PolyMUMPS

George KweiMirela Cunjalo

Gary Lu

Overview

PolyMUMPS Technology Description

Our Designs, ideas and problems First-Half Second-Half

Questions

PolyMumps

Technology Processes Designed to be as General as Possible

3 polysilicon layers + 1 metal layerOxide – sacrificial layerHoles – removes PolysiliconAnchors – removes OxideDimples

First-Half [Stepper Motor]

Stepper Motor using Heatuators What are

Heatuators?

First-Half [Stepper Motor]

SolidWorks – Heatuator Array

First-Half [Stepper Motor]

Problem with existing design Placement of pads No dimples Remove staple More Heatuators required

First-Half [Stepper Motor]

New Adjustments

First-Half [Stepper Motor]

SolidWorks – Stepper Motor Animations

First-Half [Stepper Motor]

Variations in New Designs

Second-Half [Initial Design]

Switch via a Gear Train … Too ambitious!

Second-Half [Alternating Switch]

Simplifications

Second-Half [Alternating Switch]

SolidWorks – Alternating Switch Animation

Second-Half [Regulated Motor]

Basic Idea

Second-Half [Regulated Motor]

Problems to consider

High Tension of SpringNeed more HeatuatorsNeed longer Spring

Spacing of Teeth

Length of the bar

Second-Half [Regulated Motor]

Calculations: Spring/Tension

Compliance : C = L3 / (E * I) * (N/12 + 1/48)

L - length of the barsE - Young’s ModulusN - # of barsI - 2nd moment of the bars

Moment:

I = 1/12 * w * h3 w - width of the barsh - thickness.

Second-Half [Regulated Motor]

Calculations: Number of Heatuators

F = k * x * µx - distance the spring is stretchedK - spring constant (C-1) µ - coefficient of static friction between polySilicon and polySilicon (4.9 ± 1.0)

d = do*N + C / N * F

d - deflectiondo – no-load deflection for one heatuator

N - number of heatuatorsF - opposing force

Second-Half [Regulated Motor]

Solutions – variation 1 Pull-Ring

Second-Half [Regulated Motor]

Solutions – variation 2 Longer Spring

(Pull-Ring)

Second-Half [Regulated Motor]

SolidWorks – Pullring Animation

Second-Half [Regulated Motor]

Solutions – variation 3 Linear Stepper-Motor

Ratchet Motor

Ratchet Motor

Calculations: Flexture

a1

a2

d1d2

1

2

1

2

a

a

d

d

Ratchet Motor

SolidWorks – Animation

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

Questions?

PolyMUMPS

Mirela CunjaloGeorge Kwei

Gary Lu