Smart System Applications Research Articles

Superelasticity in TiNi Alloys and Its Applications in Smart Systems

The superelasticity is one of the most important properties of TiNi alloy, which has been widely used in the smart systems of many fields, such as aerospace, aviation, biomedicine and energy etc. The current state of superelasticity of TiNi alloy has been reviewed with emphasis on the superelasticity, phase transformations, thermo-mechanical treatment and their relationship. The mechanisms of linear superelasticity and non-linear superelasticity have been revealed. Some successful applications based on the superelasticity of TiNi alloys in smart systems have been introduced.

743 白金コアを有する圧電セラミックファイバーの作製と評価

Piezoelectric materials are the most widely used functional materials for sensor and actuator applications in smart structural systems. Piezoelectric fibers developed a few years ago have been used for vibration suppression and noise reduction of smart structures. However piezoelectric fibers without a core must use inter-digital electrodes so that it is difficult to use a single fiber. This paper introduces the development of piezoelectric fibers with a metal core, which can be used as an electrode. When the other electrode is coated on the outer surface of the fiber by sputtering or using conductive paste, a single fiber can be used as a sensor or an actuator. The fabricated fibers were bonded on the surface of a composite beam and the sensor functions of the fibers was confirmed by measuring the output of the fibers during the vibration of the beam and the actuator function was confirmed by applying an external voltage to the fibers to excite the vibration of the beam.

Antiferroelectric thin films for MEMs applications

Antiferroelectric compositions have many potential applications in energy conversion and microelectromechanical systems. Electric field induced phase transitions between ferroelectric and antiferroelectric phases were studied in antiferroelectric lead zirconate and modified lead zirconate titanate stannate family thin films for various smart system applications. Thin films of various antiferroelectric thin film compositions such as PbZrO3, Nb-and La-modified Lead Zirconate Titanate Stannate were processed by pulsed excimer laser ablation technique. Dielectric, hysteresis, pyroelectric and switching properties were studied in detail for a new generation of functional materials. A comparative study of functional properties is presented with these antiferroelectric compositions in comparison with the conventional ferroelectric compositions.

Remarks on well-posedness theorems for damped second-order systems

We consider an operator theoretic formulation for distributed damped second-order (in time) forced linear elastic systems. A brief summary of previous well-posedness results is presented along with new results which allow relaxed spatial regularity (which is important in smart material systems applications) on the forcing or input function. Extensions to nonlinear systems are also indicated. The results are presented in a variational format for easy development of finite element approximation methods.

Smart Ferroelectric Films and Fibers; Applications in Micromechanics

ABSTRACTSmart electroceramics, in the form of ferroelectric thin films show great potential for applications in the field of microelectromechanical systems. Ferroelectric thin films will become a key player due to their optical, mechanical, electrical and thermal sensing with actuating capabilities. Recent results on electromechanical transduction in piezoelectric (e.g. PZT), electrostrictive (e.g. PLZT), and antiferroelectricferroelectric phase switching (e.g. PLZSnT) thin films and their potential applications in smart micromechanical systems are discussed. The possibility of three dimensional structures exists in the emerging technology of ferroelectric fibers. Some exciting applications for these films and fibers include microvalves, ultrasonic micromotors, microrobotic actuators and micropumps.

Twenty-First Century Truck Electronics—Today's Global Challenge

The main catalyst for use of state-of-the-art electronics in commercial trucks in the United States is the need to meet EPA emission standards for the 1990s. Important secondary catalysts are fuel economy, anti-lock brake systems and fleet/driver expectations. There are also myriad other forces related to safety, maintainability, servicing and communication which will be satisfied once electronic systems are installed in trucks. The principal economic justification for incurring the cost of electronics at this time is to satisfy these more stringent gaseous emission and particulate regulatory standards. Using electronics, these standards can be met without producing a severe reduction in fuel economy while, as a by-product, interfacing with other truck components, such as brakes, transmissions, safety controls etc. This paper will address the applications of electronics today for diesel engine controls as well as the applications of electronics in areas such as smart power switches, anti-jackknife controls, voice-recognition systems and other future system applications. The exploding use of electronics in trucks will require solutions to many complex problems which are not unique to any one company, geographic area, country or technical society.