1

21ST CENTURYrsquoS REVOLUTION MEMS TECHNOLOGY

Kaneria Dhaval1 Ekata Mehul2

1 Pursuing MTech Embedded System UVPatel college of Engineering and Technology Kherva Mehsana India kaneriadhaval14gmailcom

2Head eiTRA - eInfochips Training and Research Academy Ahmedabad ekatamehuleitraorg

Abstractmdash We are grateful in a revolution of microelectronics

which has dramatically reduced the cost and increased the

capability of electronics This has given much potential to

prosper in the area of micro mechanics encompassing MEMS

(Micro Electro Mechanical Systems) MEMS promises to

revolutionize nearly every product category by bringing

together silicon based microelectronics with micro machining

technology making possible the realization of complete

systems on a chip often referred to as micro systems

technology are fabricated using modified silicon and non-

silicon fabrication technology It reduces cost and increases

reliability of the system MEMS is a process technology used

to create tiny integrated devices or systems that combine

mechanical and electrical componentsMEMS has been

identified as one of the most promising technologies for the

21st Century and has the potential to revolutionize both

industrial and consumer products by combining silicon based

microelectronics with micromachining technology Its

techniques and microsystem based devices have the potential

to dramatically effect of all of our lives and the way we live

If semiconductor micro fabrication was seen to be the first

micro manufacturing revolution MEMS is the second

revolution

IndexTermsmdashTechnologyFebricationPackeging Application in various fieldfuture scoperevolution

I INTRODUCTION

Micro electromechanical systems (MEMS) is a technology of miniaturization that has been largely adopted from the integrated circuit (IC) industry and applied to the miniaturization of all systems not only electrical systems but also mechanical optical fluid magnetic etc

Micro Electromechanical systems or MEMS represent an extraordinary technology that promises to transform whole industries and drive the next technological revolution These devices can replace bulky actuators and sensors with micron-scale equivalent that can be produced in large quantities by fabrication processes used in integrated circuits photolithography This reduces cost bulk weight and power consumption while increasing performance production volume and functionality by orders of magnitude For example one well known MEMS device is the accelerometer (its now being manufactured using mems low cost small size more

reliability) Furthermore it is clear that current MEMS products are simply precursors to greater and more pervasive applications to come including genetic and disease testing guidance and navigation systems power generation RF devices( especially for cell phone technology) weapon systems biological and chemical agent detection and data storage Micro mirror based optical switches have already proven their value several start-up companies specializing in their development have already been sold to large network companies for hundreds of millions of dollars The promise of MEMS is increasingly capturing the attention of new and old industrises alike as more and more of their challenges are solved with MEMS

After extensive development todays commercial MEMS ndash also known as Micro System Technologies (MST) Micro Machines (MM) have proven to be more manufacturable reliable and accurate dollar for dollar than their conventional counterparts However the technical hurdles to attain these accomplishments were often costly and time- consuming and current advances in this technology introduce newer challenges still Because this field is till in its infancy very little data on design manufacturing processes or liability are common or shared

II FEBRICATION

MEMS devices are fabricated using a number of materials depending on the application requirements One popular material is polycrystalline silicon also called ldquopolysiliconrdquo or ldquopolyrdquo This material is sculpted with techniques such as bulk or surface micro- machining and Deep Reactive Ion Etching (DRIE) proving to be fairly durable for many mechanical operations Another is nickel which can be shaped by PMMA (a form of plexiglass) mask platng (LIGA) as well as by conventional photolithographic techniques Other materials ndash such as diamond aluminum silicon carbide and gallium arsenide ndash are currently being evaluated for use in micro machines for their desirable properties eg the hardness of diamond and silicon carbide To create moveable parts several layers are needed for structural and electrical interconnect (ground plane) purposes with so-called ldquosacrificialrdquo oxide layers in between The current manufacturing record is five layers making possible a variety of complex mechanical systems These

2

capabilities developed over the last several years are beginning to unlock the almost unlimited possibilities of MEMS applications The methods used to integrate multiple patterned materials together to fabricate a completed MEMS device are just as important as the individual processes and materials themselves Depending on the type of material used fabrication techniques are classified as

A Silicon Micro fabrication

The two most general methods of MEMS integration are Surface micro machining Bulk micro machining

1 Surface Micromachining

Surface micromachining enables the fabrication of complex multicomponent integrated micromechanical

structures that would not be possible with traditional bulk micromachining This technique encases specific

structural parts of a device in layers of a sacrificial material during the fabrication process The substrate wafer is used

primarily as a mechanical support on which multiple alternating layers of structural and sacrificial material are deposited and patterned to realize micromechanical

structures The sacrificial material is then dissolved in a chemical etchant that does not attack the structural parts

The most widely used surface micromachining technique polysilicon surface micromachining uses SiO2 as the sacrificial material and polysilicon as the structural

material

Figure 1 Process flow of surface micromachining

Advantages of surface micro machining a) Structures especially thicknesses can be smaller than

10 microm in size b) The micro machined device footprint can often be much

smaller than bulk wet-etched devices c)It is easier to integrate electronics below surface micro-structures and d)Surface microstructures generally have superior tolerance compared to bulk wet-etched devices

The primary disadvantage is the fragility of surface microstructures to handling particulates and condensation during manufacturing Surface Micro machining is being

used in commercial products such as accelerometers to trigger air bags in automobiles

2 Bulk Micromachining and Wafer Bonding

Bulk micromachining is an extension of IC technology for the fabrication of 3D structures Bulk

micromachining of Si uses wet- and dry-etching techniques in conjunction with etch masks and etch stops to sculpt micromechanical devices from the Si substrate

The two key capabilities that make bulk micromachining a viable technology are

Anisotropic etchants of Si such as ethylene-diamine and

pyrocatechol (EDP) potassium hydroxide (KOH) and hydrazine (N2H4) These preferentially etch single crystal Si along given crystal planesEtch masks and etch-stop

techniques that can be used with Si anisotropic etchants to selectively prevent regions of Si from being etched Good

etch masks are provided by SiO2 and Si3N4 and some metallic thin films such as Cr and Au (gold)

Figure 2 Process flow of bulk micromachining

B Non-Silicon Micro fabrication

The development of MEMS has contributed significantly to the improvement of non-silicon micro fabrication techniques Two prominent examples are LIGA and plastic molding from micro machined substrates

1 LIGA LIGA is a German acronym standing for lithographie galvanoformung (plating) and abformung

(molding) However in practice LIGA essentially stands for a process that combines extremely thick-film resists (often gt1 mm) and x-ray lithography which can pattern

thick resists with high fidelity and results in vertical sidewalls Although some applications may require only

the tall patterned resist structures themselves other applications benefit from using the thick resist structures as plating molds (ie material can be quickly deposited

into the mold by electroplating) A drawback to LIGA is the need for high-energy x-ray sources that are very

expensive and rare

3

Figure 3 Process flow of LIGA

The LIGA process exposes PMMA (poly methyl metha crylate) plastic with synchrotron radiation through a

mask This is shown at the top of the Figure 1 Exposed PMMA is then washed away leaving vertical wall

structures with spectacular accuracy Structures a third of a millimeter high and many millimeters on a side are accurate to a few tenths of a micron Metal is then plated

into the structure replacing the PMMA that was washed away This metal piece can become the final part or can be used as an injection mold for parts made out of a variety of plastics

III MEMS DESIGN PROCESS There are three basic building blocks in MEMS

technology which areDeposition Process-the ability to deposit thin films of material on a substrate Lithography-to apply a patterned mask on top of the films by photolithograpic imaging Etching-to etch the films selectively to the mask A MEMS process is usually a structured sequence of these operations to form actual devices

Figure 4 MEMS design flow starting to end

IV PACKAGING

As with micromachining processes many MEMS sensor-packaging techniques are the same as or derived from those used in the semiconductor industry However the mechanical requirements for a sensor package are typically much more stringent than for purely microelectronic devices Microelectronic packages are often generic with plastic ceramic or metal packages being suitable for the vast majority of IC applications For example small stresses and strains transmitted to a microelectronics die will be tolerable as long as they stay within acceptable limits and do not affect reliability In the case of a MEMS physical sensor however such stresses and strains and other undesirable influences must be carefully controlled in order for the device to function correctly Failure to do so even when employing electronic compensation techniques will reduce both the sensor performance and long-term stability

Standard IC Packages

Ceramic Packages

Plastic Packages

Metal Packages

Figure 5 Standard IC packeges

A MEMS Mechanical Sensor Packaging

A MEMS sensor packaging must meet several requirements bull Protect the sensor from external influences and environmental effects Since MEMS inherently include some microscale mechanical components the integrity of the device must be protected against physical damage arising from mechanical shocks vibrations temperature cycling and particle contamination The electrical aspects of the device such as the bond wires and the electrical properties of the interconnects must also be protected against these external influences and environmental effects bull Protect the environment from the presence of the sensor In addition protecting the sensor the package must prevent the presence of the MEMS from reacting with or contaminating potentially sensitive environments The

4

classic examples of this are medical devices that contain packaged sensors that can be implanted or used within the body these must be biocompatible nontoxic and able to withstand sterilization bull Provide a controlled electrical thermal mechanical andor optical interface between the sensor its associated components and its environment Not only must the package protect both the sensor and its environment it must also provide a reliable and repeatable interface for all the coupling requirements of a particular application In the case of mechanical sensors the interface is of fundamental importance since by its nature specific mechanical coupling is essential but unwanted effects must be prevented A simple example would be a pressure sensor where the device must be coupled in some manner to the pressure but isolated from for example thermally induced strains The package must also provide reliable heat transfer to enable any heat generated to be transmitted away from the MEMS device to its environment

VAPPLICATIONS OF MEMS

ACommunications High frequency circuits will benefit considerably from advent of the RF-MEMS technology Electrical components such as inductors and tunable capacitors can be improved significantly compared to their integrated counter parts if they are made using MEMS technology If the integration of such components the performance of communication circuits will improve while the total circuit area power consumption and cost will be reduced In addition the mechanical switch as developed by several research groups is a key component with huge potential in various micro wave circuits

B Biotechnology

MEMS enabling new discoveries in science and engineering such as the polymerase chain Reaction (PCR) Microsystems for DNA amplification and identification micro machined scanning Tunneling microscopes (STMs) Biochips for detection of hazardous chemical and biological agents and Microsystems for high-throughput drug screening and selection

C Inertial sensors

Inertial sensors are mechanics sensors aiming at measuring accelerations in the mechanics science definition There are two categories of inertial sensors They are accelerometers which measures variation of rotational speed and gyroscopes which measures variation of rotational speed

D Accelerometers

Figure 6 Capacitive accelerometerrsquos working diagram(reference from

wwwsensorsmagcom)

Figure 7 Schematic of micro accelerometer ADXLseries produced by Analog Device

Figure 8 Schematic of micro accelerometer with closerview

On these diagrams we can see a micro accelerometer device and the chip including associated electronics made by Analog Device This is a two axis micro accelerometer This means it is able to measure accelerations in two directions at a time (in the directions of the plane) Micro accelerometers were the first MEMS device to flood the market Micro accelerometers measure variation of translational speed So acceleration deceleration even very high deceleration likehellipshock The sensor that detects a shock and launches the airbag is a micro accelerometer combined with a electronic circuit able to decide wether or not the shock was an accident or just your car passing a pothole There are lots of applications like navigation micro accelerometers can help in increasing precision There are more and more to say about micro accelerometers they are still the spearhead of MEMS industry

E Gyroscopes

Micro gyroscopes are newer in the market compared to micro accelerometers Some devices have appeared on the market for navigation application The key point in these devices is sensitivity

F RF switches

RF switches have been under development for years but the commercial applications just begin to appear The reason is the difficulty to combine high efficiency reproducibility and reliability RF switches will be preferred to full electronic switches on applications where security integration capabilities power consumption and other parameters are critical

G Consumer Market

3

Figure 3 Process flow of LIGA

The LIGA process exposes PMMA (poly methyl metha crylate) plastic with synchrotron radiation through a

mask This is shown at the top of the Figure 1 Exposed PMMA is then washed away leaving vertical wall

structures with spectacular accuracy Structures a third of a millimeter high and many millimeters on a side are accurate to a few tenths of a micron Metal is then plated

into the structure replacing the PMMA that was washed away This metal piece can become the final part or can be used as an injection mold for parts made out of a variety of plastics

III MEMS DESIGN PROCESS There are three basic building blocks in MEMS

technology which areDeposition Process-the ability to deposit thin films of material on a substrate Lithography-to apply a patterned mask on top of the films by photolithograpic imaging Etching-to etch the films selectively to the mask A MEMS process is usually a structured sequence of these operations to form actual devices

Figure 4 MEMS design flow starting to end

IV PACKAGING

As with micromachining processes many MEMS sensor-packaging techniques are the same as or derived from those used in the semiconductor industry However the mechanical requirements for a sensor package are typically much more stringent than for purely microelectronic devices Microelectronic packages are often generic with plastic ceramic or metal packages being suitable for the vast majority of IC applications For example small stresses and strains transmitted to a microelectronics die will be tolerable as long as they stay within acceptable limits and do not affect reliability In the case of a MEMS physical sensor however such stresses and strains and other undesirable influences must be carefully controlled in order for the device to function correctly Failure to do so even when employing electronic compensation techniques will reduce both the sensor performance and long-term stability

Standard IC Packages

Ceramic Packages

Plastic Packages

Metal Packages

Figure 5 Standard IC packeges

A MEMS Mechanical Sensor Packaging

A MEMS sensor packaging must meet several requirements bull Protect the sensor from external influences and environmental effects Since MEMS inherently include some microscale mechanical components the integrity of the device must be protected against physical damage arising from mechanical shocks vibrations temperature cycling and particle contamination The electrical aspects of the device such as the bond wires and the electrical properties of the interconnects must also be protected against these external influences and environmental effects bull Protect the environment from the presence of the sensor In addition protecting the sensor the package must prevent the presence of the MEMS from reacting with or contaminating potentially sensitive environments The

4

classic examples of this are medical devices that contain packaged sensors that can be implanted or used within the body these must be biocompatible nontoxic and able to withstand sterilization bull Provide a controlled electrical thermal mechanical andor optical interface between the sensor its associated components and its environment Not only must the package protect both the sensor and its environment it must also provide a reliable and repeatable interface for all the coupling requirements of a particular application In the case of mechanical sensors the interface is of fundamental importance since by its nature specific mechanical coupling is essential but unwanted effects must be prevented A simple example would be a pressure sensor where the device must be coupled in some manner to the pressure but isolated from for example thermally induced strains The package must also provide reliable heat transfer to enable any heat generated to be transmitted away from the MEMS device to its environment

VAPPLICATIONS OF MEMS

ACommunications High frequency circuits will benefit considerably from advent of the RF-MEMS technology Electrical components such as inductors and tunable capacitors can be improved significantly compared to their integrated counter parts if they are made using MEMS technology If the integration of such components the performance of communication circuits will improve while the total circuit area power consumption and cost will be reduced In addition the mechanical switch as developed by several research groups is a key component with huge potential in various micro wave circuits

B Biotechnology

MEMS enabling new discoveries in science and engineering such as the polymerase chain Reaction (PCR) Microsystems for DNA amplification and identification micro machined scanning Tunneling microscopes (STMs) Biochips for detection of hazardous chemical and biological agents and Microsystems for high-throughput drug screening and selection

C Inertial sensors

Inertial sensors are mechanics sensors aiming at measuring accelerations in the mechanics science definition There are two categories of inertial sensors They are accelerometers which measures variation of rotational speed and gyroscopes which measures variation of rotational speed

D Accelerometers

Figure 6 Capacitive accelerometerrsquos working diagram(reference from

wwwsensorsmagcom)

Figure 7 Schematic of micro accelerometer ADXLseries produced by Analog Device

Figure 8 Schematic of micro accelerometer with closerview

On these diagrams we can see a micro accelerometer device and the chip including associated electronics made by Analog Device This is a two axis micro accelerometer This means it is able to measure accelerations in two directions at a time (in the directions of the plane) Micro accelerometers were the first MEMS device to flood the market Micro accelerometers measure variation of translational speed So acceleration deceleration even very high deceleration likehellipshock The sensor that detects a shock and launches the airbag is a micro accelerometer combined with a electronic circuit able to decide wether or not the shock was an accident or just your car passing a pothole There are lots of applications like navigation micro accelerometers can help in increasing precision There are more and more to say about micro accelerometers they are still the spearhead of MEMS industry

E Gyroscopes

Micro gyroscopes are newer in the market compared to micro accelerometers Some devices have appeared on the market for navigation application The key point in these devices is sensitivity

F RF switches

RF switches have been under development for years but the commercial applications just begin to appear The reason is the difficulty to combine high efficiency reproducibility and reliability RF switches will be preferred to full electronic switches on applications where security integration capabilities power consumption and other parameters are critical

G Consumer Market

4

classic examples of this are medical devices that contain packaged sensors that can be implanted or used within the body these must be biocompatible nontoxic and able to withstand sterilization bull Provide a controlled electrical thermal mechanical andor optical interface between the sensor its associated components and its environment Not only must the package protect both the sensor and its environment it must also provide a reliable and repeatable interface for all the coupling requirements of a particular application In the case of mechanical sensors the interface is of fundamental importance since by its nature specific mechanical coupling is essential but unwanted effects must be prevented A simple example would be a pressure sensor where the device must be coupled in some manner to the pressure but isolated from for example thermally induced strains The package must also provide reliable heat transfer to enable any heat generated to be transmitted away from the MEMS device to its environment

VAPPLICATIONS OF MEMS

ACommunications High frequency circuits will benefit considerably from advent of the RF-MEMS technology Electrical components such as inductors and tunable capacitors can be improved significantly compared to their integrated counter parts if they are made using MEMS technology If the integration of such components the performance of communication circuits will improve while the total circuit area power consumption and cost will be reduced In addition the mechanical switch as developed by several research groups is a key component with huge potential in various micro wave circuits

B Biotechnology

MEMS enabling new discoveries in science and engineering such as the polymerase chain Reaction (PCR) Microsystems for DNA amplification and identification micro machined scanning Tunneling microscopes (STMs) Biochips for detection of hazardous chemical and biological agents and Microsystems for high-throughput drug screening and selection

C Inertial sensors

Inertial sensors are mechanics sensors aiming at measuring accelerations in the mechanics science definition There are two categories of inertial sensors They are accelerometers which measures variation of rotational speed and gyroscopes which measures variation of rotational speed

D Accelerometers

Figure 6 Capacitive accelerometerrsquos working diagram(reference from

wwwsensorsmagcom)

Figure 7 Schematic of micro accelerometer ADXLseries produced by Analog Device

Figure 8 Schematic of micro accelerometer with closerview

On these diagrams we can see a micro accelerometer device and the chip including associated electronics made by Analog Device This is a two axis micro accelerometer This means it is able to measure accelerations in two directions at a time (in the directions of the plane) Micro accelerometers were the first MEMS device to flood the market Micro accelerometers measure variation of translational speed So acceleration deceleration even very high deceleration likehellipshock The sensor that detects a shock and launches the airbag is a micro accelerometer combined with a electronic circuit able to decide wether or not the shock was an accident or just your car passing a pothole There are lots of applications like navigation micro accelerometers can help in increasing precision There are more and more to say about micro accelerometers they are still the spearhead of MEMS industry

E Gyroscopes

Micro gyroscopes are newer in the market compared to micro accelerometers Some devices have appeared on the market for navigation application The key point in these devices is sensitivity

F RF switches

RF switches have been under development for years but the commercial applications just begin to appear The reason is the difficulty to combine high efficiency reproducibility and reliability RF switches will be preferred to full electronic switches on applications where security integration capabilities power consumption and other parameters are critical

G Consumer Market

5

Sports Training Devicesomputer Peripherals Car and Personal Navigation DevicesActive Subwoofers etc

H Industrial Market

Earthquake Detection and Gas ShutoffMachine Health Shock and Tilt Sensing etc

I Military

TanksPlanesEquipment for Soldier etc

Table I Application of MEMS in various fields

VI THE FUTURE OF MEMS TECHNOLOGY

A Industry Challenges Some of the major challenges facing the MEMS

industry include 1 Access to Foundries

MEMS companies today have very limited access to MEMS fabrication facilities or foundries for prototype and device manufacture In addition the majority of the organizations expected to benefit from this technology currently do not have the required capabilities and competencies to support MEMS fabrication For example telecommunication companies do not currently maintain micromachining facilities for the fabrication of optical switches Affordable and receptive access to MEMS fabrication facilities is crucial for the commercialization of MEMS

2 Design Simulation and Modelling Due to the highly integrated and interdisciplinary

nature of MEMS it is difficult to separate device design from the complexities of fabrication Consequently a high level of manufacturing and fabrication knowledge is necessary to design a MEMS device Furthermore considerable time and expense is spent during this development and subsequent prototype stage In order to increase innovation and creativity and reduce unnecessary lsquotime-to-marketrsquo costs an interface should be created to separate design and fabrication As successful device

development also necessitates modelling and simulation it is important that MEMS designers have access to adequate analytical tools

3 Packaging and Testing The packaging and testing of devices is probably

the greatest challenge facing the MEMS industry As previously described MEMS packaging presents unique problems compared to traditional IC packaging in that a MEMS package typically must provide protection from an operating environment as well as enable access to it Currently there is no generic MEMS packaging solution with each device requiring a specialized format Consequently packaging is the most expensive fabrication step and often makes up 90 (or more) of the final cost of a MEMS device

4 Standardization Due to the relatively low number of commercial

MEMS devices and the pace at which the current technology is developing standardization has been very difficult To date high quality control and basic forms of standardization are generally only found at multi-million dollar (or billion dollar) investment facilities However in 2000 progress in industry communication and knowledge sharing was made through the formation of a MEMS trade organization Based in Pittsburgh USA the MEMS industry group (MEMS-IG) with founding members including Xerox Corning Honeywell Intel and JDS Uniphase grew out of study teams sponsored by DARPA that identified a need for technology road mapping and a source for objective statistics about the MEMS industry In addition a MEMS industry roadmap sponsored by the Semiconductor Equipment and Materials International organization (SEMI)

5 Education and Training The complexity and interdisciplinary nature of

MEMS require educated and well-trained scientists and engineers from a diversity of fields and backgrounds The current numbers of qualified MEMS-specific personnel is relatively small and certainly lower than present industry demand Education at graduate level is usually necessary and although the number of universities offering MEMS-based degrees is increasing gaining knowledge is an expensive and time-consuming process Therefore in order to match the projected need for these MEMS scientists and engineers an efficient and lower cost

VII CONCLUSIONS

MEMS promises to revolutionize nearly every product category by bringing together silicon-based microelectronics with micromachining technology making possible the realization of complete systems-on-a-chipFuture Work

MEMS will be the indispensable factor for advancing technology in the 21st century and it promises to create entirely new categories of products

The automotive industry motivated by the need for more efficient safety systems and the desire for enhanced performance is the largest consumer of MEMS-based technology In addition to accelerometers and

6

gyroscopes micro-sized tire pressure systems are now standard issues in new vehicles putting MEMS pressure sensors in high demand Such micro-sized pressure sensors can be used by physicians and surgeons in a telemetry system to measure blood pressure at a stet allowing early detection of hypertension and restenosis Alternatively the detection of bio molecules can benefit most from MEMS-based biosensors Medical applications include the detection of DNA sequences and metabolites MEMS biosensors can also monitor several chemicals simultaneously making them perfect for detecting toxins in the environment

REFERENCES

[1] Teymoori MM Asadollahi HlsquorsquoMEMS Based Medical MicrosensorsrsquorsquoComputer and Electrical Engineering 2009 ICCEE 09 Second International Conference on Vol1 Digital Object Identifier 101109ICCEE200980 Publication Year 2009Page(s) 158- 162

[2] Sethuramalingam TK Vimalajuliet A ldquoDesign of MEMS based capacitive accelerometerrdquoMechanical and Electrical Technology (ICMET) 2010 2nd International Conference on Digital Object Identifier 101109ICMET20105598424 Publication Year 2010 Page(s) 565- 568

[3] Lyshevski SEldquoMicro-electromechanical systems motion control of micro-actuatorsrdquoDecision and Control 1998 Proceedings of the 37th IEEE Conference on Vol4

[4] Digital Object Identifier 101109CDC1998761988 Publication Year 1998 Page(s) 4334- 4335

[5] MEMS technology design CAD and applications

[6] Lal R Apte PR Bhat KN Bose G Chandra S Sharma DKrdquoMEMS technology design CAD and applicationsrdquo Design Automation Conference 2002 Proceedings of ASP-DAC 2002 7th Asia and South Pacific and the 15th International Conference on VLSI Design ProceedingsDigital Object Identifier 101109ASPDAC2002994879 Publication Year 2002 Page(s) 24- 25

[7] Fujita H ldquoA decade of MEMS and its futurerdquoMicro Electro Mechanical Systems 1997 MEMS 97 Proceedings IEEE Tenth Annual International Workshop on Digital Object Identifier 101109MEMSYS1997581729 Publication Year 1997 Page(s) 1- 7

[8] ONeal CB Malshe AP Singh SB Brown WD Eaton WP rdquoChallenges in the packaging of MEMSrdquo Advanced Packaging Materials Processes Properties and Interfaces 1999 Proceedings International Symposium on Digital Object Identifier 101109ISAPM1999757284 Publication Year 1999 Page(s) 41- 47

[9] Petersen KrdquoMEMS in the coming decaderdquoNanoMicro Engineered and Molecular Systems (NEMS) 2010 5th IEEE International Conference on Digital Object Identifier 101109NEMS20105592523 Publication Year 2010 Page(s) 1- 9

[10] Mansour RR Bakri-Kassem M Daneshmand M Messiha NrdquoRF MEMS devicesrdquo MEMS NANO and Smart Systems 2003 Proceedings International Conference on Digital Object Identifier 101109ICMENS20031221974 Publication Year 2003 Page(s) 103- 107

[11] Tjerkstra R W de Boer M Berenschot E Gardeniers JGE van der Berg A and Elwenspoek M ldquoEtching Technology for MicrochannelsrdquoProceedings of the 10th Annual Workshop of Micro Electro Mechanical Systems(MEMS rsquo97) Nagoya Japan Jan 26-30 1997 pp 396-398

[12] Journal of Microelectromechanical Systems (httpwwwieeeorgpub_previewmems_tochtml)

[13] Journal of Micromechanics and Microengineering (httpwwwioporgJournalsjm)

[14] Berkeley Sensor and Actuator Center httpbsaceecsberkeley

[15] University of Stanford httpwwwstanfordedugroupSMLee321hoMEMS-01-intro

[16] Free scale semiconductor httpwwwfreescalecom

6

gyroscopes micro-sized tire pressure systems are now standard issues in new vehicles putting MEMS pressure sensors in high demand Such micro-sized pressure sensors can be used by physicians and surgeons in a telemetry system to measure blood pressure at a stet allowing early detection of hypertension and restenosis Alternatively the detection of bio molecules can benefit most from MEMS-based biosensors Medical applications include the detection of DNA sequences and metabolites MEMS biosensors can also monitor several chemicals simultaneously making them perfect for detecting toxins in the environment

REFERENCES

[1] Teymoori MM Asadollahi HlsquorsquoMEMS Based Medical MicrosensorsrsquorsquoComputer and Electrical Engineering 2009 ICCEE 09 Second International Conference on Vol1 Digital Object Identifier 101109ICCEE200980 Publication Year 2009Page(s) 158- 162

[2] Sethuramalingam TK Vimalajuliet A ldquoDesign of MEMS based capacitive accelerometerrdquoMechanical and Electrical Technology (ICMET) 2010 2nd International Conference on Digital Object Identifier 101109ICMET20105598424 Publication Year 2010 Page(s) 565- 568

[3] Lyshevski SEldquoMicro-electromechanical systems motion control of micro-actuatorsrdquoDecision and Control 1998 Proceedings of the 37th IEEE Conference on Vol4

[4] Digital Object Identifier 101109CDC1998761988 Publication Year 1998 Page(s) 4334- 4335

[5] MEMS technology design CAD and applications

[6] Lal R Apte PR Bhat KN Bose G Chandra S Sharma DKrdquoMEMS technology design CAD and applicationsrdquo Design Automation Conference 2002 Proceedings of ASP-DAC 2002 7th Asia and South Pacific and the 15th International Conference on VLSI Design ProceedingsDigital Object Identifier 101109ASPDAC2002994879 Publication Year 2002 Page(s) 24- 25

[7] Fujita H ldquoA decade of MEMS and its futurerdquoMicro Electro Mechanical Systems 1997 MEMS 97 Proceedings IEEE Tenth Annual International Workshop on Digital Object Identifier 101109MEMSYS1997581729 Publication Year 1997 Page(s) 1- 7

[8] ONeal CB Malshe AP Singh SB Brown WD Eaton WP rdquoChallenges in the packaging of MEMSrdquo Advanced Packaging Materials Processes Properties and Interfaces 1999 Proceedings International Symposium on Digital Object Identifier 101109ISAPM1999757284 Publication Year 1999 Page(s) 41- 47

[9] Petersen KrdquoMEMS in the coming decaderdquoNanoMicro Engineered and Molecular Systems (NEMS) 2010 5th IEEE International Conference on Digital Object Identifier 101109NEMS20105592523 Publication Year 2010 Page(s) 1- 9

[10] Mansour RR Bakri-Kassem M Daneshmand M Messiha NrdquoRF MEMS devicesrdquo MEMS NANO and Smart Systems 2003 Proceedings International Conference on Digital Object Identifier 101109ICMENS20031221974 Publication Year 2003 Page(s) 103- 107

[11] Tjerkstra R W de Boer M Berenschot E Gardeniers JGE van der Berg A and Elwenspoek M ldquoEtching Technology for MicrochannelsrdquoProceedings of the 10th Annual Workshop of Micro Electro Mechanical Systems(MEMS rsquo97) Nagoya Japan Jan 26-30 1997 pp 396-398

[12] Journal of Microelectromechanical Systems (httpwwwieeeorgpub_previewmems_tochtml)

[13] Journal of Micromechanics and Microengineering (httpwwwioporgJournalsjm)

[14] Berkeley Sensor and Actuator Center httpbsaceecsberkeley

[15] University of Stanford httpwwwstanfordedugroupSMLee321hoMEMS-01-intro

[16] Free scale semiconductor httpwwwfreescalecom