Micro-electro-mechanical-systems (mems) and Fluid Flows

The micromachining technology that emerged in the late 1980s is able to provide micron-sized sensors and actuators. These micro transducers can be integrated with signal conditioning and processing circuitry to form micro-electromechanical systems (MEMS) that can perform real-time distributed control. This capability opens up new territory for flow control research. On the other hand, surface effects dominate the fluid flowing through these miniature mechanical devices because of the large surface-to-volume ratio in micron-scale configurations. We need to reexamine the surface forces in the momentum equation. Owing to their smallness, gas flows experience large Knudsen numbers and, therefore boundary conditions need to be modified. Besides being an enabling technology, MEMS also provides many challenges for fundamental flow-science research. ________________________