Resonant PZT MEMS Scanner for High-Resolution Displays

Abstract

Abstract-A resonant piezoelectric scanner is developed for high-resolution laser-scanning displays. A novel actuation scheme combines the principle of mechanical amplification with lead zirconate titanate (PZT) thin-film actuation. Sinusoidal actuation with 24 V at the mechanical resonance frequency of 40 kHz provides an optical scan angle of 38.5• for the 1.4-mm-wide mirror. This scanner is a significant step toward achieving full-highdefinition resolution (1920 × 1080 pixels) in mobile laser projectors without the use of vacuum packaging. The reported piezoscanner requires no bulky components and consumes < 30-mW power at maximum deflection, thus providing significant power and size advantages, compared with reported electromagnetic and electrostatic scanners. Interferometry measurements show that the dynamic deformation is at acceptable levels for a large fraction of the mirror and can be improved further for diffraction-limited performance at full resolution. A design variation with a segmented electrode pair illustrated that reliable angle sensing can be achieved with PZT for closed-loop control of the scanner.[ 2012-0116]Index Terms-High-frequency laser beam scanning, lead zirconate titanate (PZT) thin-film-actuated, microelectromechanical systems (MEMS), MEMS mirror, resonant scanner.

An electrostatically driven 2D micro-scanning mirror with capacitive sensing for projection display

“…Contrary to the DLP technology in which majority of the tasks for image production are realized optically, electronic design plays a more important role for scanning-type projectors. As demonstrated in prior studies, micro-scanning mirrors may be driven by electrostatic [5][6][7][8][9][10][11][12][13][14], electromagnetic [15][16][17][18] or piezoelectric [19][20][21][22][23] mechanisms. Each approach has its own advantages and disadvantages.…”

“…Few studies have demonstrated micro-scanning mirrors with on-chip capacitive [12][13], piezoresistive [14] and piezoelectric [21] sensing capabilities. Drabe et al [14] reported a bi-axial electrostatic scanning mirror with piezoresistive sensors.…”

“…Adding another electrically independent set of sensing electrodes would complicate the structural design and require more manufacturing steps [12]. The other plausible sensing schemes using piezoresistive [14] and piezoelectric [21] materials also face similar challenges in parasitic feedthrough and limited routing paths that would necessitate more manufacturing steps. The main objective of the present study is to demonstrate simultaneous capacitive driving and position sensing with the same comb-drive electrodes for a 2D Lissajous scanning mirror.…”

High-uniformity centimeter-wide Si etching method for MEMS devices with large opening elements

“…The scanner used in a previous research for actuation was 3.75 × 6.15 mm 2 , to actuate a 1.4 mm inner mirror frame. 13) Therefore, to realize a higher quality MEMS mirror, the die size of the actuator must reach the centimeter order.…”

Large Tilt Angle Lorentz Force Actuated Micro-Mirror with 3 DOF for Optical Applications

“…It is connected to the outer frame through flexures. The outer frame is 90° rotated with respect to the inner frame and can tilt about its longitudinal axis which is perpendicular to the inner frame tilting axis [9][10][11][12]. These types of structures are usually of larger size compared to gimbal-less structures, and consume larger power in operation.…”