Multi-physics modeling of Micro- Electro-Mechanical

Multi-physics modeling of Micro-Electro-Mechanical-Systems using

EMS for SOLIDWORKS

by

EMWorks Inc.

1

Majdi Elfahem

Senior Application Engineer

Agenda

• Overview about MEMS applications

• Challenges versus solutions

• Examples

• Conclusion

2

MEMS- Micro-Electro-Mechanical-Systems

3https://ieeexplore.ieee.org/document/6575798

https://www.arrow.com/en/research-and-events/articles/mems-and-iot-applications

https://ieeexplore.ieee.org/document/296932

MEMS Applications: Challenges versus solutions

Challenges Solutions

4

Geometrical modeling

Materials modeling

Ohmic losses, electric and magnetic forces

Capacitance, inductance, resistance, etc

Multi-physics

Isotropic, anistropic, temperature dependent,etc

Electric and magnetic modules (static, harmonic

and transient)

Thermal and structural coupling

SOLIDWORKS

Design iterationsParameterization (geometrical and simulation variables )/ SW multi-

configurations

EMS for SOLIDWORKS

Example 1- Comb drive actuator

5Optimizing the Performance of MEMS Electrostatic Comb Drive Actuator with Different Flexure Springs.Shefali Gupta , Tanu Pahwa , Rakesh Narwal , B.Prasad , Dinesh Kumar


6

MaterialsSection

Electromagnetic inputs: Voltage, charge, floating conductors/ force definition

Structural inputs: constraints, loads, connectors…

EMS mesher

Results: Electric and structural results folders

EMS modules Multiphysicscoupled analyses of EMS

EMS Tree

7


Voltage Results Electric Field Results

8


Mechanical Displacement Results Von Mises Stress Results

9

0.00E+00

5.00E+05

1.00E+06

1.50E+06

2.00E+06

2.50E+06

3.00E+06

3.50E+06

4.00E+06

0 20 40 60 80 100 120 140

Vo

n M

ise

s St

ress

(N

/m^2

)

Voltage (V)

Von Mises Stress Results versus Voltage

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 20 40 60 80 100 120 140

Dis

pla

cem

ent

(um

)

Voltage (V)

Mechanical Displacement versus Voltage


10


Fixed-fixed beam Crab leg flexure beam Folded flexure beam

11



12



13

0.00E+00

5.00E+05

1.00E+06

1.50E+06

2.00E+06

2.50E+06

3.00E+06

3.50E+06

4.00E+06

0 20 40 60 80 100 120 140

Vo

n M

ise

s St

ress

(N

/m^2

)

Voltage (V)

Von Mises Stress Results for Different Configurations

Fixed fixed beam Folded flexure beam Crab lef flexure beam


0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 20 40 60 80 100 120 140

Dis

pla

cem

en

t (u

m)

Voltage (V)

Displacement Results for Different Configurations

Fixed fixed beam Crab leg flexure beam Folded flexure beam

14

0

100

200

300

400

500

600

700

0 20 40 60 80 100 120 140

Elec

tro

stat

ic F

orc

e (

nN

)

Voltage (V)

Electrostatic Force Results versus Voltage

0.61

0.615

0.62

0.625

0.63

0.635

0.64

0.645

0.65

0.655

0 0.5 1 1.5 2

Cap

acit

ance

(p

F)

Displacement (um)

Capacitance Results versus Displacement


Example 2- Micro-thermal actuator (Joule heating)

15

Properties Values

Relative permittivity (𝜀𝑟) 4.5

Electrical conductivity (𝜎) 45000 S/m

Young modulus (𝛦) 160*10^9 Pa

Poisson ration (𝜈) 0.22

Mass density 2320 kg/m^3

Thermal expansion 2.6e-6 (1/K)

Thermal conductivity 34 (W/m*K)

Specific heat 678 (J/Kg*K)

Silicon Properties


16

Electromagnetic inputs

Thermal inputs

Structural inputs

Results: Electric, thermal and structural

Thermal loads: temperature and convection

Mechanical constraints

17


Current Density ResultsVoltage Results

18

0

100

200

300

400

500

600

700

0 0.0005 0.001 0.0015 0.002

Tem

per

atu

re (

C)

Time (s)

Temperature Variation versus Time


0

100

200

300

400

500

600

700

0 0.01 0.02 0.03

Tem

pe

ratu

re (

C)

Distance (mm)

Temperature Variation Across the Actuator

0

100

200

300

400

500

600

700

0 0.05 0.1 0.15 0.2

Tem

per

atu

re (

C)

Distance (mm)

Temperature Variation Along the Hottest Arm

Temperature Results

19

0

0.5

1

1.5

2

2.5

3

0

10000000

20000000

30000000

40000000

50000000

60000000

70000000

80000000

0 0.0005 0.001 0.0015 0.002 0.0025

Dis

pla

cem

ent

(um

)

Vo

n M

ise

s St

ress

(N

/m^2

)

Time (s)

Von Mises Stress and Displacement Results

Von Mises Stress Displacement

Example 2- Micro- thermal actuator (Joule heating)

Von Mises Stress Results

Mechanical Displacement Results

20

0.00E+00

2.00E+07

4.00E+07

6.00E+07

8.00E+07

1.00E+08

1.20E+08

1.40E+08

0

0.5

1

1.5

2

2.5

3

3.5

0 1 2 3 4 5 6

Voltage (V)

Vo

n M

ise

s St

ress

(N

/m^2

)

Dis

pla

cem

ent

(um

)

Displacement and Von Mises Stress Results versus Applied Voltage

Displacement Von Mises Sress

0

100

200

300

400

500

600

700

800

0 1 2 3 4 5 6

Tem

pe

ratu

re (

C)

Voltage (V)

Temperature Results versus Applied Voltage


21

0.00E+00

1.00E-06

2.00E-06

3.00E-06

4.00E-06

5.00E-06

200 400 600 800 1000 1200Ther

mal

exp

ansi

on

(1

/K)

Temperature (K)

Thermal Expansion

0

5

10

15

20

25

30

35

40

0 200 400 600 800 1000

J/kg

*K

Temperature (C)

Thermal Conductivity

0

20000

40000

60000

200 400 600 800 1000 1200

Sigm

a (S

/m)

Temperature (K)

Electrical Conductivity

0

0.2

0.4

0.6

0.8

1

1.2

0 500 1000 1500 2000 2500

Spe

cifi

c h

eat

(J/

g*K

)

Temperature (C)

Specific Heat


22

0

0.5

1

1.5

2

2.5

3

0

100

200

300

400

500

600

700

800

0 0.0005 0.001 0.0015 0.002 0.0025 0.003 0.0035

Dis

pla

cem

ent

(um

)

Tem

per

atu

re (

C)

Axis Title

Temperature and Displacement Results

Temperature Results Displacement Results

Max temp. Max disp. Max stress

Constant properties 635 2.32 2e+8

Temperature dependent properties

700 2.48 2.15e+8

Error (%) 10% 6.8% 6.9%


Mechanical Displacement Results

23

Cold arm

Hot arm


24

0

5

10

15

20

25

855

860

865

870

875

880

885

890

2 3 4 5

Dis

pla

cem

ent

(um

)

Tem

per

atu

re (

C)

Hot arm thickness (um)

Temperature and Displacement versus Hot Arm Thickness

Temperature Displacement

10

12

14

16

18

20

22

500

550

600

650

700

750

800

850

900

20 25 30 35 40

Cold arm thickness (um)

Temperature and Displacement versus Cold Arm Thickness


0

5

10

15

20

25

500

550

600

650

700

750

800

850

900

5 7 9 11 13 15

Axi

s Ti

tle

Spacing (um)

Temperature and Displacement versus Spacing Between Arms



25

Example 3- Valveless micro-pump

https://www.emworks.com/application/ems-structural-simulation-of-valveless-micro-pump-based-on-electromagnetic-actuation

a) Picture of the fabricated micro-pump, b) and its schematic illustration

a) 3D isometric view of the micropump b) cross-sectional view of the micro- pump.

26

Example 3- Valveless micro-pump

Chang, Hsien-Tsung, et al. "Theoretical analysis and optimization of electromagnetic actuation in a valveless microimpedance pump." Microelectronics journal 38.6-7 (2007): 791-799.

Force Results versus Current Displacement Results Deflection versus Magnetic Force (0.9A)

27

Conclusion

o EMS was used to study different MEMS devices including electric and magnetic applications

o Electrostatic and magnetic forces were computed by EMS

o Ohmic losses and capacitance results were calculated by EMS

o Temperature variation and structural deformation were estimated versus different situations and

scenarios

o EMS results were compared to experimental and analytical results

Documents

Multi-physics modeling of Micro- Electro-Mechanical