Aero MEMS. Micro electronics. Pressure sensor Shear stress sensor Hot wire sensor

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1 Aero MEMS Micro electronics Pressure sensor Shear stress sensor Hot wire sensor Micro flap Micro bubble Micro injector M 3 System (Micro electronics, Micro sensor & Micro actuator) for aerodynamic and flow control Micro mechanism Micro Air Vehicle 1

2 Micro Nozzle for Spacecraft & Satellite Thrust Design the nozzle geometry to minimize the loss and increase the available thrust. 2

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4 Gas Turbine Engine Fuel Atomizer Fuel enters the swirl chamber through the tangential slots etched in the silicon. Fuel thus achieves a high angular velocity, attaching itself to the wall and creats an air cored vortex. The furl exits the orifice under both axial and radial forces in the form of a hollow conical sheet. By Prof. Mehrengany at CWRU Fluidic/BIO MEMS Microchannel applications Bio sensors Chemical sensors Flow sensor/meters Micro mixers Micro valves Micro pumps Micro PCR Micro Total Analysis System (μtas) for Biomedical applications Micro electronics & Bio- informatics 4

5 Micro Flow Cytometry Micro Mixer Re = ρul/ μ Re = 2000 ~ 6000 => turbulence Chemical reaction and stop in 100μs T D = L 2 /D T D = diffusion mixing time scale L = mixing length D = diffusion coefficient Maximize the area of contact and increase the dwelling time to complete the mixing process. 5

6 Diffusion-based Extractor: H-Filter by Prof. Paul Yager & Prof. Fred K. Forster at UW The principle of the H-filter is shown at left. In the center of the device, streams move in parallel, and diffusion causes equilibration of small molecules across the channel, whereas larger particles do not equilibrate during the transit time of the device. 1μm thermal oxidation Patterned flow channel by photolithography Patterned through hole by photolithography EDP etching through holes Remove the silicon dioxide Etch 10μm into the silicon wafer Anodic bonding with pyrex glass Fluidic Amplifiers and Logic Low resistance to fluid flow in the forward direction and high resistance to flow in reverse direction Coanda effects: Flow emerging from a free jet opening will tend to follow nearby angles or curved surfaces. Fluidic oscillator 6

7 Fluidic oscillator Fluidic Amplifiers and Logic Passive: Microvalve (I) 7

8 Active: Piezoelectric Thermal bimorph Microvalve (II) Thermopneumatic Electromagnetic Electrostatic Electrostatic bistable Pneumatic Piezoelectric: Micro Pump (I) Shape memory alloy: Micromachined pump based on thick-film piezoelectric actuation (Koch et. al. Trans 97) Electrostatic: (Zengerle et. al. MEMS 95) Shape-memory alloy actuated micropump (Bernard et. al. Trans 97) 8

9 Micro Pump (II) No Moving Part Valve (NMPV) Pump Design of the no moving part valve (NMPV) pump to be employed. Figures at left are a side schematic and the lithographic mask used. The regions shown in black are etched into Si and covered with a Pyrex sheet, as shown above. Deflections of the Pyrex cover result in flow through both inlet and outlet. The valves permit more fluid to exit the pump to the right than the left on each cycle. At right is a scanning electron micrograph of the valve region. Diffuser pump: Micro Pump (III) (Stemme et. al. S&A 1993) Gear pump: Silicon micro pump with diffuser passive valves (Gerlach et. al. Trans 97) LIGA-fabricated, self-priming, in-line gear pump (Dewa et. al. Trans 97) 9

10 Micro Pump (IV) Magnetohydrodynamic (MHD) micropump (Lemoff et. al. Trans 99) Electrochemical micropump (Bohm et. al. Trans 99) Electrohydrodynamic (EHD) pump (Richter et. al. S&A 1991) Micro Capillary Electrophoresis (μce) Under an applied electric field, ions will move at characteristic velocities determined by their charges, radii and mobility. Electrophoresis can be used to: separate a sample into its constituent species for analysis pump liquids or ions in a microchannel. meter liquids Double T microchannel as a micro flow meter 10

11 Ultrasonic Microfluidic Devices Micromachined ultrasonic devices to perform fluidic functions such as pumping, stirring, filtering, and manipulation of gases and liquids, cells, bacteria, and other biological substances Flexible plate-wave (FPW) pump f = V p / P f: frequency of applied voltage. V p : phase velocity P: spatial period of transducers. Ref: Prof. Richard White U-C Berkeley Flexible plate-wave (FPW) Pump Fabrication FPW pump package Photograph showing a wafer of FPW devices, a single FPW die mounted in a zero insertion force package, and an oscillator board Ref: Prof. Richard White U-C Berkeley 11

12 Flexible plate-wave (FPW) pump Testing Ref: Prof. Richard White U-C Berkeley Applications FPW Devices (I) Pump & hydrodynamics focusing Electroplating =>Mixer Re-entrant flexural plate-wave pump. View looking down onto membrane of ultrasonic device in diamond-shaped chamber fitted from beneath with unidirectional transducers, one sees 2-micron marker spheres that have been channeled by ultrasonic stranding waves while being pumped around the diamond as a result of acoustic streaming. Result shows ability to manipulate and move cell-sized objects. Ref: Prof. Richard White U-C Berkeley 12

13 Applications FPW Devices (II) Fusion protein NP5 Mc5-Np5 label with 10nm gold particles BrE-Ag- Mc5 Ultrasonically driven micromachined silicon needle Originally designed for surgery, when its tip is immersed in a liquid and the needle is driven ultrasonically, the hollow shaft acts as a pump. It can also be used as an ultrasonic source for lysing cells. Ref: Prof. Richard White U-C Berkeley Ultrasonic Immunoassay for Breast cancer detector Monoclonal antibody Mc5 Gold particles are mass enhanced in silver developer or breast epithelial mucin antigen BrE-Ag (Breast cancer) Fusion protein NP5 We introduce a sensor array based instrument capable of analyzing complex gases or vapors for quality control, such as quality of food or air. The instrument consists of a compact gas chromatograph with a short column, a preconcentrator and a small sensor array as a detector. The use of a chemical sensor array to add to the universal non-selective thermal conductivity detector (TCD) will enable peak identification and the short column, providing some separation, will eliminate the need for large sensor arrays. A short GC column with fast solid state sensors in a small dead volume detector chamber may provide a fast analysis compared to the traditional GC and electronic nose. With such hybridization of a sensor array and a mini-gc, the new instrument will combine the best features of an electronic nose and those of a mini-gc, such as, neural net software to interpret sensor array signals, speed, high sensitivity and selectivity. For evaluating the performance of the sensor array based instrument, we are hybridizing a commercial GC (MSI- 301) and an commercial electronic nose (Fox-4000). Electronic Nose 13

14 LAB_On_A_Chip Analytical instruments in a biochemical lab are shrunk on a credit-card-size Lab-On-A-Chip. Paradigm shift in biomedical analysis. MEMS micro instrumentation principle will revolutionize present concepts of biomedical analysis LAB_CD The detection chemistries are at the rim of the disc and can be read by the modified CD optics. Measurements may be absorption or fluorescent based. The centrifugal force generated in a CD-player-like instrument overcomes, depending on the rotation speed, the capillary forces in the fluidic network and moves fluid in a valve-less manner from reaction chamber to reaction chamber and eventually to a waste site. 14