A Unified Simulation and Fault Environment for Mixed Signal Systems including MEMS Components

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Embedded microchip design is becoming prevalent in our daily lives and continues to play an important role in the security and health of our nation. An embedded design by definition is an electronic system that contains a computer processor (microprocessor), yet we do not think of them as computers because the computer is hidden or "embedded" in the product. Homes in the United States have an average of 30 to 40 microprocessors, yet only 45% of these homes have a desktop computer. The rest of these microprocessors are embedded in appliances. Examples of embedded systems include the computer controlled fuel injectors in automobiles, control mechanisms in toasters and washing machines, a remote control for an unmanned spacecraft, or liquid sensing devices such as those used to monitor biological fluids for illicit drugs or hazardous chemicals in the human body. The tiny size of these devices makes them very attractive because they are light and portable. In health applications, these devices can be injected into the human body and used to diagnose and monitor patients in remote areas that do not have a nearby hospital. They can even reduce expensive hospital stays by dispensing the correct amount of a drug in a patient on a time schedule without any human intervention.Applications of embedded systems can be designed using many different scientific principles such as chemical, biological, optical, electronic and mechanical engineering theory all in one product. A single microchip that uses this multiple discipline design technique is called a "MEMS", micro-electromechanical device. Thus, the multidisciplinary nature of MEMS requires that many specialists work together and understand how his or her portion of the design will interact and interconnect with all the other parts of the design. This presents a host of problems with respect to producing low-cost, reliable and safe products. Consider the MEMS device for monitoring illicit drugs or hazardous chemicals in the human body. This presents a very harsh environment for the device to operate in since these devices are subject to corrosion and contamination. The device could cause harm if its shelf-life and lifetime use properties were not tested. In defense systems, MEMS chips aboard missiles allow the missile to communicate with the command center and report the exact speed and position coordinates of the missile. Having this type of functionality allows the trajectory of the missile to be modified in flight to provide exact precision on a target and minimizes civilian casualties. If the device fails, it could cause erratic behavior that could result in catastrophic results. From the manufacturing perspective the prevalent issues for developing MEMS are the technology risk and cost of production. If good repeatability and reliability testing for life testing are not developed, the production cost of MEMS devices could be prohibitive and not practical for consumer products.In summary, the major problems with developing this technology include: (a) The interdisciplinary nature of the design requiring many different skill sets of designers that understand how his or her portion of the design will interact and interconnect with all the other portions of the design. (b) Developing testing methods for reliability and safety and (c) Developing low-cost manufacturing methods that are repeatable and reliable so that the final product is affordable. The research work will focus on developing a simulation methodology to help designers develop and perform robust testing on MEMS designs across multiple scientific and engineering disciplines. Consider an electronic control and communication system to control and correct the flight path of a missile in flight. An electrical engineer implements the electronic design, while the sensors that track the position of the missile and actuators that move the wings on the missile are developed by mechanical engineers. The boundary where these two designs connect is a known source of errors due to the lack of understanding between the design disciplines. Using simulation allows low cost experimentation on the design before any expenditure is made on real physical hardware; however, the simulation CAD tools must work across many scientific and engineering disciplines to be effective. This presents a persistent problem for today's MEMs chip designers.The simulator software being developed by the Investigators will be able to perform thousands of experiments on software models of a MEMS device. The Investigators will develop a simulation environment that allows different engineering disciplines to use the same simulator. The simulations will find catastrophic conditions over all the operating regions and achieve this without requiring days of computer time or special supercomputers. This allows an engineer to observe the cause and effect relationships of the system parameters that interacted to create an undesirable condition. By understanding the type of errors that can occur, the designer can then correct the design before it goes into production. Finally, many outstanding engineers have been displaced by our country's recent economic situation. The research team will be complemented with unemployed engineers and offer them an opportunity to retrain and re-tool so they can become contributors to this crucial emerging technology.