个人简历• 美国大学工程学学士、硕士、博士• 美国德州电子仪器公司芯片测试工程师，芯片生产工程师，开发部经理。

• 美国阿肯色大学电子工程学教授。• 发表论文 170多篇。• 完成多项研究项目，价值超过美金 1500万。

个人简历

• 博士生导师，指导过 65位博士和硕士生。• 获得伦敦城市行业教育学会的“ CGIA”文凭。

• 写了关于开关电源技术方面的书一本，书名为“ Power Switching Converters”

• 美国电解化学协会委员。• 微电子封装研究所主任。

University of Arkansas

Micro-Electro-Mechanical Devices

Simon S. Ang

Professor of Electrical EngineeringUniversity of Arkansas

USA

What is Micro-Electromechanical Device or MEMs?

• Imagine machines so small they are imperceptible to the human eye.

• Imagine working machines with gears no bigger than a grain of pollen.

What is MEMS?

• Micro-Electro-Mechanical Systems (MEMS) is the integration of mechanical elements, sensors, actuators, and electronics on a common substrate using micro-fabrication technology.

MEMS Applications

• Air Bag Sensor - crash-bag deployment in automobile (accelerometer)

• Ink Jet Printer

• Bio-MEMS – Polymerase Chain Reactor (PCR) for DNA amplification and identification

MEMS Accelerometer

Automotive --  Testing, Suspension, Air BagsAgricultural --  Harvesting shock & vibration, Production line monitoring

Manufacturing -- Testing, Production line monitoring, Shipping monitoringTransportation  --  Rail-car sensing, Shipping monitoring, Testing

Down Hole Drilling -- Tilt/Attitude sensing, Machinery healthNASA -- Vibration Monitoring, Testing

(From Silicon Design Inc.,)

A Portable PCR DeviceBiological Detection Technology for Counter –

Terrorism

(Lawrence Livermore Laboratory)

Sandia’s Micro-Mirror

Spider Mite on a Sandia’s Micro-Mirror

Spider Mite Approaching a Sandia’s Micro-Gear Assembly

Micro Spacecrafts

Microthruster

Microthruster

Microcombustion testing

Microthruster

Microthruster firing sequence

Basic Surface Micromachining Process Sequence

I. Deposit Sacrificial Layer

II. Pattern Sacrificial Layer

III. Deposit Mechanical Layer

IV. Pattern Mechanical Layer

V. Release Mechanical Layer

VI. Test Device

+V

Microelectronic Fabrication

Photomask Fabricated Devices

Processing Equipment

Processing Equipment

Processing Equipment

Processing Equipment

Processing Equipment

Processing Equipment

Processing Equipment

Aluminum Wire Bonder

Gold Wire Bonder

Wire Bond Pull Tester

Measurement Equipment

Microelectronic Cleanroom Operation

Microelectronic Cleanroom Operation

Microelectronic Cleanroom Operation

Microelectronic Cleanroom Operation

Microelectronic Cleanroom Operation

Microelectronic Cleanroom Operation

Wire Bonding

Microfluidic Devices

• Microfluidic devices are MEMS devices with micro-scale (10-6m) or nano-scale (10-9m) flow channels

• They come with valves, electrodes, heaters, and other features

• These microfluidic devices can be used as tiny chemical processing or reaction system, consuming only tiny amount of chemical – micro-TAS (micro total analysis system)

Post-type Filter

Comb-Type Filter

Weir-type Filter

Glass cover

Silicon plate

Inlet Outlet

50µm

Weir-type Filter

50µm

Fluorescent Microscope

Cell Fluorescent labeled antibody Labeled cell

Labeling

Detection

In Chip Immunofluorescent Cell Detection

Glass cover

Silicon Plate

Beads in the Microchannels

Deep channel (before filter chamber)

Shallow channel (After filter chamber)

Confocal Images of Microchannel

Shallow channel

Deep Channel

Fluent Simulations of Microfilter Chip

1μm weir gap

Flow rate=2 mm/s

3μm weir gap

Flow rate=2mm/s

6μm weir gap

Flow rate=2mm/s9μm weir gap

Flow rate=2mm/s

Fluent Simulations of Microfilter Chip

50µm

1μm weir gap

Depth=30μmDepth=10μm

Depth=50μm

Flow rate=1mm/sFlow rate=0.5mm/s

Labeling efficiency along the weir

0

10

20

30

40

50

0 20 40 60 80 100 120

Normalized S/N ratio

Dept

h of

Wei

r

Trapping Efficiency

Comparison with the conventional detection on slides

• On slides– 9 steps– Takes more than

1 h– Consumes 20µl

cells solution and 25 µl labeling reagent

• Within filter chip– 3 steps– Takes less than

0.5h– Consumes 2 µl

cells solution and labeling reagent

Pillar-Type Microfludic Filter Chip

Future work

• Next generation chip:– Comb-type chip– Multiplex

• Application in DNA array• Application in ELISA• Incorporate QD

Other Related Work

• Quantum dot labeling

• Bacteria sensors

• Brain probes

• Recording integrated circuitries

• Microelectronics Packaging

Quantum Dots Detection System

Quantum Dots Labeling of C. parvum (red) and G. Lamblia (Green)

“Quantum Dots as a Novel Immunofluorescent Detection System for Cryptosporidium parvum and Giardia lamblia,” L. Zhu, S. Ang, & Wen-Tso Liu, in Applied and Environmental Microbiology.

Interdigitated Electrode Sensor

What is a Bio-Sensor?

• Biologically sensitive Material– Antibodies– Enzymes– DNA Probes

• Transducing Element/System– Electrochemical– Optical– mass

• Interfacing– Fluorescent– Chemiluminescent– Enzymatic substrate

Direct

Indirect

E-coli Sensing Principle

Au Electrode

E. coli O157:H7 cells

Fe[(CN)6]3-/4-

Charge transfer is

blocked

Streptavidin Self

Assembled Monolayer

E-coli cells on the surface of bio-sensor before washing away non-specific binding - 65 x 100 μm window size

1000 X Magnification

Scanning Electron Micrograph of E-Coli on Bio-Sensor

Surface of Electrode (AFM)

• Multi-site potential and chronoamperometry brain probes

Brain Sensors

Neural Signal Recording Electrodes

Nano Interdigitated Array Electrochemical Recording Electrode

Potential Electrode

• A brain probe mounted and wire bonded on a circuit board carrier

Brain Sensors

• SEM Photo of a multi-site potential and chrono-amperometry brain probe

Brain Sensors

• SEM Photo of a multi-site potential and chrono-amperometry brain probe

Brain Sensors

Silicon Microprobe Process Flow

Silicon Microprobe Process Flow

Brain Probe Recording in Rat’s Brain

Extracellular Field Potentials in Olfactory Bulb of A Male Rat

Stainless steel microwires - 100µm diameter, enamel-insulated

16-site brain microprobe

A) Match in evoked potential amplitude and waveform across the four recording sites when occupying the same position in the olfactory bulb

B) Sharp reversal of polarity as each recording site across the mitral cell later, indicating that crosstalk between channels is minimal.

Recording Integrated Circuit

Microelectronic Packaging

Microelectronic Packaging

Microelectronic Packaging

Microelectronic Packaging

Microelectronic Packaging

Thank You

Questions ?