8 Some Perspectives on MEMS-Based Active Control

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NATO Advanced Study Institute RESPONSIVE SYSTEMS … / MEMS Course Brussels, September 10-19, 2001

Laboratoire de Mécanique Appliquée – UMR CNRS 6604 – Université de Franche Comté Institut des Microtechniques de Franche Comté

8 Some Perspectives on MEMS-Based Active Control

Micromachines 2000 In cooperation

with EPFL

Packaging and Integration Mechanical Modeling

and Optimization Parallel

Manipulators Programmable

Vector Fields CMOS Integrated Micromanipulators

Microactuator Arrays

Active acoustical Impedance

Active Microsuspensions Flapping Wing Propulsion Systems Autonomous Micro Air Vehicles MEMS-based

Smart Structures

On-chip Characterization of Silicon-based Materials

Tests Microlabs

Mechanical Characterization of Biological Cells 2001

2002

2003

2004

MEMS Technology

(in cooperation with EPFL)

High Density Hard Drives

M a ch in in g (n m )

De n si ty ( cm

-2

)

Year IC Transistor Density Bit Density

(Magnetic Recording)

From web site: www.storage.ibm.com

MEMS-Based Active Control of Read / Write Magnetic Head

Specifications:

- Disk Rotation Speed: 7800 rpm - Angular Partitioning: 52 sectors - Radial Partitioning: 0.4µm/step - Magnetic Head Altitude: 15 nanometers - Positioning Precision: 50 nanometers - Lifetime: 10 years Market Perspectives:

- 2 B US S

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Tiny Hard Drives

From web site: www.storage.ibm.com

Toward MEMS-Based Control of Acoustical Impedance

Objective: Kill the Source of Noise due to Mechanical Vibrations by Using Distributed Acoustic Transducers

Experimental Setup

Doc. LMARC

106 dB (distance : 1m)

Cross Section of an Elementary Acoustic Transducer

Acoustic Radiation of the Uncontrolled Wafer Acting as a Membrane

δ

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MEMS-Based Acoustic Transducer Array

Doc. LMARC / web site: www.micromachines.univ-fcomte.fr

Design of an Elementary Acoustic Transducer

Localisation des électrodes Raidisseurs : 4µm

l1/2 l2

l3

l4

l7

l5

l6

l8

l9

X

Y

Geometrical Parameters

l

1

= 20µm ; l

2

= 470µm ; l

3

= 460µm ; l

4

= 460µm ; l

5

= 5µm ; l

6

= 10µm ; l

7

= 160µm ; l

8

= 30µm ; l

9

= 10µm.

Acoustic Transducer Thickness : ep

1

= 2µm Mechanical Stiffener : ep

2

= 4µm

Transducer/Substrate Gap: g

1

= 7µm Driving Electrode: S = l

7

× l

7

Doc. LMARC

Acoustic Transducers using Electrostatic Actuation: Out-of-Plane Motion Analysis

Doc. LMARC / web site: www.micromachines.univ-fcomte.fr

nitrure

nitrure nitrure in air

pull

g ep

ε ε δ ε

3 +

1

−

=

( )

[ ]

S l

ep El ep

V g

nitrure air

air nitrure nitrure

2 32

13 1 2 1

2 16 ε

ε

δ ε ε

δ +

= +

V V

µm _pull _in

in

pull ₋ = 2 . 36 ; ₋ = 22

δ

Quasi-Static Control of Out-of-Plane Motion (Up to 9800 Hz)

Toward MEMS-Based Active Control of Turbulence

From web site: www.ensimag.fr

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8 Some Perspectives on MEMS-Based Active Control