Laser Graphic Video Display using Silicon Scanning Mirrors with Vertical Comb Fingers

Large Angle Silicon-on-Insulator Tilting Actuator with Kinematic Excitation and Simple Integrated Parallel-Plate Electrostatic Transducer

“…Most of the reported large angle tilting actuators are actuated either by vertical comb-drive transducers 14) or incorporate amplification mechanisms, 20,21) which often require intricate fabrication process and complicated operation. Other kinematically excited micro-mirrors that were reported in the literature, 17,18) used piezoelectric actuation.…”

“…The tilting element is typically suspended using elastic torsional axis while actuating forces or moments are applied directly to the tilting element. [13][14][15] Though large variety of actuation methods are used in MEMS, including thermal, 12) magnetic, 16) and piezoelectric 17) actuation, the electrostatic actuation remains the most widely used due to its high efficiency at the micro scale and compatibility with common MEMS fabrication processes. [1][2][3][4][5][13][14][15] Generally, in electrostatic tilting actuators the electrostatic torque is applied using either close gap capacitive transducer, 1,3,13,15,18) where the tilting element serves as a moveable capacitor and a stationary electrode is placed beneath it, or vertical comb drive actuator, incorporating fingers attached to the tilting element.…”

“…[13][14][15] Though large variety of actuation methods are used in MEMS, including thermal, 12) magnetic, 16) and piezoelectric 17) actuation, the electrostatic actuation remains the most widely used due to its high efficiency at the micro scale and compatibility with common MEMS fabrication processes. [1][2][3][4][5][13][14][15] Generally, in electrostatic tilting actuators the electrostatic torque is applied using either close gap capacitive transducer, 1,3,13,15,18) where the tilting element serves as a moveable capacitor and a stationary electrode is placed beneath it, or vertical comb drive actuator, incorporating fingers attached to the tilting element. 14) Close gap actuators benefit from simple architecture, but demonstrate small angles, limited by the electrostatic gap that is required in order to apply sufficiently large electrostatic force.…”

“…[1][2][3][4][5][13][14][15] Generally, in electrostatic tilting actuators the electrostatic torque is applied using either close gap capacitive transducer, 1,3,13,15,18) where the tilting element serves as a moveable capacitor and a stationary electrode is placed beneath it, or vertical comb drive actuator, incorporating fingers attached to the tilting element. 14) Close gap actuators benefit from simple architecture, but demonstrate small angles, limited by the electrostatic gap that is required in order to apply sufficiently large electrostatic force. Vertical comb drives, on the other hand, permit achievement of large tilting angles, but suffer from intricate fabrication process, which often involves critically timed etching and/or bonding and fabrication of large quantities of small, critical size, elements.…”

Electrostatic 1D microscanner with vertical combs for HD resolution display

“…In case of laser projection display, the technical requirements are large tilting angle, high driving frequency and large mirror size to obtain a high resolution image with low power consumption. To meet these requirements, we have been developing the scanning micro mirror having vertical comb fingers [14][15][16][17][18][19][20][21].…”