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This paper presents a new low-cost method for calibration of microelectromechanical system accelerometers. A guide way with low friction that can provide a one-directional linear transversal motion is used. For collecting data sets, the accelerometer is moved manually from one reference point to another, and this movement is measured. A function is developed that relates this movement to acceleration. To verify the proposed calibration method, a three-axis table is used to collect data sets and a least-squares algorithm is applied to find the appropriate function. With this low-cost method, the scale factor matrix, the sensitivity matrix, the non-linear scale factor matrix and bias vector are found.

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In the conventional mechanical micropumps, the motion from one component (such as gear or diaphragm) produces pressure difference, which is needed to move fluid. In this paper, we propose a new method to use double PZT layers as an actuator for a valveless micropump, which is designed for pumping blood. Due to the high surface tension of blood, one PZT actuator is not strong enough to produce sufficient displacement. So instead of one PZT layer, a double-PZT layer is utilized to produce movement force. In this research, the analytic equations of a double circular PZT layer are derived to express the natural frequency of the system. The finite element method (FEM) simulation is utilized to verify the analytic equations. Then the required input voltage is applied to maximize the functionality of the system, whose simulation results are compared with the experimental measurement setup. Finally, a typical valveless micropump with the proposed double PZT layer is simulated by using COMSOL Multiphysics software. The flow rate of this configuration is compared with a single PZT actuator to demonstrate the effect of the proposed double-PZT actuator on the application to the valveless micropumps.

In this paper, we propose a new method to use cost-effective multi-sheet off-the-shelf piezoelectric material (e.g. PZT) as an actuator for micropumps. Instead of one customized single PZT sheet that is typically expensive, multiple commercially available PZT sheets are utilized to decrease the cost of fabrication. For this purpose, we have derived analytic equations for expressing the natural frequency and mode shape of the actuator. The FEM simulations are utilized to verify the analytic equations. Thanks to their high accuracy, we can utilize the derived analytic equations as fitness functions of genetic algorithm (GA) for the optimization purpose of PZT physical aspects. Our experimental measurement results show that the GA is capable of optimizing multiple physical parameters of the piezoelectric actuator. Moreover, one-way compliant microflaps are presented for the first time to act as one-way valves for a PZT micropump aided by our proposed multi-sheet PZT actuator. The flow rate of this configuration is compared with a single-sheet PZT actuator in order to demonstrate the effect of the optimized PZT actuators in the practical applications of micropumps.