Development of Porous Piezoceramics for Medical and Sensor Applications
نویسندگان
چکیده
The use of porosity to modify the functional properties of piezoelectric ceramics is well known in the scientific literature as well as by the industry, and porous ceramic can be seen as a 2-phase composite. In the present work, examples are given of applications where controlled porosity is exploited in order to optimise the dielectric, piezoelectric and acoustic properties of the piezoceramics. For the optimisation efforts it is important to note that the thickness coupling coefficient kt will be maximised for some non-zero value of the porosity that could be above 20%. On the other hand, with a good approximation, the acoustic velocity decreases linearly with increasing porosity, which is obviously also the case for the density. Consequently, the acoustic impedance shows a rather strong decrease with porosity, and in practice a reduction of more than 50% may be obtained for an engineered porous ceramic. The significance of the acoustic impedance is associated with the transmission of acoustic signals through the interface between the piezoceramic and some medium of propagation, but when the porous ceramic is used as a substrate for a piezoceramic thick film, the attenuation may be equally important. In the case of open porosity it is possible to introduce a liquid into the pores, and examples of modifying the properties in this way are given.
منابع مشابه
Studying the effects of adding CeO2 and CuO on electrical properties of lead free (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 piezoceramics
Lead-free (Ba0.85Ca0.15)[(Zr0.1Ti0.9)]O3 (BCZT) piezoceramics were synthesized using solid-state ceramic processing. In order to improve the electrical properties CeO2 and CuO additives/dopants were used and two methods were employed to introduce theses oxides; one, in which 0.1 mol.% CeO2 was mixed with the raw materials and the composition was balanced for A-site substitution (BCCe0.1ZT) and ...
متن کاملRoom Temperature Methanol Sensor Based on Ferrite Cobalt (CoFe2O4) Porous Nanoparticles
In this work, porous nanoparticles of ferrite cobalt were prepared by dissolving CoCl2.6H2O and FeCl3 in ethylene glycol in a hydrothermal process. Using ethylene glycol instead of DI water as a solvent would cause to provide porous structure of ferrite cobalt. 0.05 ml of colloidal fluid of fabricated nanostructure was injected on interdigitated electrodes (IDE) on a printed circuit board (PCB)...
متن کاملDesign, Modeling, and Construction of a New Tactile Sensor for Measuring Contact-Force
This paper presents the design, modeling, and testing of a flexible tactile sensor and its applications. This sensor is made of polymer materials and can detect the 2D surface texture image and contact-force estimation. The sensing mechanism is based on the novel contact deflection effect of a membrane. We measure the deflection of the membrane with measuring the strain in the membrane with emb...
متن کاملA Priority-based Routing Algorithm for Underwater Wireless Sensor Networks (UWSNs)
Advances in low-power electronics design and wireless communication have enabled the development of low cost, low power micro-sensor nodes. These sensor nodes are capable of sensing, processing and forwarding which have many applications such as underwater networks. In underwater wireless sensor networks (UWSNs) applications, sensors which are placed in underwater environments and predicted ena...
متن کاملPerforming a Calcium-Phosphate Layer on Porous NiTi Alloy for Using in Orthopedic Applications
Porous NiTi alloys has a series of unique properties such as shape memory effect, superelastic behavior and energy absorbability that make them usable in a wide range of medical and industrial appliances. But the more probability of Ni release from a porous NiTi compare to the nonporous one has restricted it’s uses in implants. In the present research for resolving the problem, performing a cal...
متن کامل