In today's world increasingly miniaturised electronic products, microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) sets the standards of what can be achieved with modern engineering methods. Although these devices are typically produced using techniques analogous to those found in the semiconductor industry (such as photolithography and various deposition processes) manufacturers must be acutely aware of variances caused by the large surface to volume ratio of these devices. At these scales, the normal rules of design and production begin to blur as surface effects such as electrostatics and wetting become prevalents.
The applications and research areas for MEMS range from the exotic to the everyday but they are most commonly used for a number of 'smart' technologies including:
- Fuel pressure gauges and airflow sensors
- Brake sensors
- Accelerometers for improved air bag deployment
- Actuators and cantilevers
- Micronozzles to direct spray in inkjet printers
- Navigational gyroscopes
- 'Smart dust' for the detection of environmental changes
Despite having dramatically different applications, each of these technologies share common manufacturing methods and quality control processes that necessitate for example, high-resolution light microscopy with stereomicroscopes may be used for the inspection of faults and debris; while motorized reflected light, industrial and semiconductor microscope systems may be used for a variety of general analytical techniques such as darkfield, DIC, polarizing, epi-fluorescence and double-beam interferometry.
More recently, video measuring systems have also been applied to quality control analysis in MEMS systems as they offer exceptionally high accuracy and can be easily customised to fit the specific viewing requirements of a vast range of applications.