Search for dissertations about: "piezoelectric effect"

Showing result 6 - 10 of 41 swedish dissertations containing the words piezoelectric effect.

2. 6. Detecting Inclusions in a Silicone Rubber Phantom Using Standing Lamb Waves and Multiple Frequency Footprints

   Author : Ulf G Jonsson; Britt Andersson; Olof A Lindahl; Jacques Ohayon; Umeå universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Piezoelectric; Silicone rubber; Impedance; Resonance; Lamb waves; Phantom; Electronics; elektronik;

   Abstract : The thesis deals with one major question: is it possible, using one piezoelectric sensor/vibrator, to detect a hard inclusion in a silicone rubber phantom? The question was approached with an open mind and the task was subdivided into three clearly identifiable parts: characterization of the piezoelectric sensor/vibrator (paper I), creating a model of the visco-elastic properties of a tissue-like material (phantom) in contact with the sensor/vibrator (paper II), and to detect the presence of a hard inclusion in the phantom (paper III). All vibrations of the sensor/vibrator and phantom was modeled using a finite element method (FEM). READ MORE

4. 7. Switchable and tunable bulk acoustic wave resonators based on BaxSr1-xTiO3 thin films

   Author : John Berge; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ferroelectric thin films; field induced piezoelectric effect.; tunable microwave devices; bulk acoustic wave devices; piezoelectric resonators;

   Abstract : The main focus of this thesis is the study of a novel microwave component, the tunable thin film bulk acoustic wave resonator (TFBAR), based on ferroelectric BaxSr1-xTiO3 thin films. Conventional fixed frequency TFBARs, widely used for filtering applications in wireless communication systems, are based on ordinary piezoelectrics. READ MORE

5. 8. Vibrational energy harvesting for sensors in vehicles

   Author : Johan Bjurström; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; piezoelectric; anti-resonance; electromagnetic induction; prescribed displacement; low frequency; nonlinear dynamics; small amplitude excitation; automotive safety; vibration energy harvesting; unified modeling;

   Abstract : The miniaturization of semiconductor technology and reduction in power requirements have begun to enable wireless self-sufficient devices, powered by ambient energy. To date the primary application lies in generating and transmitting sensory data. READ MORE

6. 9. Enzyme Printed Fabrics : Bio‐functionalisation of Synthetic Textiles by Digital Inkjet Printing

   Author : Tuser Biswas; Vincent Nierstrasz; Junchun Yu; Tzanko Tzanov; Högskolan i Borås; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Digital printing; inkjet; enzyme; printhead; rheology; immobilisation; piezoelectric; drop-on-demand; resource-efficient textiles; biological ink; lysozyme; tyrosinase; polyphenol oxidase; polyethylene terephthalate; polyester; polyamide-6; 6; nylon; surface modification; plasma; antimicrobial; antibacterial; Textil och mode generell ; Textiles and Fashion General ;

   Abstract : This thesis explores the possibilities of printing enzymes using resource-efficient technologies to promote the binding of other proteins and biomaterials on synthetic textiles. This strategy can be used to develop advanced textiles for applications, for example, in antimicrobial, drug delivery and biosensing. READ MORE

7. 10. On the Frequency and Q Factor Response of the Quartz Crystal Microbalance to Liquid Overlayers

   Author : Michael Rodahl; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; piezoelectric effect; solid-liquid interface; sensors; protein adsorption; QCM; tribology; quartz crystal microbalance;

   Abstract : The quartz crystal microbalance (QCM) is an ultra-sensitive weighing device. It consists of a piezoelectric quartz crystal, often in the form of a disk, which is sandwiched between a pair of evaporated electrodes. READ MORE