學(xué)開(kāi)叉車(chē)要注意什么？

1、Micro-sensorMicro-mirror Micro-gearMicro-accelerometerSelf Assembly and Micro/Nano Electronics東莞電工培訓(xùn) http:/ 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 tec

2、hnology. Micro-sensorMicro-mirror Micro-gearMicro-accelerometerMEMS vs. Integrated Circuits (ICs) One way to look at it: ICs 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 ca

3、n also actuate mechanical devices (switches, mirrors, etc)In the early 1980s Karlsruhe Nuclear Research Center in Germany developed LIGALIGA is a German acronym for X-ray lithography (X-ray Lithographie), Electroplating (Galvanoformung), and Molding (Abformung)It allows for manufacturing of high asp

4、ect ratio microstructuresHigh aspect ratio structures are very skinny and tallLIGA structures have precise dimensions and good surface roughnessMicrofluidic device made using LIGA processCapacitive Comb drive also made using the LIGA processIn 1986 IBM developed the atomic force microscope (AFM)The

5、AFM maps the surface of an atomic structureMeasures the force acting on the tip of a microscale cantileverIt is a very high resolution type of scanning probe microscope with a resolution of fractions of an AngstromMEMS ApplicationsPressure Sensors Auto and Bio applications Ink Jet Print Heads Accele

6、rometers (Inertial Sensors “Crash Bags”, Navigation, Safety, iPhones)MicromachinesMicro Fluidic Pumps Insulin Pump (drug delivery) Spatial Light Modulators (SLMs) MOEM Micro Optical Electro Mechanical Systems DMD Digital Mirror DeviceMass Storage DevicesChem Lab on a ChipCantilever biosensorsMEMS Pr

7、essure 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. These sensors help improve engine performance including gas mileage.Pressure SensorsTRW Commercial Gas Engine Sensor

8、 - 1985Top view of the TRW (1985) pressure sensor, the metal components are on top of the silicon membrane. The silicon membrane is stressed when there is a pressure differential.Intercardial catheter-tip sensorsThese MEMS transducers are used in intercardial catheter-tip sensors for monitoring bloo

9、d pressure during cardiac catheterization. Photo courtesy of Lucas NovaSensor, Fremont, CA. 0.15 x 0.4 x 0.9 mm Disposable Blood Pressure Sensors Disposable sensors use MEMS transducers to measure changes in blood pressure. Photo courtesy of Motorola, Sensor Products Div., Phoenix, AZ.These $10 devi

10、ces connect to a patients IV line and monitor blood pressure through the IV solution. This microphone is made from Silicon and is only millimeters large. Photo Courtesy of EmKay EmKay Sisonic MicrophoneInk JetInk jet printers are MEMS based 1979 IBM and HPInk jet printers are MEMS based 1979 IBM and

11、 HPInk Jet1979 HP Micromachined Inkjet NozzleSchematic of an array of inkjet nozzles. Close-up view of a commercial inkjet printer head illustrating the nozzles.This printing technique rapidly heats ink, creating tiny bubbles. When the bubbles collapse, the ink squirts through an array of nozzles on

12、to paper and other media. Silicon micromachining technology is used to manufacture the nozzles. The nozzlescan be made very small and can be densely packed for high resolution printing.The AccelerometerAnalog Devices 1993 Saab was the first automobile company to include MEMS accelerometers to trigge

13、r airbags. These MEMS-based systems sense rapid deceleration and in the event of a collision send a signal to inflate rapidly an airbag.The AccelerometerAn accelerometer is a sensor for testing the acceleration along a given axis. The simplest MEMS accelerometer is an inertial mass suspended by spri

14、ngs. Deflection of the mass is converted into an electrical signal.iPhoneNintendo WiiIBM Thinkpadhttp:/ square in the middle of the chip is a resistor that heats up a gas bubble. The next larger squares contain thermal couples that sense the location of the heated bubble as the device is tilted or a

15、ccelerated. (Image courtesy of MEMSIC, Inc.) MEMSICs Dual-Axis Thermal AcceleratorMEMS as Machines MEMS are often referred to as Micro Machines. Tiny devices that move things.Gear Train. Each gear tooth is 8 microns wide.Mirror (popped up)Micro Machines Surface Micromachining takes off in the 1990s.

16、 Sandia National LaboratoriesThis basically consists of alternating layers of structural materials (polycrystalline silicon) and sacrificial layers (Silicon Dioxide). The sacrificial layer is a scaffold and acts as a temporary support and spacing material. The last step of the process is the “releas

17、e” step, where the sacrificial layer is removed freeing the structural layers so they can move.In this image, the square at the top is a microfluidics device with internal passageways used for a lab on a chip. The multi-arm device (center) is a fuel injection nozzle. Bottom left is an accelerometer,

18、 and bottom right is an inductor used in RF circuits. (Image courtesy of Microfabrica Inc., .) Micromachines In this image, the square at the top is a microfluidics device with internal passageways used for a lab on a chip. The multi-arm device (center) is a fuel injection nozzle. Bottom left is an

19、accelerometer, and bottom right is an inductor used in RF circuits. (Image courtesy of Microfabrica Inc., .) Micromachines Microfluidics Device In this image, the square at the top is a microfluidics device with internal passageways used for a lab on a chip. The multi-arm device (center) is a fuel i

20、njection nozzle. Bottom left is an accelerometer, and bottom right is an inductor used in RF circuits. (Image courtesy of Microfabrica Inc., .) Micromachines Fuel Injection NozzleMicrofluidics Device In this image, the square at the top is a microfluidics device with internal passageways used for a

21、lab on a chip. The multi-arm device (center) is a fuel injection nozzle. Bottom left is an accelerometer, and bottom right is an inductor used in RF circuits. (Image courtesy of Microfabrica Inc., .) Micromachines AccelerometerFuel Injection NozzleMicrofluidics Device In this image, the square at th

22、e top is a microfluidics device with internal passageways used for a lab on a chip. The multi-arm device (center) is a fuel injection nozzle. Bottom left is an accelerometer, and bottom right is an inductor used in RF circuits. (Image courtesy of Microfabrica Inc., .) Micromachines AccelerometerFuel

23、 Injection NozzleMicrofluidics Device InductorMEMS-based Optical SwitchThese MEMS optical switches utilize micro mirrors to switch or reflect an optical channel or signal from one location to another.In 1999 Lucent Technologies developed the first optical network switchMicro Optical Electro Mechanic

24、al Systems (MOEMS)Digital Mirror Device (DMD)A DMD chip has on its surface several hundred thousand microscopic mirrors which correspond to the pixels in the image to be displayed. Digital Light Projector (DLP)Digital Mirror Device (DMD)The mirrors can be individually rotated 10-12, to an on or off

25、state.How Small are these Mirrors?Each mirror is about 16m square!DMD mirrors complete DLP units have over 2 million mirrors all functioning!Mass Storage - IBMIBMs “Millipede”100 Tera Bit per square inch!It works by making small indentations in a polymer film. Higher density data capabilityMass Stor

26、age - IBMA two-dimensional array of V-shaped silicon cantilevers, each 70 m long.Writes divot into polymer by heating tip to 400CReads by looking at surface with 300C 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

27、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.BioMEMS The overlap between microbiology and microsystem feature sizes makes integration between the two possibleAtom100 m10 m1 m0.1 m0.01 m0.001 m(1

28、 nm)Eukaryotic cellsProteinsVirusesBacteriaRibosomeNucleusGate of Leading Edge TransistorVisible LightSurface Micromachining Features (MEMS)Molecules(10 nm)Biomedical ApplicationsScientists are combining sensors and actuators with emerging biotechnologyApplications include drug delivery, DNA arrays,

29、 and microfluidicsBiomedical ApplicationsMicromachine needles used to deliver drugsProcter and GamblePlastic Needle ArrayMEMSCantilevers Cantilevers are used as Sensors Cantilevers are used as Switches Many MEMS Sensors use the principles of Cantilevers as well as RF SwtichesWhat is a Cantilever?Can

30、tilevers have a resonant frequency that depends on the length and the mass.MEMS Cantilever sensors The ends of the cantilevers are coated with a layer of probe molecules. When a target molecule is present, it attaches to the probe molecule, thereby increasing the mass. The resonant frequency goes down. You just detected the presence of a molecule!Cantilever SensorsA gold dot, about 50 nanometers in diameter, fused to the e