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This paper presents the feasibility of using piezoelectric materials in a power source for micro-electro-mechanical systems (MEMS) devices. The finite element method (FEM) is adopted to evaluate the power generations of commercially available piezofilms that are subjected to a fluctuating pressure source (blood pressure). The accuracy of the results obtained from the FEM is verified by comparing with the corresponding results obtained from a theoretical analysis. In addition, an experiment is undertaken in order to evaluate the power generation of two different shapes of the piezofilms: square and circle. Finally, a brief discussion is made on the storage of experimentally harvested power and use of the MEMS applications.

In this work, the vibration control performance of an active mount using an electromagnetic actuator is experimentally evaluated. After manufacturing an electromagnetic actuator, dynamic characteristics such as the actuating force and response time of the electromagnetic actuator are experimentally investigated. The material properties of the rubber element are also experimentally identified. An active mount system using an electromagnetic actuator and a rubber element is designed and the governing equation is derived. A sliding mode controller that has inherent robustness to external disturbance is designed and implemented in the system. Vibration control performances of the active mount system, such as acceleration and transmitted force, are experimentally evaluated and they are presented in both time and frequency domains. It is observed that the structural vibration is effectively attenuated by applying proper control input to the electromagnetic actuator.

This work presents road test results for vibration control of a vehicle suspension system equipped with continuously controllable electrorheological (ER) shock absorbers. The test vehicle is a mid-sized passenger car whose suspension systems are typical Macpherson strut types for the front part and multilink types for the rear part. The four ER shock absorbers (two for the front suspension and two for the rear suspension) are devised based on design specifications for the test vehicle and their damping forces are experimentally evaluated with respect to the electric field. The ER shock absorbers and conventional spring elements are then assembled into suspension systems. Prior to undertaking the road test, the front ER suspension is applied to the quarter-car facility in order to validate control performance of the skyhook controller embedded in on-chip hardware. Subsequently, the full-vehicle model incorporating four ER suspensions is established and the skyhook control gains are determined in an optimal manner. The controller is then implemented on the test vehicle which is equipped with several sensors, a data acquisition system, and high-voltage amplifiers. Control performances are evaluated under various road conditions (bump, long waved, rugged, paved, and unpaved) and presented in both time and frequency domains.

This article presents position tracking control of a flexible beam using a piezoelectric actuator. This is achieved by implementing both a feedforward hysteretic compensator of the actuator and a proportional-integral-derivative (PID) feedback controller. The Preisach model is adopted to develop the feedforward hysteretic compensator. In the design of the compensator, estimated displacement of the piezoceramic actuator is used based on the limiting triangle database that results from collecting data of the main reversal curve and the first-order ascending curves. Modal parameters of the flexible beam, such as natural frequency, are obtained using a finite element method. Experimental implementation is conducted for position tracking control and performance comparison is made among an open-loop feedforward compensator, a PID feedback controller without considering the effect of hysteresis, and a PID feedback controller integrated with the feedforward hysteretic compensator.