OSEA2014-tag2

PZT piezoelectric ceramics have high Curie temperature due to the piezoelectric strong, easy doping, good stability, since the 1960s, has been the focus of attention and research in the field of piezoelectric ceramics dominant. 


OSEA2014-tag2

This article explores a new simple method, the piezoelectric ceramic diaphragm cochlear implants, the use of materials, piezoelectric effect, the acoustic signals into electrical signals directly stimulate the auditory nerve to Xin replace expensive, complex electronic cochlea so deaf ear to regain hearing which will benefit hundreds of foolproof deaf patients. 

OSEA2014-tag2

In recent years, research and hydrothermal method in the field of lead-free piezoelectric ceramics focused on lead-free piezoelectric ceramic powder synthesis, and thus the powder system for ceramic piezoelectric properties have been reported rarely, and therefore still the need for further research. 

OSEA2014-tag2

Sodium bismuth titanate (Bi1 / 2Na1 / 2TiO3), referred to as the BNT, is considered a possible lead-based piezoelectric ceramics to replace lead-free piezoelectric ceramic system, it is A bit complex ions such as calcium titanium invented by Smolensky mine ferroelectrics, ferroelectric strong, good piezoelectric properties, low dielectric constant and good acoustic properties and other excellent features, and low sintering temperature, which is being widely studied. 

OSEA2014-tag2

The past 20 years, the non-lead-based piezoelectric ceramics has been great development, some good system performance in low-end and midrange products have been practical. Currently there are lead-free piezoelectric ceramics system BaTiO3 (referred to as BT) based lead-free piezoelectric ceramics, alkali metal niobate-based lead-free piezoelectric ceramics, tungsten bronze structure lead-free piezoelectric ceramics, lead-free piezoelectric bismuth layer structure ceramics and BNT-based lead-free piezoelectric ceramics and other types. Which BNT strong due to the ferroelectric piezoelectric coefficient, good acoustic performance advantages and favored. 

OSEA2014-tag2

Audio directional speakers in the industry, also known as beam speaker (Audio beam loudspeaaker), Audio Spotlight (Audio spotligth), ultrasonic frequency sound system (Hypersonic sound system), directional acoustic system (directional acoustics systerm), parametric speaker (parametric loudspeaker ), parametric acoustic array (parametric acoustics array), etc., as a new speaker is currently no unified name. 

OSEA2014-tag2

Piezoelectric ceramics as an important functional materials has been more widely used. Piezoelectric ceramics by polarized ferroelectric ceramics obtained. The ferroelectric ceramics potential applications of piezoelectric polarization process by improving the ability to obtain adequate mining, has become a topic of great interest to people. 

OSEA2014-tag2

The piezoelectric transducer is a key component of the acoustic logging tool, for transmitting and receiving acoustic signals. In the logging tool, the piezoelectric transducer is usually paired use. 

OSEA2014-tag2

 Horizontal - vertical-type piezoelectric ceramic transformer equivalent circuit shown in Figure 2. Figure Y, O is representative of the desired input terminal of the transformer, the output transformer ratio, and it is the geometry of the piezoelectric constant of the piezoelectric ceramic material is determined. C01, C02 denote capacitors much lower than the free resonance frequency of the transformer (1KHZ) measured at the input terminal of the piezoelectric ceramic transformer and an output terminal. L0, C0, and R0 is the resonance frequency of the piezoelectric transformer in the vicinity of the concentration of the mechanical parameters of the system, respectively, the equivalent inductance, and the equivalent impedance of the equivalent capacitance. 

OSEA2014-tag2

Sonic transmitter need to provide a sufficiently large transducer excitation signal, otherwise the receiver will be unable to detect the probe from the formation of the back reflection acoustic signals, the maximum of the excitation pulse voltage of up to several RV. Moreover, it should be between the driving circuit and the transducer impedance matching, the energy of the excitation pulse can be effectively transmitted to the transducer. 

OSEA2014-tag2

 Piezoelectric ceramic speakers, also called crystal speakers, mainly the surface of the piezoelectric film without damage, cracking; whether sealing off the lead, Weld. 

OSEA2014-tag2

 the parallel resonance frequency fp (parallel resonance frequency): an equivalent circuit of the piezoelectric transducer resonance frequency of the parallel branch is called the parallel resonant frequency, represented by fp, i.e. fp =