AlN based piezoelectric micromirror

Abstract

Aiming to pursue a micromirror possessing many desired characteristics, such as linear control, low power consumption, fast response, and easy fabrication, a new piezoelectric actuation strategy is presented. Different from conventional piezoelectric actuation cases, we first propose using AlN film as the active layer for actuating the micromirror. Owing to its good CMOS compatible deposition and patterning techniques, the AlN based piezoelectric micromirror has been successfully fabricated with a modified silicon-on-insulator-based microelectromechanical system (MEMS) process. At the same time, various mirror movement modes operating at high frequencies and excellent linear relationship between the movement and the control signal both have been experimentally demonstrated.

Modeling and Optimization of a Novel ScAlN-Based MEMS Scanning Mirror with Large Static and Dynamic Two-Axis Tilting Angles

“…Therefore, the gravity effect of the mirrors during the analysis can be ignored to simplify theoretical calculations and simulations. Table 4 compares the static performance of Devices A and B presented in this paper with other piezoelectric scanning mirrors reported in the literature [ 11 , 21 , 42 , 43 , 44 ]. It is demonstrated that the proposed devices tend to exhibit an outstanding θ · D product.…”

“…Although each actuation method above can exhibit some unique characteristics for certain applications, some common challenges confronted largely prevent the achievement of both large 2-degrees-of-freedom (2-DoF) tilting angles and static non-resonant operation. In comparison, numerous impressive piezoelectric actuation micromirrors reported in the previous literature have demonstrated the achievement of resonant/static actuation mode, linear control, fast response and low power consumption characteristics [ 4 , 11 , 16 , 21 , 22 , 23 , 24 ]. A piezoelectric micromirror is less affected by air damping, thermal or electromagnetic interference than those driven by the electrostatic, thermal or electromagnetic force.…”

“…Chen et al presents a MEMS thin-PZT cantilever driven micro-lens actuator capable of delivering a large out-of-plane displacement of 145 μm at 22 V driving voltage, with a resonant frequency of 2 kHz [ 16 ]. Although commonly used PZT-type micromirrors exhibit large deflection due to high piezoelectric coefficients, the high permittivity resulting in low energy conversion efficiency, large temperature coefficient, low Curie point, hysteresis behavior, challengeable patterning process and poor compatibility with the mainstream complementary metal-oxide-semiconductor (CMOS) and/or MEMS process greatly limits its wide use in the MEMS area [ 4 , 20 , 21 , 22 , 23 , 24 ].…”

“…The AlN-based piezoelectric actuation strategy for a micromirror application has been presented and fabricated firstly by Shao et al, with a modified silicon-on-insulator-based MEMS process, demonstrating full CMOS compatibility, excellent linear control and various mirror movement modes [ 21 ]. However, both dynamic and static mirror operation modes of this device have the tilting angles of only about 0.2°/V and 0.005°/V, respectively, which is attributed to low piezoelectric coefficients of AlN material.…”

IPMC Kirigami: A Distributed Actuation Concept

“…In terms of electroactive materials, several authors have reported actuating micromirrors using piezoceramics, e.g. PZT [18] and aluminium nitride [19]. Also preliminary efforts have been made in cutting of the soft IPMC materials to obtain pumps [17], and several authors have studied etching of the IPMC samples to separate sensing and actuation regions [20], [21].…”