PolyMUMPS

1. PolyMUMPS George Kwei Mirela Cunjalo Gary Lu

2. Overview • PolyMUMPS Technology Description • Our Designs, ideas and problems • First-Half • Second-Half • Questions

3. PolyMumps • Technology Processes Designed to be as General as Possible • 3 polysilicon layers + 1 metal layer • Oxide – sacrificial layer • Holes – removes Polysilicon • Anchors – removes Oxide • Dimples

4. First-Half [Stepper Motor] • Stepper Motor using Heatuators • What are Heatuators?

5. First-Half [Stepper Motor] • SolidWorks – Heatuator Array

6. First-Half [Stepper Motor] • Problem with existing design • Placement of pads • No dimples • Remove staple • More Heatuators required

7. First-Half [Stepper Motor] • New Adjustments

8. First-Half [Stepper Motor] • SolidWorks – Stepper Motor Animations

11. First-Half [Stepper Motor] • Variations in New Designs

12. Second-Half [Initial Design] • Switch via a Gear Train … Too ambitious!

13. Second-Half [Alternating Switch] • Simplifications

14. Second-Half [Alternating Switch] • SolidWorks – Alternating Switch Animation

16. Second-Half [Regulated Motor] • Basic Idea

17. Second-Half [Regulated Motor] Problems to consider • High Tension of Spring • Need more Heatuators • Need longer Spring • Spacing of Teeth • Length of the bar

18. Second-Half [Regulated Motor] • Calculations: • Spring/Tension Compliance : C = L3 / (E * I) * (N/12 + 1/48) L - length of the bars E - Young’s Modulus N - # of bars I - 2nd moment of the bars Moment: I = 1/12 * w * h3 w - width of the bars h - thickness.

19. Second-Half [Regulated Motor] • Calculations: • Number of Heatuators F = k * x * µ x - distance the spring is stretched K - spring constant (C-1) µ - coefficient of static friction between polySilicon and polySilicon (4.9 ± 1.0) d = do*N + C / N * F d - deflection do – no-load deflection for one heatuator N - number of heatuators F - opposing force

20. Second-Half [Regulated Motor] • Solutions – variation 1 • Pull-Ring

21. Second-Half [Regulated Motor] • Solutions – variation 2 • Longer Spring (Pull-Ring)

22. Second-Half [Regulated Motor] • SolidWorks – Pullring Animation

26. Second-Half [Regulated Motor] • Solutions – variation 3 • Linear Stepper-Motor

27. Ratchet Motor

28. a2 a1 d1 d2 Ratchet Motor • Calculations: • Flexture

29. Ratchet Motor • SolidWorks – Animation

31. Conclusion • What we learned: • use lots of instances for Cadence • make sure snap to grid is at 1.0 micron • make sure all geometries are uniform numbers • carefully go over design rules first, minimum distances, etc. • Fix all the errors on one design before proceeding to the next • Discuss designs with TAs before making them in Cadence • Designs should correspond to at least 3x the calculations, to make sure everything will work

32. Questions? PolyMUMPS Mirela Cunjalo George Kwei Gary Lu