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

嵌入式微芯片设计正在普及到我们的日常生活中，并继续在我们国家的安全和健康中发挥着重要的作用。根据定义，嵌入式设计是一种包含计算机处理器(微处理器)的电子系统，但我们并不认为它们是计算机，因为计算机被隐藏或“嵌入”在产品中。美国的家庭平均拥有30到40个微处理器，但其中只有45%的家庭拥有台式计算机。其余的这些微处理器被嵌入到家用电器中。嵌入式系统的例子包括汽车中的计算机控制的燃油喷射器，烤面包机和洗衣机中的控制机构，无人驾驶航天器的遥控器，或者用于监测人体内非法药物或危险化学品的生物流体的液体传感设备。这些设备的微小尺寸使它们非常有吸引力，因为它们重量轻，携带方便。在健康应用中，这些设备可以注射到人体内，用于诊断和监测附近没有医院的偏远地区的患者。它们甚至可以减少昂贵的住院时间，方法是在没有任何人为干预的情况下，按时间表为患者分配正确的药物。嵌入式系统的应用可以使用许多不同的科学原理来设计，例如在一个产品中都有化学、生物、光学、电子和机械工程理论。使用这种多学科设计技术的单个微芯片被称为“MEMS”，即微型机电设备。因此，MEMS的多学科性质要求许多专家一起工作，并了解他或她的设计部分将如何与设计的所有其他部分相互作用和相互联系。这给生产低成本、可靠和安全的产品带来了许多问题。以监测人体内非法药物或危险化学品的MEMS设备为例。这为设备的运行提供了一个非常恶劣的环境，因为这些设备容易受到腐蚀和污染。如果不对其保质期和使用寿命进行测试，该设备可能会造成伤害。在防御系统中，导弹上的MEMS芯片允许导弹与指挥中心通信，并报告导弹的准确速度和位置坐标。拥有这类功能可以在飞行中修改导弹的弹道，以提供对目标的精确定位，并将平民伤亡降至最低。如果设备出现故障，可能会导致行为反复无常，可能会导致灾难性的后果。从制造的角度来看，发展MEMS的普遍问题是技术风险和生产成本。如果不开发用于寿命测试的良好的重复性和可靠性测试，MEMS器件的生产成本可能会高得令人望而却步，对消费产品来说也是不现实的。总之，开发这项技术的主要问题包括：(A)设计的跨学科性质需要许多不同的设计师技能集，他们了解自己的设计部分将如何与设计的所有其他部分相互作用和互连。(B)开发可靠性和安全性的测试方法；和(C)开发可重复和可靠的低成本制造方法，以使最终产品负担得起。研究工作将集中在开发一种模拟方法，以帮助设计师开发和执行跨多个科学和工程学科的MEMS设计的稳健测试。考虑一个电子控制和通信系统来控制和修正导弹在飞行中的飞行路线。电子设计由电气工程师实施，而跟踪导弹位置的传感器和移动导弹机翼的致动器则由机械工程师开发。这两个设计连接的边界是一个已知的错误来源，这是因为设计规程之间缺乏理解。使用模拟允许在对实际物理硬件进行任何支出之前对设计进行低成本的实验；然而，模拟CAD工具必须跨越许多科学和工程学科才能有效。这对今天的MEMS芯片设计者来说是一个长期存在的问题。研究人员正在开发的模拟器软件将能够在一个MEMS器件的软件模型上进行数千次实验。研究人员将开发一个模拟环境，允许不同的工程学科使用相同的模拟器。模拟将发现所有运行区域的灾难性条件，并在不需要几天的计算机时间或特殊的超级计算机的情况下实现这一点。这允许工程师观察相互作用造成不良状况的系统参数的因果关系。通过了解可能发生的错误类型，设计者可以在设计投入生产之前对其进行更正。最后，许多优秀的工程师被我国最近的经济形势所取代。研究团队将得到失业工程师的补充，并为他们提供再培训和重新使用工具的机会，以便他们能够成为这项关键新兴技术的贡献者。

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.