basic 5 micro-actuator - electrostatic ...gcoe.mech.nagoya-u.ac.jp/basic/pdf/basic-05.pdf · cell...

Basic 5Micro actuatorMicro-actuator

- Electrostatic actuator -Electrostatic actuator

Associate Prof. M. ShikidaAssociate Prof. M. ShikidaDept. of Micro/Nano Systems Engineering

N U i itNagoya University

Basic 5 Micro-actuator - Electrostatic actuator - Associate Prof. M. ShikidaCOE for Education and Research of Micro-Nano Mechatronics, Nagoya University

Micro-actuatorElectrostatic force Magnetic force

Rotational typeRotational type

Diaphragm type

Rotational type

Cantilever type

Cantilever typeLinear drive type

Comb drive type

Stacked film type


Micro-actuatorThermal force Piezoelectric force

Bi-metal(Diaphragm type)

Pneumatic typeDiaphragm type Cantilever type

Pneumatic type

Bi-metal(Cantilever type)

SMA typeSMA type

Thermal expansion type


Micro-actuator

Comparison of various force applied in Micro-actuator

Force Response Power consumption Integration

Electrostatic force ＋＋＋＋＋＋＋＋＋＋

Magnetic force ＋＋＋＋＋＋＋＋Magnetic force ＋＋＋＋＋＋＋＋

Thermal force ＋＋＋＋＋＋＋

Piezo electric force (Stack type) ＋＋＋＋＋＋＋＋Piezo electric force (Stack type) ＋＋＋＋＋＋＋＋

Piezo electric force (Film type) ＋＋＋＋＋＋＋＋＋＋


Electrostatic actuator

Th h l t t ti f i li d iThe reason why electrostatic force is applied in micro-sized actuator

Scale effectSimple structureCompatible with MEMS fabrication processCompatible with MEMS fabrication processIntegration with IC and micro-sensor


Generative force

Comparison between electrostatic and magnetic forces(Force per unit area)(Force per unit area)

2EU ,

22

EUE

Di l t i t t E El t i l fi ld,2

2HUM

: Dielectric constant, E: Electrical field: Permeability, H: Magnetic field

TB

mVE1

/103 6

21 /10 mNU

TB 1

25 /10

/10

mNU

mNU

M

E


Generative force

Scale effect

EUE2

: Dielectric constant, E: Electrical fieldEUE ,

2

e ec c co s a , ec ca e d

SkEFE ,2

　　　

k: Constant, S: Surface areaSkEFE ,2

　　　　　　　

　　　

constELFE :@2　　　


Generative force

Scale effect

,2HUM

: Permeability, H: Magnetic field　,2

HUM e eab y, ag e c e d

　～32LFM M

(In the case of permanent magnet)

　～43LFM M(In the case of electric magnet)


Electrostatic force

Electrostatic energy gy

,21

21

21 2

2

CVCQQVUE C: Capacitance, Q: Charge,

V: Potential222 C V: Potential

Electrostatic force U

constQ

Ex x

UF

In the case of Q=constant

Ex

UF

In the case of V=constantEnergy is supplied by electrical power

constVx x Energy is supplied by electrical power

source


Electrostatic force

Parallel plate type y

Normal forcey

gyNormal forcey

x

y

0

z

l0

x0

by

gLateral force

0 l g

xl0

x


l

Electrostatic forceNormal component force

lbC

22 lbyy

C

y

22

22Force

VylbQ

lbyUE

z

b

.][ constQForce

x

0b

l2

2 lbQ

yUF

constQ

Ey

　　y

2

.][

lbVU

constVconstQ

gy

2

2

2ylbV

yUF

constV

Ey

　　x

l0


Force is inverse square function of distance

Electrostatic force

bl

Lateral component force

blg

bxlC

y

22

22V

gbxlQ

bxlgUE

z

b

.][ constQForce

x

0b

l

2

22Q

bxlg

xUF

constQ

Ex

　　y .][

bUconstV

constQ

g

2

2V

gb

xUF

constV

Ex

　　x

l0x


Force does not depend on distance

Electrostatic force

Comb-drive actuatorL t l tLateral movement

Fixed electrodeMovable electrode

yy

gg

g21 yF

FxF

xl0

2

xyF

l


Electrostatic force

Comb-drive actuator L t l t

4 bxlC

Lateral movement

Fixed electrode

22 bxlhg

C

　　Fixed electrodeMovable electrode

y 2

2

2

bU

Vhg

bxlUE

y

g22 V

hgb

xUF

constV

Ex

g

21 yF

FxF

xl0

xyF

h: thickness of electrode

・Electrostatic force is independent of distance.・It is proportional of number of electrodes.

l


It is proportional of number of electrodes.

Electrostatic force

Comb-drive actuator _ Vertical movement type 22

22, V

gY

zUFV

gYZU

gYZC

constV

EzE

，　　

Rotational type 21 VCT 2

1 2VT

Rotational type (Wobble motor)Rotational type (Wobble motor) i rRnVCT 02

2 ,1

iRnV

nT2 ,

2

Torsion bar type

2log21,log2

1

Vhh

hbUhh

hbCdxxbC E

x

x

　


Electrostatic force

Pull-in phenomenon

2lbyElectrostatic force

kF 2

22V

ylbygkyF

y

gSpring force

eFy

ygkyF

Spring force

xl

0 Pull-in voltage

kgV 28 21

3

0 Pull in voltage

gylb

gV inpullinpull 3,

27

　


Comb-drive-actuatorCell handling based on comb drive actuator

H Hid t l T h Di f IEEE MEMS 2009 912 915


H. Hida, et al., Tech. Dig. of IEEE MEMS, 2009, 912-915.

S-shaped film actuator


S-shaped film actuatorCharacteristics in air


M. Shikida., T. IEE Japan, 116-E, 1996, 395-401

S-shaped film actuatorCharacteristics in liquid

M Shikida T IEE Japan 117 E 1997 227 231



S-shaped film actuatorGas valve application



Tulip-shaped actuator for haptic display

Haptic displayOperation principle

Haptic display

DisplayClutch produced by micro-actuatorClutch produced by micro actuatorStepping motor


H. Sasaki, et al., J. Micromech. Microeng., 16, 2006, 2673-2683.

Tulip-shaped actuator for haptic displayTulip-shaped actuator for clutch



Tulip-shaped actuator for haptic display

xxs 2)()(

Tulip-shaped actuator for clutch _ analysis

xLxLcxxwL

xs

222 )46()(

)()(

L

el dxgxwxsd

hVU0

0

20

)()(21

L

b

r

dxdx

xwdEIU

g

0

2

2

2

0

)(21

)()(

LdxwdEI

dx

22

])([1

2

Lelb

dxd

dxdx

EI

hEIVUUU 0

22

0

)()(

1

])([20

r

gxwxs00)()(



Tulip-shaped actuator for haptic displayTulip-shaped actuator for clutch _ analysis



Tulip-shaped actuator for haptic displayTulip-shaped actuator for clutch _ fabrication



Tulip-shaped actuator for haptic displayTulip-shaped actuator for clutch _ operation



Tulip-shaped actuator for haptic displayAssembled haptic display

Di l t 20 60Displacement：20-60 mGenerative force: 600 mNSize: 30 mm x 30 mm x 40 mm



Tulip-shaped actuator for haptic displayDemonstration of haptic display


Summary

O i f Mi t tOverview of Micro-actuatorElectrostatic forceGenerative forceComb-drive actuatorPull-in phenomenon

S-shaped film actuator for gas valve applicationS shaped film actuator for gas valve applicationTulip-shaped actuator for haptic display


basic 5 micro-actuator - electrostatic ...gcoe.mech.nagoya-u.ac.jp/basic/pdf/basic-05.pdf · cell...

Documents