Optical MEMS at ARI (MOEMS)

     
 
             
 

Video demonstrations of Two-axis (2D) MEMS Micromirrors / Optical Scanners

 

Prototype/demonstration 2D scanner devices are now available for purchase

 

New video (12/2006): Large Micromirrors - Latest actuators from ARIMEMS7 generation of devices provide bi-directional two-axis scanning. Largest mirrors to date in the 2mm diameter and the 3mm diameter range are mounted on the actuators and demonstrated (6.4 MB)

To date, most generations of ARIMEMS micromirror devices provide uni-directional scanning in two-axes, e.g. from 0° to 8° on each axis. In other words, mirror scans a laser beam only in one quadrant of the hemisphere above the chip. Most recent generation of devices includes two types of actuators shown in this video that allow bi-directional scanning, e.g. -5° to 5° of mechanical tip/tilt.

Latest generation of ultra-lightweight micromirrors fabrication allows the use of large micromirrors in the 2mm diameter range ("Biggies,") and in the 3mm range ("Jumbos,") at relatively high scanning speeds. Video shows very slow speed scanning driven by MirrorcleDraw software to demonstrate the large mirrors under stereo microscope.

 

MirrorcleDraw Demo 1 - Vector Graphics Display Demo - drawing various patterns, text (16 MB)

We have developed a PC-based LaserDraw software, to control and drive ARI's gimal-less two-axis micromirrors. The software allows the user to create drawings, various mathematical curves, Lissajous patterns. The drawings and patterns to be drawn by the micromirror are pre-filtered by user-chosen filter type and bandwidth to prevent micromirror oscillations and ringing.

Our driver software is now capable of processing and displaying Intl. Laser Display Association (ILDA) - compatible files which include various drawings and animations that can be found in the web-based public domain.

MirrorcleDraw - ILDA file animations (17 MB)

MirrorcleDraw - Vector Graphics Demo 3 (4.1 MB)

 

Recent video (04/2006): TrackingDemo1 - Using video acquisition, system tracks the position of a red laser spot and directs a green laser beam to that spot with ARI's two-axis MEMS scanning micromirror (7.5 MB)

We have also developed a PC-based MirrorcleTrack software, to control and drive ARI's gimbal-less two-axis micromirrors in connection with a video acquisition capability. The software firstly allows the user to acquire a 2-dimensional look-up table for the MEMS device, accurately mapping desired position on the display (wall) to required actuation voltages. This is done by monitoring the laser spot on the display with a video camera in a closed-loop acquisition mode. After the table of required voltages and positions is known, the device can be accurately directed to target a red laser spot that is seen inside of its display area.

Video also show the capability of the algorithm to ignore false-positive targets, whether they are spots of wrong color (another green laser,) or spots of wrong size (small red spot,) and to remain locked onto the primary target (large red spot.)

 

Recent video (04/2006): Transparent Display Demo - Turning a transparent glass window into a vector graphics display (6.9 MB)

Using MirrorcleDraw software to create vector graphics patterns, text, and displaying ILDA animations, the video demonstrates displaying on a transparent glass surface which is coated with a special film.

 

Recent video (4/06): 2x2 Tip-Tilt-Piston Array - Array of gimbal-less devices (5.6 MB)

Recent video (6/06): 2x2 Tip-Tilt-Piston Array - Individual Element Control (14.8 MB)

Recent video (5/06): 2x2 Tip-Tilt-Piston Array - Individual Control - Stereo Microscope View (5.6 MB)

 
 

Recent video (04/2006): Various Micromirror Sizes (6.0 MB)

ARI devices can be assembled with ultra-light micromirrors of various sizes. Such, special size micromirrors are metal-coated and are available in sizes with 0.8mm, 1.2mm, 1.6mm, and 2.0mm diameter. Standard silicon micromirrors are integrated with the actuator and have a diameter of 0.7mm.

 

Scanning demonstration with LaserDraw software: Step responses: (12 MB)

This video demonstrates step responses and open-loop settling time of ARI's gimbal-less two-axis scanner. The driver software, LaserDraw provides step inputs and variety of possible filters. The fastest response, with <200 us settling time are obtained by 'inverse system square root' filter. The demonstration corresponds to the work published recently in:

V. Milanović, K. Castelino, Sub-100 µs Settling Time and Low Voltage Operation for Gimbal-less Two-Axis Scanners," , IEEE/LEOS Optical MEMS 2004, Takamatsu, Japan, Aug. 2004.

 

Archival video: Dynamic scanning demonstration: Video 1 (17 MB) Video 2 (22 MB) These videos demonstrate low-voltage driving of a 2D Scanners at its mechanical resonant frequencies of 6 kHz for both axes; the scanner is driven from a notebook's audio port, through transformers for voltage amplification. Left channel contains x-axis data and the right channel contains the y-axis data.

 

Archival video: Vector drawing video 1(18 MB) Archival video: Vector drawing video 2 (13.5 MB)

These videos demonstrates low-voltage driving of the 2D Scanners such that it is possible to drive a scanner from a notebook's audio port (~1 V). Therefore, we are able to stream desired control signals to the 2D scanner from various Matlab functions, where the left audio channel contains x-axis data and the right channel contains the y-axis data. The streams represent co-ordinates of various graphics from the computer screen which are laser-drawn onto the wall at high refresh rates. Such complex drawings at >30 Hz refresh rates are possible due to the very high speed of the gimbal-less devices in both axes.

The demo also shows the effect of volume and balance change on the notebook's audio. Refresh rate of the scanner in this video is >30 Hz, but the display looks flashy in the video due to the mismatch of rates with the camera and due to mpg compression of frames. Those projected laser-drawn images in reality look very still to a human eye.

 
                 

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