05-12-2012, 12:23 PM
Self Assembly and Micro/Nano Electronics
[attachment=42572]
What are MEMS/NEMS?
Micro-Electro-Mechanical Systems (MEMS) are the integration of mechanical elements, sensors, actuators, and electronics on a common silicon substrate through microfabrication technology.
MEMS vs. Integrated Circuits (IC’s)
MEMS vs. Integrated Circuits (IC’s)
One way to look at it:
IC’s move and sense electrons
MEMS move and sense mass
MEMS act as transducers (sensors) converting a physical property into an electrical property (force to voltage, etc…).
MEMS can also actuate mechanical devices (switches, mirrors, etc…)
1982 LIGA Process Introduced
In the early 1980s Karlsruhe Nuclear Research Center in Germany developed LIGA
LIGA is a German acronym for X-ray lithography (X-ray Lithographie), Electroplating (Galvanoformung), and Molding (Abformung)
It allows for manufacturing of high aspect ratio microstructures
High aspect ratio structures are very skinny and tall
LIGA structures have precise dimensions and good surface roughness
1986 Invention of the AFM
In 1986 IBM developed the atomic force microscope (AFM)
The AFM maps the surface of an atomic structure
Measures the force acting on the tip of a microscale cantilever
It is a very high resolution type of scanning probe microscope with a resolution of fractions of an Angstrom
MEMS Applications
Pressure Sensors
Auto and Bio applications
Ink Jet Print Heads
Accelerometers
(Inertial Sensors – “Crash Bags”, Navigation, Safety, iPhones)
Micromachines
Micro Fluidic Pumps
Insulin Pump (drug delivery)
Spatial Light Modulators (SLM’s)
MOEM – Micro Optical Electro Mechanical Systems
DMD – Digital Mirror Device
Mass Storage Devices
Chem Lab on a Chip
Cantilever biosensors
MEMS Pressure Sensors
Pressure Sensors
Use piezoresistive silicon sensors
The silicon chip flexes as pressure changes
The amount the silicon chip flexes determines the output voltage signal.
Mass Storage - IBM
A two-dimensional array of V-shaped silicon cantilevers, each 70 µm long.
Writes divot into polymer by heating tip to 400°C
Reads by looking at surface with 300°C tip (measures resistance change with temp drop)
– if the tip is in a divot, the tip cools more than if it is not – therefore, there is a change in resistivity which is measured by the electronics.
Erases by making an offset pit, which causes the nearby pit to “pop up” and hence erases it.
Biomedical Applications
Scientists are combining sensors and actuators with emerging biotechnology
Applications include drug delivery, DNA arrays, and microfluidics
MEMS Cantilevers
Cantilevers are used as Sensors
Cantilevers are used as Switches
Many MEMS Sensors use the principles of Cantilevers as well as RF Swtiches
[attachment=42572]
What are MEMS/NEMS?
Micro-Electro-Mechanical Systems (MEMS) are the integration of mechanical elements, sensors, actuators, and electronics on a common silicon substrate through microfabrication technology.
MEMS vs. Integrated Circuits (IC’s)
MEMS vs. Integrated Circuits (IC’s)
One way to look at it:
IC’s move and sense electrons
MEMS move and sense mass
MEMS act as transducers (sensors) converting a physical property into an electrical property (force to voltage, etc…).
MEMS can also actuate mechanical devices (switches, mirrors, etc…)
1982 LIGA Process Introduced
In the early 1980s Karlsruhe Nuclear Research Center in Germany developed LIGA
LIGA is a German acronym for X-ray lithography (X-ray Lithographie), Electroplating (Galvanoformung), and Molding (Abformung)
It allows for manufacturing of high aspect ratio microstructures
High aspect ratio structures are very skinny and tall
LIGA structures have precise dimensions and good surface roughness
1986 Invention of the AFM
In 1986 IBM developed the atomic force microscope (AFM)
The AFM maps the surface of an atomic structure
Measures the force acting on the tip of a microscale cantilever
It is a very high resolution type of scanning probe microscope with a resolution of fractions of an Angstrom
MEMS Applications
Pressure Sensors
Auto and Bio applications
Ink Jet Print Heads
Accelerometers
(Inertial Sensors – “Crash Bags”, Navigation, Safety, iPhones)
Micromachines
Micro Fluidic Pumps
Insulin Pump (drug delivery)
Spatial Light Modulators (SLM’s)
MOEM – Micro Optical Electro Mechanical Systems
DMD – Digital Mirror Device
Mass Storage Devices
Chem Lab on a Chip
Cantilever biosensors
MEMS Pressure Sensors
Pressure Sensors
Use piezoresistive silicon sensors
The silicon chip flexes as pressure changes
The amount the silicon chip flexes determines the output voltage signal.
Mass Storage - IBM
A two-dimensional array of V-shaped silicon cantilevers, each 70 µm long.
Writes divot into polymer by heating tip to 400°C
Reads by looking at surface with 300°C tip (measures resistance change with temp drop)
– if the tip is in a divot, the tip cools more than if it is not – therefore, there is a change in resistivity which is measured by the electronics.
Erases by making an offset pit, which causes the nearby pit to “pop up” and hence erases it.
Biomedical Applications
Scientists are combining sensors and actuators with emerging biotechnology
Applications include drug delivery, DNA arrays, and microfluidics
MEMS Cantilevers
Cantilevers are used as Sensors
Cantilevers are used as Switches
Many MEMS Sensors use the principles of Cantilevers as well as RF Swtiches