MEMS%20for%20Adaptive%20Optics

1
MEMS for Adaptive Optics
Adaptable-Mirror Section
Array of Elevating Mirrors
Mirror Substrate
Scale mm to cm
Current-Driver Electronics
Solder-Bump Electrical Connections
2
How Can We Elevate the Mirror Elements?

• Magnetic Actuation
• Solenoidal structures
• Electrostatic Actuation
• Vertical comb-drives
• Thermal Actuation
• Thermal-bimorph structures
• Our initial design approach

3
Berkeley Bimorph Process

• Single-mask process
• Low-stress nitride (SixNy) and aluminum bimorph
• Other processes under consideration
• Hidden actuators
• Electrostatic actuators
• Bonded mirrors

Current path
Mirror

• Mirror

Die photo - actuated, released mirrors
4
Conclusions

• Bimorph actuator is small and can be fabricated
  under the mirror
• Fill factor gt 98
• Bimorph actuators can be tiled in an arrays to
  actuate large numbers of mirrors
• Bimorph actuator provides large tip deflection (h
  10 mm)
• Models show frequency requirements are met (fgt1
  kHz)
• Bimorph actuators have been fabricated
• Testing is underway