The Anti-Gravity MicroMachine

What are Micromirrors?

• Change the angle of a reflected beam in multiplexing and de-multiplexing of optical signals

• Very precise and flawless• Aim: raise the mirror to the desired

angle

Mirror Animation

The Problem

• Vertical lift cannot be obtained through horizontal movement

• Fabrication process leads the mirror to sag down

Fixed Hinge

MirrorLever Applied

Force

Wafer

The Solution

• Provide initial lift to the mirror

Fixed Hinge Mirror Lever Applied

Force

Wafer

Thermal Actuators

• Make use of differing arm thickness to provide movement

• Problem: using the principles described, it is difficult to obtain vertical movement

Vertical Thermal Actuators

• Design 1: Built to provide a downward motion but is overdriven; when current is removed the actuator snaps up

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More Vertical Thermal Actuators • Design 2: Provides upward motion

through the use of thin flexible connectors

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Even More Vertical Thermal Actuators• Design 3: U-shaped designed to

prevent thicker arm from conforming

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Thermal Actuator Animation

Levers

• Design 4: Downward Vertical Thermal Actuator is used to create lift by pressing down on one end of a lever

Mirror Hinge Thermal Actuator

Lever

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More Levers

• Design 5: Flexible connector used to transfer downward force of Vertical Thermal Actuator to a lever

Mirror Hinge Thermal Actuator

Lever

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Lever Animation

Linear Stepper Motor

• Makes use of 2 banks of horizontal thermal actuators to provide a drive mechanism

Staple HingeRotating Bar

Staple

Staple Hinge

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Staple Hinge Issues

Rotating bar

Rotating bar

Applied Force

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Torsion Hinge

• Thin flexible rods attached to mirror on either side

Mirror

Rotating Bar

Lever

Applied Force

Prevent Bar from Bowing Out

Torsion Hinge

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Final Picture

Possible Issues

• Torsion hinge might break or not be flexible enough

• Actuating arms might bend• Vertical thermal actuators might not give

enough deflection

Conclusion

• Testing has yet to be done• “We are confident of positive results…”

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