Eos Actuator Jmems2005 1

8/12/2019 Eos Actuator Jmems2005 1

1/10

548 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 14, NO. 3, JUNE 2005

A Single-Layer PDMS-on-Silicon HybridMicroactuator With Multi-Axis Out-of-Plane Motion

CapabilitiesPart I: Design and AnalysisYi-Chung Tung, Student Member, IEEE,and Katsuo Kurabayashi, Member, IEEE

AbstractThis paper proposes a new single-layer electrostaticmicroactuator design that generates three-axis motion resultingin vertical translation and out-of-plane tilting. The new actuatordesign combines a micrometer-scale three-dimensional (3-D)polydimethylsiloxane (PDMS) structure fabricated using softlithography with comb drives processed using a single mask on asilicon-on-insulator (SOI) wafer. The multi-axis actuation capa-bility of the proposed actuator is enabled by coupling the in-planeactuation motion of the comb drives with the elastic bending of

PDMS flexural microjoints. To predict the static and dynamic per-formance of the actuator, this paper develops a four-bar-linkagemodel and applies Lagrangian dynamics theory. The developedanalytical model is validated using finite element analysis (FEA)and allows us to perform parametric design of the actuator. Theanalysis indicates that the proposed PDMS-on-silicon hybridactuator can yield the desired multi-axis actuation capability witha dynamic bandwidth as large as 5 kHz. [1378]

Index TermsComb-drive actuator, finite element analysis(FEA), multi-axis microactuator, parametric design, PDMS-on-sil-icon microsystems.

I. INTRODUCTION

MICROMETER-SCALE actuation with multiple degreesof freedom plays an essential role in many micro-

electromechanical systems (MEMS) applications, including

microrobotics [1], micromanipulation [2], [3], and microop-

tics systems [4][10]. Significant research efforts have been

made to develop electrostatic MEMS actuators capable of

multi-axis in-plane/out-of-plane motions [3], [4], [9][12].

However, the fabrication of these actuators is often challenging

and time-consuming, requiring multilayer structures [4], [6]

or relatively complex mechanisms [12]. Furthermore, their

assembly requires precise alignment and bonding of multiple

silicon substrates, adding more complexity to the laborious

fabrication processes.Comb-drive actuators are commonly adapted in electrostatic

MEMS actuation devices as they can be fabricated using

CMOS-compatible standard silicon surface micromachining

and yield a large dynamic bandwidth [13]. The comb-drive

structure simply consists of interdigitated electrodes of a

Manuscript received July 8, 2004; revised August 27, 2004. This work wassupported by the National Science Foundation CAREER Award. Subject EditorC. Hierold.

The authors are with the Department of Mechanical Engineering, Univer-sity of Michigan, Ann Arbor, MI 48109 USA (e-mail: [email protected];[email protected]).

Digital Object Identifier 10.1109/JMEMS.2005.844761

rectangular finger shape that are engaged with each other and

mechanically compliant spring beams that suspend one of

the electrodes. Electrostatic force resulting from bias voltage

between the engaging electrodes drives their lateral motion.

Despite their common use in MEMS technology, the short-

coming of comb drives is that they predominately generate

one-dimensional (1-D) motion, which usually lies parallel to

the substrate plane [10], [11], [13][15]. This leads to the need

for the aforementioned complex fabrication processes.For example, Kwon et al. [6] have recently presented an

asymmetric comb drive on a silicon-on-insulator (SOI) wafer.

It was fabricated by a three-step back and front side deep

reactive ion etch (DRIE) process, and it achieved out-of-plane

piston motion. Using both surface [Multiuser MEMS Processes

(MUMPS)] and bulk micromachining (DRIE), Piyawat-

tanamethaet al.[16] developed an angular vertical comb drive

to generate out-of-plane tilting motion with one degree of

freedom. Moreover, they integrated two sets of the actuators

to generate out-of-plane tilting motion in two orthogonal axes.

Xie et al. [17] also exploited curled hinges, which resulted

from residual stress between different materials, to constructa similar vertically angled offset comb drive that yields tilting

motion. Walraven and Jokiel [12] constructed a spatial mi-

crostage that yields three degree-of-freedom motion [either

XYZ translation or piston-tip-tilt (PTT)] using the Sandia Ul-

traplanar MEMS Multilevel Technology (SUMMiT-V) silicon

surface micromachining process. With the same process, Hah

et al.[18] developed a comb-drive actuated micromirror array

that generates single degree-of-freedom motion (out-of-plane

tilting).

This paper proposes a novel polymer/silicon hybrid actuator

that allows multi-axis, out-of-plane vertical and tilting actuation

motions, only requiring a single silicon layer with comb drives.

The actuator design incorporates a 3-D polydimethylsiloxane

(PDMS) microstructure placed on a silicon device layer. With

this new actuator design, we theoretically demonstrate how the

integration of a 3-D PDMS microstructure can allow us to de-

velop a new type of MEMS actuator. The performance of the

actuator can be substantially enhanced by the flexibility of the

polymer. This paper focuses on the design and analysis of the

proposed PDMS-on-Silicon hybrid microactuator.

II. HYBRIDACTUATORDESIGN

Fig. 1 illustrates the actuator proposed in this paper. The

actuator is designed to translate the in-plane 1-D motion of

1057-7157/$20.00 2005 IEEE

Authorized licensed use limited to: University of Michigan Library. Downloaded on November 12, 2009 at 23:42 from IEEE Xplore. Restrictions apply.


2/10

TUNG AND KURABAYASHI: A SINGLE-LAYER PDMS-ON-SILICON HYBRID MICROACTUATORPART I 549

Fig. 1. Schematic drawing of the PDMS-on-silicon hybrid actuator.

comb drives to the out-of-plane motion of a PDMS microstruc-

ture with multiple degrees of freedom. The actuator structure

consists of two major components: (1) multiple comb drives

fabricated on a SOI wafer; and (2) a PDMS micromotion trans-

lator connected to the comb drives. The PDMS micromotion

translator is composed of a micrometer-scale platform and four

connectors. Each of the PDMS microconnectors provides a

mechanical connection between the platform and a comb-drive

rotor beam via two thinflexural microjoints.

We assume that the PDMS micromotion translator is fab-ricated using soft lithography here [19]. PDMS is an organic

elastomer material widely used in a number of BioMEMS and

microfluidic applications [20][23] due to its excellent optical

properties ( 92% transmission for visible light [24]) and large

maximum strain limit near 40% [25], [26] (for silicon material,

it is 1%.) With its high optical transparency and mechanical

robustness, the PDMS micromotion translator can be an excel-

lent structural component in optical MEMS applications.

Fig. 2 shows the details of the PDMS micro-connector with

its end attached to a comb drive rotor beam. This connector

plays a primary role in converting the in-plane motion of the

comb drive to the out-of-plane motion of the mechanically rigidPDMS microplatform. The PDMS microconnector attached to

the electrically controllable comb drives is designed to achieve

precise nanopositioning and displacement multiplication. Sys-

tematically coupling the motion of each comb drive allows the

actuator to switch its modes in a programmable manner. For in-

stance, simultaneously pulling the PDMS-silicon connections

by activating either all of the four comb drives (#1 to #4) or two

of them facing each other (e.g., comb drives #1 and #3 or #2

and #4) would cause vertical motion of the PDMS microplat-

form in Fig. 3(a). On the other hand, the PDMS microplatform

will generate out-of-plane tilting motion with only two orthog-

onal comb drives activated (#1 and #4). In addition, the opposite

tilting motion with respect to the same axis can be achieved bycombining the motions of another pair of comb drives (#2 and

Fig. 2. Simplified four-bar linkage model of the PDMS microconnectorattached to a comb-drive actuator rotor.

#3), which doubles the tilting angle range for each axis as shown

in Fig. 3(b). Similarly, the tilting around the other axis can be

achieved using other combinations of moving comb drives [e.g.,comb drives #1 and #2; #3 and #4 as shown in Fig. 3(c)].



3/10


Fig. 3. Actuation modes resulting in (a) vertical motion, (b) tilting motion 1,and (c) tilting motion 2 of the hybrid actuator.

III. HYBRIDACTUATORMODELING ANDFEA VALIDATION

In this section, we develop an analytical model based on a

four-bar-linkage mechanism to theoretically study the actuatorperformance and compare calculations using this model to nu-

merical results from finite element analysis (FEA). The devel-

oped analytical model allows for subsequent parametric design

with less computational time and expense than FEA.

A. Modeling of Hybrid Actuator

We model each of the four PDMS microconnectors as a

four-bar linkage with two rotational springs as shown in Fig. 2.

Each of the two flexural microjoints has thickness and

length , which are smaller than the other dimensions of the

micromotion translator. This design leads to the deformation of

theseflexural microjoints caused by bending motion about the-axis. As a result, we treat each of them as a pin joint located

at its middle position with a rotational spring constant . A

rigid-body boundary condition is applied for both ends of the

flexural microjoint as they are connected to either a stiff silicon

comb-drive rotor beam or a thicker PDMS layer.

Now, we use simple beam theory to evaluate the rotational

spring constant of theflexural microjoints. When subjected to

a bending moment , the microjoint attached to a rigid body

yields a slope at its end, given by

(1)

where is the Youngs Modulus of the beam material

(PDMS), and is the moment of inertia of the beam representing

the microjoint. Thus

(2)

Furthermore, the geometrical relations of the equivalent

four-bar linkage are given by

(3a)

(3b)

(3c)

(3d)

where and are the initial lengths of the linkage in the

- and -directions, respectively, is the initial length of thelinkage, and is the initial angle of the linkage, is the length

of theflexural microjoint, is the length of the microconnector,

is the thickness of the flexural microjoint, and is the thick-

ness of the microconnector. When the microconnector rotates by

an angle , the mathematical expressions for the input in-plane

displacement of the comb drive and the output vertical dis-

placement of the PDMS platform are given by

(4a)

(4b)

where and are the positions of the comb drive and the

PDMS microplatform in the coordinate system shown in Fig. 2.

Equations (4a) and (4b) allow us to evaluate how much the input

displacement is multiplied through its translation to the ver-

tical output displacement . Here, we define a displacement

multiplication ratio as , which can be given by

(5)

For a small rotational angle (i.e., ), the multiplication

ratio can be simplified as

(6)

which can provide us an approximate value of multiplicationratio for selected device design parameters in the simple



4/10


Fig. 4. FEA simulation results. (a) Vertical displacement of the PDMS micromotion translator. (b) von Mises stress distribution in the PDMS micromotiontranslator.



5/10


TABLE IMATERIALPROPERTIES USED FORANALYSIS

analyticalform. With aninput force applied tothe PDMS

microconnector from the comb drive, the resulting rotational

angle against the two rotational springs in series is given

by

(7)

From (7), the vertical position of the PDMS microplatform is

also the function of . By knowing the rotational angle of the

microconnector for a given applied force , the dis-

placements of the PDMS micromotion translator in the hori-zontal and vertical directions and can be calculated

from (4).Since the relationbetween and isnonlinear,

the analysis requires iterative calculations.

B. Model Validation Using FEA

To validate the developed four-bar linkage model, we per-

formed FEA using the commercial software ANSYS Release

7.0 (ANSYS Inc., PA.) The symmetry of the PDMS micromo-

tion translator allows us to analyze its mechanical behavior by

simply taking the quarter part, as shown in Fig. 4. In the simu-

lation, we used the 3-D brick element SOLID45, each node of

which has three degrees of freedom. Also, a nonlinear finite el-ement simulation option was employed to account for large de-

formations of the structure. There are two boundary conditions

we utilized to validate the developed model: (a) the displace-

ment boundary condition, where a given displacement input is

applied to the end of the PDMS flexural linkage; and (b) the

force boundary condition, where the displacement input in (a)

is replaced with a given force input.

Table I shows the material properties used for both of the

four-bar linkage model and the FEA simulation. The results of

the FEA are shown in Fig. 4. The simulation indicates that the

thin joints of the PDMS microconnector yield much larger de-

formation than the thicker platform part. This allows us to safelyassume that the PDMS microplatform is a perfectly rigid body in

the model. In addition, local stresses are mainly concentrated in

the thin joints of the microconnector, which proves that they can

act as flexural joints during the actuator operation as assumed

in the analytical model. Fig. 5 compares the results obtained

from the analytical calculation and the FEA simulation under

(a) the displacement and (b) the force boundary conditions. It is

shown that the calculation based on the four-bar linkage model

is in a good agreement with the FEA simulation with an error

less than 5% at input displacement up to 5 . Fig. 5(c) shows

the simulated displacement multiplication ratio for the

input displacement up to 5 . Both analytical calculation and

FEA simulation yield the multiplication ratio approximate 2 forthe selected device design parameters. The slight increase of

the multiplication ratio indicates the minor nonlinearity of the

PDMS micromotion translator performance. The results prove

that the PDMS micromotion translator not only translates the

in-plane displacement to the out-of-plane direction but also am-

plifies the magnitude of the input displacement from the comb

drive. The analytical model is shown to predict the device per-

formance reasonably well for typical comb-drive actuation in-puts.

IV. STATIC ANDDYNAMIC PERFORMANCEANALYSIS

We use a simplified parallel-plate capacitor model [14] topre-

dict the actuation behavior of the comb drives. Combing the

four-bar linkage model with the parallel plate capacitor model

allows us to model the performance of the entire hybrid actuator.

In this paper, the whole device structure is modeled as a dis-

crete mass-spring system subjected to external load as shown in

Fig. 6. This model allows us to predict the relationship between

the in-plane electrostatic actuation force of the comb drive and

the vertical displacement of the PDMS microplatform. Here, theexternal load generated by each comb drive is given by

(8)

where is the gap between the adjacent combfingers, is the

thickness of the combfingers, is the total number of the comb

fingers, is the voltage applied across the engaging comb elec-

trodes, and is the vacuum permittivity. There are two spring

constant sources in the model: (1) one from the folded beams of

the comb drive, whose spring constant is assumed to be invariant

with the rotor deflection; and (2) another from the elasticity

of the PDMS flexural microjoints, which has a spring constant

varying with the deflection. The spring constant of the folded

suspension beam of the comb drive is given by [14]

(9)

where is Youngs Modulus of silicon, is the thickness of

the silicon structure, and and are the width and length of

the suspension beams, respectively. By calculating the displace-

ment of the rotor (i.e., the in-plane displacement input to

the PDMS microconnector), the vertical output displacement of

the PDMS microplatform is calculated for a given input

voltage .

Fig. 7 shows the calculated static performance of the actu-

ator with the dimensions shown in Table II. Fig. 7(a) shows the

actuation force generated by each comb drive as a function of

given by (8). Fig. 7(b) shows the calculated and as

functions of when two facing comb drives are activated. Fol-

lowing the same approach, the tilting angle of the PDMS mi-

croplatform generated by two orthogonally activated comb

drives can be calculated by

(10)

where is the distance between the two parallel lines connecting

a pair of orthogonal comb drives as shown in Fig. 3(b). Thecalculated as a function of is shown in Fig. 7(c).



6/10


Fig. 5. Comparisonof four-bar linkageanalysisand FEAsimulation of thePDMS micromotion translator performance using (a)displacementboundary condition,and (b) force boundary condition. (c) Displacement multiplication ratio calculated from (a) and (b).

Fig. 6. Discrete mass-spring system model for the entire device structure.

To study the dynamic performance of the hybrid actuator, we

have applied Lagranges equations to the developed analytical

model. The Lagrangian is defined as

(11)

where and are kinetic energy and potential energy, respec-

tively. By definition, and of the designed system can begiven by

(12a)

(12b)

Thus, the Lagrangian can be written as

(13)

where is the mass of the comb drive rotor, is the

mass of the PDMS microplatform, is the spring constant

of the silicon suspension beam, and is the rotational

spring constant of the PDMS flexural microjoint. The spring

constant of the foldedsuspension beamof the comb drive is

given by (9), andthe rotational spring constant of PDMS flexural

microjoint is equal to given by (2). Therefore, theLagranges equation of motion of the system can be written in

the form

(14)

Substituting , and given by (13), (8), and (4a) yields

an expression for each term of (14) as

(15a)

(15b)

(15c)

(15d)



7/10


Fig. 7. Theoretical static performance of the hybrid actuator as a function of applied actuation voltage. (a) Electrostatic force generated at each comb drive.(b) In-plane displacement of comb-drive rotor

1

and vertical displacement of the PDMS microplatform1

. (c) Tilting angle of the PDMS micro-platform1

.

TABLE IINOMINALVALUES OF THE ACTUATOR DESIGNPARAMETERSUSED FOR

THEORETICALANALYSIS

The equations derived above shows the nonlinearity of the

system, which would be complex to analyze. For simplicity, the

first-order linearization is applied by assuming

(16)

Then each term in the equation of motion can be simplified as

(17a)

(17b)

(17c)

Consequently, the resulting equation of motion for the system

without damping can be expressed as

(18)

Moreover, the viscous damping term is added to the equation

of motion for evaluating the performance of the damped system

as

(19)

where is the rotational damping coefficient. For a sinusoidal

voltage excitation at an angular frequency , the applied voltage

can be written as

(20)

where is the dc offset voltage. Fig. 8 shows the calculated

time-domain vertical velocity and displacement of the hybrid

actuator with two facing comb drives activated at 1 kHz when

. The calculation assumes a low damping system

with the damping ratio , where can be calculated by

(21) shown at the bottom of the next page.

Fig. 8(c) shows little distortion in the displacement profile

with respect to the sinusoidal actuation signal, indicating a goodlinearity of the actuation motion. Fig. 9 shows the calculated



8/10


Fig. 8. Predicted time-domain dynamic performance of the actuator using the developed model. (a) Input actuation voltage signal. (b) Vertical velocity of thePDMS microplatform. (c) Vertical displacement of the PDMS microplatform.

Fig. 9. Calculated amplitude spectrum of vertical displacement of the hybrid

actuator.

vertical displacement spectrum of the hybrid actuator at actua-

tion frequencies between 500 Hz and 10 kHz with various values

of the damping ratio. All the calculations presented here have

been performed with the device dimensions shown in Table II.

The calculation predicts that the resonant frequency of the actu-

ator is about 4.86 kHz.

V. PARAMETRICANALYSIS

The actuator capable of multi-axis out-of-plane motion may

find broad applications. The performance requirement is dif-

ferent depending on each application. For example, fast out-of-

plane actuation capability with wide bandwidth ( 1 kHz) is re-

quired for a confocal scanning microscope to observe biolog-

ical phenomena occurring on the microsecond timescale [27].

For dense wavelength-division-multiplexed (DWDM) compo-

nents, actuation of a mirror with a large static scan angle (e.g.,

at 40 V) is needed [28]. To observe how the proposed ac-

tuator can be designed to fulfill the different requirements, we

study the sensitivity of its performance with respect to the de-

vice design parameters using the developed model. Since the

output vertical displacement and natural frequency of actu-

ators are most commonly specified for various applications [7],

[16], [28][29], we choose them as the performance evaluation

parameters in our analysis.

Wefirst took the values of the design parameters in Table II

as nominal ones in our parametric analysis, which yield a nat-ural frequency about 5 kHz and an vertical displacement of ap-

proximately 5 at a 40 V peak-to-peak voltage applied on

each of two facing comb drives. Then we varied each of the de-

sign parameters from 0.6 to 1.4 times its nominal value. The

calculated results are shown in Fig. 10 and Fig. 11 and indi-

cate that the static vertical displacement and the natural fre-

quency are most sensitive tothe length and width of the

(21)



9/10


Fig. 10. Predicted variation of static vertical displacement of the hybrid

actuator with design parameters.

Fig. 11. Predicted variation of natural frequency of the hybrid actuator with

design parameters.

comb-drive suspension beam. In general, there exists a tradeoff

between and the natural frequency with the varying param-

eters. For instance, increases with an increasing value ofwhile the natural frequency becomes smaller at the same time.

This tradeoff results from the reciprocal relationship between

the displacement and the natural frequency for a given mechan-

ical stiffness of the entire system. The actuator design process

needs to account for this tradeoff. However, it is not observed

for and . The decrease of the spacing between the combfin-

gers increases the actuation force at constant applied voltage,

and decreases the mass of the structure at the same time. This

leads to a simultaneous increase of both and the natural fre-

quency. Similarly, the decrease offlexural microjoint thickness

leads to the same result due to the decrease of both of the

structural stiffness and mass. The minimum values of these pa-

rameters would be mainly limited by the fabrication capability.By carefully choosing the device dimensions according to the

analysis, the microactuator can be designed to yield a fast re-

sponse and large out-of-plane displacement at a relatively small

actuation voltage.

VI. CONCLUSION

This paper has proposed a new electrostatic actuator incor-porating a 3-D PDMS microstructure that can achieve multi-

axis out-of-plane motion driven by simple single-layer silicon

comb drives. A mechanical model of the PDMS structure using

a four-bar linkage analogy was developed and validated by FEA

simulation. Combing this four-bar linkage model and a par-

allel-plate capacitor model for the comb drives, the static and

dynamic performances of the entire actuator were evaluated.

Parametric analysis of the static vertical displacement and nat-

ural frequency of the proposed actuator were also conducted to

study the influence of design parameters on them. The micro

actuator with dimensions that we select is expected to yield a

vertical motion of nearly 5 and an out-of-plane tilting mo-

tion of 1.2 at a 40-V dc actuation voltage, and a resonant fre-quency of about 5 kHz. All the analytical models developed in

this work effectively serve for predicting the actuator perfor-

mance in the parametric analysis. With its estimated fast dy-

namic response and multi-axis motion capability with relatively

large displacement, the proposed PDMS-on-silicon hybrid ac-

tuator is promising for various MEMS applications requiring

on-chip actuation functions.

This paper demonstrates the technological potential of

combining the polymer material (PDMS) and silicon MEMS

devices. The unique material properties of the polymer can

increase the functionality of various MEMS devices with a

simple structural design. Theflexibility of the polymer wouldhelp a MEMS actuator generate large displacement at a limited

actuation force. Its mechanical robustness would increase the

device reliability. In addition, the polymer material can be used

for optical components such as optical lenses [30] and gratings

[31] due to its optical transparency, and can help achieve

reconfigurable microoptical devices embedded with electron-

ically controllable silicon-based actuators. Consequently, the

presented results promote the development of a wide variety of

novel polymer/silicon hybrid MEMS devices.

REFERENCES

[1] S. Hollar, A. Flynn, C. Bellew, and K. S. J. Pister, Solar powered 10 mgsilicon robot,in Proc. 16th Annual Int. Conf. Microelectromech. Syst.,Kyoto, Japan, 2003.

[2] K.-F. Bhringer, B. R. Donald, and N. C. MacDonald, Single-crystalsilicon actuator arraysfor micromanipulation tasks, in Proc. 9thAnnual

Int. Workshop on Microelectromech. Syst., San Diego, CA, 1996.[3] H. Kanayama, T. Tsuruzawa, N. Mitsumoto, T. Idogaki, and T. Hat-

tori,Micromanipulator utilizing a bending and expanding motion actu-ator,in Proc. 10th Annual Int. Workshop on Microeelectromech. Syst.,Nagoya, Japan, 1997.

[4] J. C. Chiou and Y.-C. Lin,Micromirror device with tilt and piston mo-tions, in Proc. Design, Characterization, and Packaging for MEMS and

Microelectron., Gold Coast, Australia, 1999.[5] P. F. V. Kessel, L. J. Hornbeck, R. E. Meier, and M. R. Douglass,A

MEMS-based projection display, in Proc. 11th Annual Int. Conf. Mi-croelectromech. Syst., 1998.

[6] S. Kwon, V. Milanovic, and L. P. Lee, Vertical microlens scanner for3D imaging, in Proc. Solid-State Sens. ActuatorWorkshop, HiltonHeadIsland, SC, 2002.



10/10


[7] S.Kwonand L. P. Lee, Micromachined transmissive scanning confocalmicroscope,Opt. Lett., vol. 29, pp. 706708, 2004.

[8] A. Tuantranont and V. M. Bright,Segmented silicon-micromachinedmicroelectromechanical deformable mirrors for adaptive optics,J. Se-lect. Topics in Quantum Electron., vol. 8, pp. 3345, 2002.

[9] J.I. Young and A.M. Shkel, Comparative study of 2-DOFmicromirrorsfor precision light manipulation,in Proc. Smart Structures and Mate-rials 2001: Smart Electron. MEMS, Newport Beach, CA, 2001.

[10] C.-H. Kim and Y.-K. Kim, Integration of a microlens on a microXY-stage, in Proc. Device and Process Technologies for MEMS andMicroelectron., Gold Coast, Australia, 1999.

[11] Y. Sun, D. Piyabongkarn, A. Sezen, B. J. Nelson, and R. Rajamani,A high-aspect-ratio two-axis electrostatic microactuator with extendedtravel range,Sens. Actuators A: Phys., vol. 102, pp. 4960, 2002.

[12] J. A. Walraven and B. Jokiel, Failure analysis of a multi-degree-of-freedom spatial microstage,in Proc. Reliability, Testing, and Charac-terization of MEMS/MOEMS II, San Jose, CA, 2003.

[13] C. Chen, C. Lee, Y.-J. Lai, and W. Chen,Development and applicationof lateral comb-drive actuator, Japan. J. Appl. Phys., Part 1: RegularPapers and Short Notes and Review Papers, vol. 42, pp. 40594062,2003.

[14] R. Legtenberg, A. W. Groeneveld, and M. Elwenspoek,Comb-driveactuators for large displacements, J. Micromechan. Microeng., vol. 6,pp. 320329, 1996.

[15] J. D. Grade, H. Jerman, and T. W. Kenny, Design of large deflection

electrostatic actuators,J. Microelectromech. Syst., vol.12, pp. 335343,2003.

[16] W. Piyawattanametha, P. R. Patterson, D. Hah, H. Toshiyoshi, and M. C.Wu,A 2D scanner by surface and bulk micromachined angular verticalcomb actuator,in Proc. IEEE/LEOS Int. Conf. Opt. MEMS, 2003.

[17] H. Xie, Y. Pan, and G. K. Fedder,A CMOS-MEMS with curled-hingecomb drives,J. Microelectromech. Syst., vol. 12, pp. 450457, 2003.

[18] D. Hah, S. T.-Y. Huang, J.-C. Tsai, H. Toshiyoshi, and M. C. Wu,Low-voltage, large scan angle MEMS analog micromirror arrays with hiddenvertical comb-drive actuators, J. Microelectromech. Syst., vol. 13, pp.279289, 2004.

[19] Y. Xia and G. M. Whitesides,Soft lithography,Ann. Rev. Mater. Sci.,vol. 28, pp. 153184, 1998.

[20] C. S. Effenhauser, G. J. M. Bruin, A. Paulus, and M. Ehart,Integratedcapillary electrophoresis on flexible silicone microdevices: analysis ofDNA restriction fragments and detection of single DNA molecules onmicrochips,Analyt. Chem., vol. 69, pp. 34513457, 1997.

[21] B.-H. Jo, L. M. Van Lerberghe, K. M. Motsegood, and D. J. Beebe,

Three-dimensional micro-channel fabrication in polydimethylsiloxane(PDMS) elastomer,J. Microelectromech. Syst., vol. 9, pp. 7681, 2000.

[22] Y.-C. Tung, M. Zhang, C.-T. Lin, K. Kurabayashi, and S. J. Skerlos,

PDMS-based opto-fluidic microflow cytometer with two-color, multi-angle fluorescence detection capability using PIN photodiodes, Sens.

Actuators B: Chem., vol. 98, pp. 356367, 2004.[23] D. Huh, Y.-C. Tung, H.-H. Wei, J. B. Grotberg, S. J. Skerlos, K.

Kurabayashi, and S. Takayama, Use of air-liquid two-phase flow inhydrophobic microfluidic channels for disposable flow cytometers,

Biomed. Microdev., vol. 4, pp. 141149, 2002.[24] S. J. Clarson and J. A. Semlyen,Siloxane Polymer. Englewood Cliffs,

NJ: Prentice-Hall, 1993.[25] J. C. Ltters, W. Olthuis, P. H. Veltink, and P. Bergveld, Polydimethyl-

siloxane as an elastic material applied in a capacitive accelerometer,J.Micromechan. Microeng., vol. 6, pp. 5254, 1996.

[26] , The mechanical properties of the rubber elastic polymer poly-dimethylsiloxane for sensor applications,J. Micromech. Microeng., vol.7, pp. 145147, 1997.

[27] S. Katagiri,T. Takamatsu,T. Minamikawa, andS. Fujita, Secretagogue-induced calcium wave shows higher and prolonged transients of nuclearcalcium concentration in mast cells,FEBS Lett., vol. 334, pp. 343346,1993.

[28] W. Piyawattanametha, P. R. Patterson, D. Hah, H. Toshiyoshi, and M. C.Wu,A surface and bulk micromachined angular vertical combdrive forscanning micromirrors,in Conf. Opt. Fiber Commun., 2003.

[29] H. Oku and M. Ishikawa,A variable-focus lens with 1 kHz bandwidth

applied to axial-scan of a confocal scanning microscope,in Proc. 16thAnnual Meeting of the IEEE Lasers & Electro-Optics Society (LEOS),Tucson, AZ, 2003.

[30] K. Wang, K.-S. Wei, M. Sinclair, and K. F. Bhringer, Micro-opticalcomponents for a MEMS integrated display (invited paper), in Proc.12th Int. Workshop on The Physics of Semiconductor Devices (IWPSD),Chennai, India, 2003.

[31] K. Hosokawa, K. Hanada, and R. Maeda, A polydimethylsiloxane(PDMS) deformable diffraction grating for monitoring of local pressurein microfluidic devices, J. Micromechan. Microeng., vol. 12, p. 1,2002.

Yi-Chung Tung (S02) received the B.S. and M.S.degrees in mechanical engineering from the National

Taiwan University, Taiwan, in 1996 and 1998,respectively. His Masters degree research is fo-cused on piezoelectric actuator design, piezoelectricMEMS device analysis, and fabrication.

He is currently a Ph.D. degree candidate in me-chanical engineering at the University of Michigan,Ann Arbor. His Ph.D. studies include polymer andsilicon hybrid MEMS devices design and fabrication,as well as their applications in microoptics and bio-

logical detection.

Katsuo Kurabayashi (M98) received the B.S.degree in 1992 in precision machinery engineeringfrom the University of Tokyo, Japan, and theM.S. and Ph.D. degrees in materials science andengineering with an electrical engineering minorfrom Stanford University, CA, in 1994 and 1998,respectively. His dissertation work focused onmeasurement and modeling of the thermal transportproperties of electronic packaging and organic ma-terials for integrated circuits under the contract with

the Semiconductor Research Corporation (SRC).Upon completion of the Ph.D. program, he joined the Department of Me-

chanical Engineering, Stanford University, as a Research Associate for 1 year.In January 2000, he joined the University of Michigan, Ann Arbor, where heis an Assistant Professor with the Department of Mechanical Engineering. AtMichigan, he mentorsfive doctoral students who are investigating thermaltrans-port phenomena in MEMS structures and electronic devices, novel actuator,and micromechanism design for MEMS optical detection devices, multiphysics

modeling, and characterization of RF MEMS, integration of biomolecular mo-tors in NEMS/MEMS.

Dr. Kurabayashi is a recipient of the 2001 NSF CAREER Award.

Eos Actuator Jmems2005 1

Documents

Transcript of Eos Actuator Jmems2005 1