The need for precision positioning applications has enormously influenced the research and development towards the growth of precision actuators. Over the years, piezoelectric actuators have significantly satisfied the requirement of precision positioning to a greater extent with the capability of broad working stroke, high-accuracy, and resolution (micro/nano range) coupled with the advantage of faster response, higher stiffness, and actuation force. The present review intends to bring out the latest advancement in the field of piezoelectric actuator technology. This review brings out the specifics associated with the development of materials/actuators, the working principles with different actuation modes, and classifications of the piezoelectric actuators and their applications. The present article throws light on the design, geometrical features, and the performance parameters of various piezoelectric actuators right from unimorph, bimorph, and multilayer to the large displacement range actuators such as amplified actuators, stepping actuators with relevant schematic representations and the quantitative data. A comparative study has been presented to evaluate the pros and cons of different piezoelectric actuators along with quantitative graphical comparisons. An attempt is also made to highlight the application domains, commercial and future prospects of technology development towards piezoelectric actuators for precision motion applications. The organization of the paper also assists in understanding the piezoelectric materials applicable to precision actuators. Furthermore, this paper is of great assistance for determining the appropriate design, application domains and future directions of piezoelectric actuator technology.

Piezoelectric actuators find extensive application in delivering precision motion in the micrometer to nanometer range. The advantages of a broader range of motion, rapid response, higher stiffness, and large actuation force from piezoelectric actuators make them suitable for precision positioning applications. However, the inherent nonlinearity in the piezoelectric actuators under dynamic working conditions severely affects the accuracy of the generated motion. The nonlinearity in the piezoelectric actuators arises from hysteresis, creep, and vibration, which affect the performance of the piezoelectric actuator. Thus, there is a need for appropriate modeling and control approaches for piezoelectric actuators, which can model the nonlinearity phenomenon and provide adequate compensation to achieve higher motion accuracy. The present review covers different methods adopted for overcoming the nonlinearity issues in piezoelectric actuators. This review highlights the charge-based and voltage-based control methods that drive the piezoelectric actuators. The survey also includes different modeling approaches for the creep and hysteresis phenomenon of the piezoelectric actuators. In addition, the present review also highlights different control strategies and their applications in various types of piezoelectric actuators. An attempt is also made to compare the piezoelectric actuator’s different modeling and control approaches and highlight prospects.

In recent years, microfluidic devices, particularly micropumps, are extensively utilized in biomedical applications. The micropump used in biomedical applications needs to possess precise delivery of fluids at requires rate and pressure. The present work proposes a valveless mechanical micropump with a disposable chamber integrated with a novel concept of annular excitation of the diaphragm to fulfil the need for precise delivery of fluids in biomedical applications. The proposed design of the micropump involves a reusable configuration of the amplified piezoelectric actuator (APA) for micropump actuation and a disposable pump chamber. The pumping of the fluids occurs through the oscillation of the silicone rubber bossed diaphragm. The performance of a mechanical micropump depends on the oscillation amplitude of the diaphragm. Thus, the conventional approach of central excitation of the bossed diaphragm is replaced by a novel approach of annular excitation intended to enhance the deflection range, thus the volumetric performance of the micropump. An experimental comparative study is carried out to assess the deflection characteristics of central excitation and annular excitation of the bossed diaphragm. The maximum deflection measured with the annularly excited configuration of the bossed diaphragm is about 1953.4 ± 8.00 µ m at 150 V, 43.5 Hz, which is superior to the maximum deflection of centrally excited configuration delivering 717.99 ± 4.00 µ m at 150 V, 9.5 Hz. Further, the experimental studies aimed to fabricate and characterize the micropump with central and annular excitation approaches. The proposed micropump with central excitation delivered the maximum water flow rate of about 7.192 ± 0.147 ml min ⁻¹ and backpressure of 0.294 kPa at 150 V, 5 Hz. However, the enhancement of the deflection characteristics of the bossed diaphragm under annular excitation leads to performance enhancement of the micropump with the flow rate of 95.10 ± 0.444 ml min ⁻¹ and backpressure of 1.472 kPa at 150, 30 Hz