A method includes receiving, by a piezoelectric stack of a transducer, a first piezoelectric voltage. The transducer has a base structure and a first layer, the base structure having a first displacement between a first portion of the base structure and the first layer. The method also includes transmitting, by the transducer, a first ultrasound frequency while receiving a first piezoelectric voltage, and receiving, by the transducer, a first bias voltage. The received first bias voltage alters the first displacement between the first portion of the base structure and the first layer, and the altered first displacement is smaller than the first displacement. The method further includes receiving, by the piezoelectric stack of the transducer, a second piezoelectric voltage to the transducer, and transmitting, by the transducer, a second ultrasound frequency while receiving the first bias voltage and the second piezoelectric voltage.

A method of making a bimorph assembly by stacking a perforated outer bottom metal layer, a transductive element, a perforated central metal layer, a second transductive element, and a perforated outer top metal layer to form a laminar structure, the metal layers and transductive elements being separated by thin conductive ink layers. Applying uniform and continuous pressure to the bottom and top surfaces of the laminar structure. Thermal cycling the laminar structure according to a thermal profile that causes suffusion of the thin conductive ink layers into the metal perforations and the transductive element surface. Removing the pressure from the bottom and top surfaces of the laminar structure and applying an electric field to the central metal layer, the outer top metal layer, and the outer bottom metal layer.

A transducer, a transduction apparatus, and a terminal are provided, and belong to the field of device technologies. The transducer includes a substrate layer, a first electrode layer, a piezoelectric layer, a second electrode layer, a first protective layer, and a second protective layer that are sequentially arranged. A sum of target parameters of the piezoelectric layer, the second electrode layer, the first protective layer, and the second protective layer is a positive integer multiple of n, where 0.1n0.4. A target parameter of at least one of the film layers in the transducer is a ratio of a thickness of the at least one film layer to a wavelength of a sound wave at an operating frequency of the transducer when the sound wave is transmitted at the at least one film layer.

A device, system and method for protecting electronic systems from failure or damage when such systems are subjected to undesired conducted or radiated energy such as electromagnetic pulse or electromagnetic interference. The invention also reduces the amount of conducted or radiated emissions from an electronic system. A novel, non-conductive signal feedthrough allows a desired signal to be communicated with electrical connectivity. An incoming desired electrical signal is converted to vibrational energy by a piezoelectric transducer, which is communicated into the interior volume of a conductive electrical enclosure housing a system to be protected, where it is converted back to electrical for processing by the system to be protected by a second piezoelectric transducer. The signal feedthrough allows a continuous conductive enclosure to be employed, providing protection from undesired radiated energy. The signal feedthrough allows communication without requiring electrical conduction through the feedthrough, thus protecting against undesired conducted energy.

A wafer level ultrasonic device includes a composite layer, a first conductive layer, a second conductive layer, a base, a first electrical connection region, and a second electrical connection region. The composite layer includes an ultrasonic element and a protective layer. The ultrasonic element includes a first electrode and a second electrode. The protective layer has a first connecting channel and a second connecting channel respectively corresponding to the first electrode and the second electrode. The first conductive layer and the second conductive layer are respectively in the first connecting channel and the second connecting channel to connect the first electrode and the second electrode. The base includes an opening forming a closed cavity with the protective layer. The first electrical connection region and the second electrical connection region are respectively filled with metal materials to electrically connect the first conductive layer and the second conductive layer.

A converting element for converting between mechanical vibrations and electric signals comprises piezoelectric elements arranged in a stack and a connector, for example a wire. At the outside of the stack are grooves between adjacent piezoelectric elements. The connector is disposed within the grooves which are filled with an electrically conductive filling material. The connector is connected to the stack via a sintering process. The connector comprises inner segments arranged within the grooves and outer segments arranged outside of the grooves. The outer segments are arranged at the outside of the stack. A vibronic sensor may contain the converting unit.

A manufacturing method of a wafer level ultrasonic device includes: forming a first piezoelectric material layer, a first electrode material layer, a second piezoelectric material layer, and a second electrode material layer in sequence on a substrate; removing parts of those layers to form an ultrasonic element including a first electrode and a second electrode; forming a first protective layer on the ultrasonic element, and forming a first through hole and a second through hole exposing a part of the first electrode and a part of the second electrode; forming a first conductive layer and a second conductive layer on the first protective layer and connecting to the first electrode and the second electrode; forming a second protective layer; and connecting a base with an opening and the second protective layer in a vacuum environment to form a closed cavity.