy of the pressure detection signal. The vibration unit on the support member includes a piezoelectric film and an electrode film in a support region and vibration regions. Each vibration region has one end portion as a fixed end and an other end portion as a free end. A part of each vibration region on a one end portion side is a first region, and another part of each vibration region on an other end portion side is a second region. The electrode film is disposed in the first region.

The invention provides a compound-pendulum up-conversion wave energy harvesting apparatus, comprising a shell floating on the water surface and swinging with fluctuation of waves, a compound-pendulum mechanism rotatably arranged in the shell and rotating with its swinging, a driving gear rotatably arranged in the shell and rotating synchronously with the compound-pendulum mechanism, an electromagnetic power generation mechanism arranged in the shell and configured to be meshed with the driving gear for transmission to generate electricity through electromagnetic induction, and a piezoelectric power generation mechanism arranged in the shell and configured to be deformed during its rotation to generate electricity through piezoelectric effect. When the shell swings un-directionally with fluctuation of the waves, the compound-pendulum mechanism makes un-directional rotation that adapts to the dynamic changes of water surface wave energy. The electromagnetic power generation mechanism and the piezoelectric power generation mechanism convert energy through two different electromechanical coupling transduction mechanisms.

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.

A self-powered sensor node includes a printed wiring board connected to a patch. The printed wiring board includes a microcontroller, a transceiver, an antenna, and a power management module connected to supply electric power to the microcontroller. The patch comprises a metamaterial substrate and a piezoelectric element adhered to the metamaterial substrate. The piezoelectric element is connected to the power management module and to the microcontroller. The power management module is configured to store electric power received from the piezoelectric element. The microcontroller is configured to selectively convert electrical signals received from the piezoelectric element into sensor data and then command the transceiver to transmit the sensor data via the antenna. The metamaterial substrate has an auxetic kirigami honeycomb structure.

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.

The present disclosure relates to a wind power generator using a piezoelectric element. A wind power generator using a piezoelectric element according to an embodiment of the present disclosure, includes: a plurality of panels which are sequentially stacked, a wing-shaped piezoelectric member disposed between the plurality of panels for generating electrical energy by external force and a vibrating ball container disposed on one surface of the wing-shaped piezoelectric member and including a plurality of vibrating balls, wherein a hole through which wind can pass is formed in at least one surface of the vibrating ball container.