03-09-2009, 04:44 PM
The satellite industry could experience its biggest revolution since it joined the ranks of commerce, thanks to some of the smallest machines in existence. Researchers are performing experiments designed to convince the aerospace industry that microelectromechanical systems (MEMS) could open the door to low-cost, high-reliability, mass-produced satellites.
MEMS combine conventional semiconductor electronics with beams, gears, levers, switches, accelerometers, diaphragms, microfluidic thrusters, and heat controllers, all of them microscopic in size."We can do a whole new array of things with MEMS that cannot be done any other way," said Henry Helvajian, a senior scientist with Aerospace Corp., a nonprofit aerospace research and development organization in El Segundo, Calif.
Microelectromechanical Systems, or MEMS, are integrated micro devices or systems combining electrical and mechanical components. They are fabricated using integrated circuit (IC) batch processing techniques and can range in size from micrometers to millimeters. These systems can sense, control and actuate on the micro scale, and function individually or in arrays to generate effects on the macro scale.
MEMS is an enabling technology and current applications include accelerometers, pressure, chemical and flow sensors, micro-optics, optical scanners, and fluid pumps. Generally a satellite consists of battery, internal state sensors, communication systems and control units. All these can be made of MEMS so that size and cost can be considerably reduced. Also small satellites can be constructed by stacking wafers covered with MEMS and electronics components. These satellites are called 'I' Kg class satellites or Picosats. These satellites having high resistance to radiation and vibration compared to conventional devices can be mass-produced there by reducing the cost. These can be used for various space applications.
Also small satellites can be constructed by stacking wafers covered with MEMS and electronics components. These satellites are called 'I' Kg
TECHNOLOGY
Although MEMS devices are extremely small MEMS technology is not about size. Instead, MEMS is a manufacturing technology; a new way of making complex electromechanical systems using batch fabrication techniques similar to the way integrated circuits are made and making these electromechanical elements along with electronics.
Material used
The material used for manufacturing MEMS is Silicon. Silicon possesses excellent materials properties making it an attractive choice for many high-performance mechanical applications (e.g. the strength-to-weight ratio for silicon is higher than many other engineering materials allowing very high bandwidth mechanical devices to be realized).
Components of MEMS
Micro-Electro-Mechanical Systems (MEMS) is the integration of mechanical elements, sensors, actuators, and electronics on a common silicon substrate through the utilization of micro fabrication technology. MEMS is truly an enabling technology allowing the development of smart products by augmenting the computational ability of microelectronics with the perception and control capabilities of micro sensors and micro actuators
