This paper discusses the feasibility of a piezoelectric resonant pressure sensor made of lead–zirconate–titanate (PZT) thick films on a preprocessed 3D low‐temperature co‐fired ceramic structure with ...a deformable diaphragm. Numerical and experimental analyses were carried out. Two different thick‐film PZT compositions were characterized. Using experimentally evaluated material properties, a finite‐element analysis showed the trends and facilitated the decisions in the design phase of the sensor.
Purpose - The purpose of this paper is to consider a capacitive pressure sensor fabricated using low-temperature cofired ceramic (LTCC) materials and technology as a candidate for an ...energy-autonomous sensor application. Designing the 3D capacitive sensor structure, with the cofired thick-film electrodes inside the narrow air gap in the LTCC substrate, was a challenging task, particularly due to the presence of the parasitic elements influencing the sensor's characteristics.Design methodology approach - In this work, different design variants for the thick-film electrodes of the capacitive sensing structure were studied and compared. The test sensors were designed for the pressure range 0-10 kPa and manufactured with readout electronics based on a capacitance-to-digital conversion.Findings - The typical sensitivity obtained was 4 fF kPa, and the temperature coefficient of the sensitivity was 0.03% °C. The design variant with the guard-ring electrode showed the best rms resolution of 50 Pa. One drawback of the application could be the sensitivity to atmospheric humidity and the influence of the different media.Originality value - This paper focuses on the design of a capacitive gas-pressure sensor in a 3D LTCC structure. The present study provides a good basis for further optimisation of the design of the cofired electrodes in the capacitive sensing structure.
We present a combined experimental and numerical procedure for the characterisation of thick lead–zirconate–titanate (PZT) films, which was used to obtain the material parameters for a finite-element ...(FE) model of a thick-film quasi-static bending actuator. Due to the lack of standardised characterisation techniques for measuring the elastic and piezoelectric properties of thick piezoelectric films, non-conventional experimental techniques were implemented as follows: nano-indentation measurements were performed to evaluate the material compliance, and an adapted substrate-flexure method was used to measure the transverse piezoelectric coefficients of the thick PZT film. Good agreement between the results from the numerical and experimental analyses validated the model and confirmed the applicability of the proposed characterisation procedure.
Na koncertu, ki ga je Mestna občina Celje 23. junija 2011 soorganizirala z Osrednjo knjižnico Celje, so nastopili vokalni solisti: Sanja Poljšak Pesan, Manuela Brečko, Tomo Hartman, Sandra Petek, ...Tim Jevšenak in otroški zborček Male Žabe. Orkestru je dirigiral Roman Fonda.
Different piezoelectric materials can be used in micro-electro-mechanical systems (MEMS) for transducers i.e. actuators and sensors of mechanical quantities. Lead zirconate titanates (PZTs) are the ...most common ceramic materials used as piezoelectric transducers. The ceramic MEMS are made by LTCC (low temperature cofired ceramic) and thick-film technology. They have been extensively used due to their superior piezoelectric properties. The use of thick-film PZT materials on LTCC substrate is not a trivial task due to the interaction between the printed PZT layers and the LTCC substrates during firing. The microstructural, electrical and piezoelectric characteristics of the thick PZT films on relatively inert alumina substrates and on LTCC tapes were studied. To minimise the possible interactions between glassy LTCC substrates and active PZT films for some samples the intermediate barrier layers were used. To characterise the thick PZT films on ceramic substrate the dielectric permittivities (epsiv), dielectric losses (tgdelta), and piezoelectric coefficients (d 33 ) were measured. The thick-film piezoelectric resonant pressure sensor on LTCC structure was designed and samples were fabricated (Figure 2). The thick-film PZT actuator on the ceramic diaphragm induces the vibration of the diaphragm at its resonant frequency. The applied pressure bends the diaphragm and generates additional stress, which shifts the resonant frequency. This is used as the output signal of the piezoelectric resonant pressure sensor. The resonant frequencies are shifted around 26 kHz. The calculated sensitivities are 2.5 Hz/kPa.
This article describes the implementation of early warning feature in an over-current protection module designed for limiting the surge-current in communication applications. The early warning signal ...is generated by a surge-current sensor and a temperature sensor mounted on the protection module. Described solution decreases fault latency and consequently improves the efficiency of the on-line fault detection mechanism. It can be used for diagnostic on-line monitoring in dependable adaptive computing systems.
Domoznanski oddelek celjske knjižnice pripravlja že četrto leto zanimive domoznaske vsebine za časopis Novi tednik, ki ima stalno rubriko Zgodbe iz Kamre, v kateri v nadaljevanjih s partnerji na ...območju objavlja na tem portalu že objavljene zgodbe. Sodelovanje s časopisom se je začelo leta 2010 ob zaključku projekta digitalizacije časopisa Novi tednjik z njegovimi predhodniki in objave v Digitalni knjižnici Slovenije.
V Osrednji knjižnici Celje je od 15. janurja do 28. februarja na ogled razstava o zgodovini celjske cinkarne. Med obiskovalci razstave so tudi zaposleni v Cinkarni. Tudi bivši, kot je gospod Jože ...Počivalšek (na fotografiji) iz Olimja, ki je bil v Cinkarni Celje zaposlen v letih 1967-1968 in 1982-2002 v obratih Titan – Žveplena kislina.
