Microscanner

A microscanner, or micro scanning mirror, is a microoptoelectromechanical system (MOEMS) in the category of micromirror actuators for dynamic light modulation.

Depending upon the type of microscanner, the modulatory movement of a single mirror can be either translatory or rotational, on one or two axes.

For these applications, actuation using a Lissajous pattern can accomplish sinusoidal scan motion, or double resonant operation.

Nevertheless, the highly non-linear drive characteristics in some parts of the deflection area can be hindering for controlling the mirror properly.

For that reason many highly developed microscanners today utilize a resonant mode of operation, where an eigenmode is activated.

For beam positioning and applications which are to be static-actuated or linearized-scanned, quasi-static drives are required and therefore of great interest.

Magnetic actuators offer very good linearity of the tilt angle versus the applied signal amplitude, both in static and dynamic operation.

Also thermal actuators are not suitable for high frequency operation due to significant low pass behaviour.

Piezoelectric drives produce high force, but as with electrothermal actuators the stroke length is short.

This has proven to be difficult for quasi-static scanners, although there are promising approaches in the literature using long meandering flexures for deflection amplification.

[17] Microscanners are resistant to environmental influences, and can tolerate humidity, dust, physical shocks in some models up to 2500g, and can operate in temperatures from -20 °C to +80 °C.

With current manufacturing technology microscanners can suffer from high costs and long lead times to delivery.