Design, Modeling, and Analysis of Piezoelectric-Actuated Device for Blood Sampling

In recent years, micro electro-mechanical system (MEMS)-based biomedical devices have been investigated by various researchers for biomedicine, disease diagnosis, and liquid drug delivery. The micropump based devices are of considerable significance for accurate drug delivery and disease diagnosis. In the present study, design aspects of the piezoelectric actuated micropump used for extraction of blood sample are presented. A pentagonal microneedle, which is an integral part of the micropump, was used to extract the blood volume. The blood was then delivered to the biosensor, located in the pump chamber, for diagnosis. The purpose of such low-powered devices is to get sufficient blood volume for the diagnostic purpose at the biosensor located within the pump chamber, with a minimum time of actuation, which will eventually cause less pain. ANSYS® simulations were performed on four quarter piezoelectric bimorph actuator (FQPB) at 2.5 volts. The modal and harmonic analysis were carried out with various load conditions for FQPB. The extended microneedle lengths inside the pump chamber showed improved flow characteristics. Enhanced volume flow rate of 1.256 µL/s was obtained at 22,000 Hz applied frequency at the biosensor location.

Opto-mechanical modeling and experimental implementation of an FBG-based piezoelectric bimorph actuator for high voltage sensing applications

This paper proposes a highly simplified optical voltage sensor by using a piezoelectric bimorph and a Fiber Bragg Grating (FBG) that can be used for high voltage applications with a relatively good accuracy and stability. In this work the theoretical framework for the whole opto-mechanical operation of the optical sensor is detailed and compared to experimental results. In the analysis, a correction term to the electric field is derived to account for the linear strain distribution across the piezoelectric layer improving the designing equations and giving more criteria for future developments. Finally, some experimental results from a laboratory scale optical-based high voltage sensing setup are discussed, and shown to be in excellent agreement with theoretical expected behavior for different voltage magnitudes.

A piezo driver for piezoelectric bimorph actuators in micro-positioning application

Piezo driver for piezoelectric bimorph actuators is the key component for micro-positioning application. Hysteresis nonlinearity of piezoelectric bimorph actuators limits the performance of micro-positioning systems. A novel piezo driver was developed with Prandtl-Ishlinskii (P-I) model and correction network. The combination of P-I model and correction network can describe the rate-dependent hysteresis. Experiments were performed to validate the proposed piezo driver. The results show that the piezo driver can compensate the hysteresis of the piezoelectric bimorph actuator in the frequency range of 0.1 Hz to 10 Hz, and the accuracy of micro-positioning have been greatly improved.