MEEN 489-500 Nanoscale Issues in Manufacturing Lithography Lecture 2: MEMS 1-Lithography 3
Take-home Exercise Design a process which allows for a micrometer sized gear on a surface Freely rotating around a rigid axis 2-Lithography 2
MEMS (MICRO-ELECTRO MECHANICAL SYSTEMS) What are MEMS Electronics vs. Micromechanical components MEMS Applications Fabricating MEMS Advantages of MEMS Manufacturing Current Challenges http://www.mems-exchange.org 3-Lithography 2
How small micrometer is? 1 µm = 10-6 meters = 1000 nm Average diameter of a human hair = 70 micrometer Component of MEMS may be <1 µm http://www.vs.afrl.af.mil/factsheets/mems.html/mems2.gif 4-Lithography 2
More Images of MEMS Courtesy Sandia National Laboratories, SUMMiTTM Technologies, www.mems.sandia.gov 5-Lithography 2
What are MEMS? Micro-Electro-Mechanical Systems Integration of: - mechanical elements - sensors - actuators - electronics Created on a common silicon substrate Using Microfabrication technology 6-Lithography 2
Electronics vs. Micromechanical components Electronics: - fabricated using integrated circuit (IC) process sequences Micromechanical components: - fabricated using compatible "micromachining" processes http://www.memsnet.org/mems/mems-image-1.jpeg 7-Lithography 2
Typical MEMS Applications Biotechnology: - Scanning Tunneling Microscopes (STMs( STMs) ) to detect hazardous chemical and biological agents Communications using RF-MEMS technology: - Improvement on electrical components (inductors, tunable capacitors, etc.) - Huge potential in various microwave circuits with mechanical switch Accelerometers: - Better accelerometers for crash air-bag systems 8-Lithography 2
Application: Pawl Drive & Optical Switch 9-Lithography 2
Application: Optical safe switch http://www.memx.com 10-Lithography 2
Application: Mirror Array 11-Lithography 2
Application: Leaf Springs for µmotor 12-Lithography 2
Application: Electrostatic Torque Drive 13-Lithography 2
Application: Fun with Gears and Dust Mites 14-Lithography 2
Application: 3 Piston Steam Engine 15-Lithography 2
Application: Thumper http://www.memx.com 16-Lithography 2
Application: Stepper Motor Macroscale motors are magnetic Micromotors use electrostatics http://engineering.dartmouth.edu/other/microeng/courses/es65/images/henning6.gif ges/henning6.gif 17-Lithography 2
Fabricating MEMS MEMS have made electrically-driven motors smaller than the diameter of a human hair MEMS technology is NOT just about size Not about making things out of silicon... http://www.memsnet.org/mems/fabrication.html/mems-image-2 18-Lithography 2
Fabricating MEMS A A great way of making complex electromechanical systems uses batch fabrication techniques similar to those used for integrated circuits Combining electromechanical elements together with electronics http://www.mems-exchange.org 19-Lithography 2
Advantages of MEMS Manufacturing Extremely diverse technology - significant effect on commercial and military product, e.g. flaps Already used for in-dwelling blood pressure monitoring, active suspension systems for automobiles, etc. 20-Lithography 2
Advantages of MEMS Manufacturing Blurs the distinction between complex mechanical systems and integrated circuit electronics Complex electromechanical systems to be manufactured using batch fabrication techniques, increasing the reliability of the sensors and actuators to equal that of integrated circuits Cost is predicted to be much lower than macrodevices 21-Lithography 2
Current Challenges In most companies: - Limited options for prototyping/manufacturing devices - No capability/expertise in microfabrication technology - High cost for own fabrication facilities 22-Lithography 2
Current Challenges Packaging: - Currently in primitive state - MEMS packaging is more challenging than IC packaging - Most expensive and time consuming task in the overall MEMS product development 23-Lithography 2
Current Challenges Fabrication Knowledge Required: - Must have high level of fabrication knowledge in order to create a successful design - MEMS device design needs to be separated from the complexities of the process sequence 24-Lithography 2