Microelectromechanical Systems (MEMS) are systems that are designed on a micro metre scale and have become more popular as the demand for devices to get smaller has increased. The main uses of these systems are for sensors, such as accelerometers and gyroscopes and other such devices like microscopy and inkjet nozzles for example. There are many materials that can be used for MEMS as the cost of the material is almost eradicated due to the micro size of the systems being produced. This brings materials such as gold, platinum and diamond can be used, as these materials have some properties which are very desirable for a MEM systems. The most common material that is currently used in MEMS is silicon and silicon based compounds as they possess many good properties for MEMS production. Most of the materials chosen for MEMS are semiconductor materials Figure 1 shows the properties of commonly used materials.
Now that the important have been shown we can now compare the values that the current materials and diamond have to examine where diamond would be a suitable material to use.
Diamond is a material that has been closely looked at over recent years as a lot of its properties are desirable in mechanicals systems. Because of these diamond is a leading material for MEMS applications in harsh conditions , as it one of the hardest natural materials. As Figure 2 shows both amorphous and crystalline diamond possess much higher elastic moduli and hardness properties than most other MEMS manufacturing materials. This means that diamond is a good material choice for high-wear environments.
The elastic modulus of even amorphous diamond is around 800 GPa which is already much higher than any other MEMS material that is currently ...
... middle of paper ...
...C will provide a chemically inert surface in the same environments in which SiC would be affected.
The large electronic bandgap (around 5.5eV) is well suited for stable high temperature applications. This is because as the temperature of the system increases the bandgap decreases, so because of the large starting value of diamond the band gap will still be wider than that of silicon and other such substances at high temperatures. This bandgap can be linked into the a corresponding wavelength of 225nm which means that diamonds can only absorb the far end of ultraviolet and vacuum ultraviolet (VUV) radiation. This leads to DLC films being considered as solar insensitive which allows them to absorb high VUV intensities while remaining reliable throughout. This allows them to be used in laser power monitors, for UV detection in the next generation of photolithography .
Valuing a diamond is a highly skilled task thus not traded on world frequently. (Valued on the basis of four criteria- 4C s carat clarity color and cut)
There is big deal of interest in silicon carbide (SiC) as an electronic material for high-voltage, high-power and high temperature applications. In this thesis, characteristics of Double gate vertical metal semiconductor field effect transistors (MESFET) fabricated on N/N+ 3C-SiC grown on N+ Si substrate are reported. The most intriguing electronic property of silicon carbide is that it is the only semiconductor material other than silicon that can have electronically passivated surface to industrial standards. The surface passivation is the main reason for the dominance of silicon but, in addition to that, silicon carbide has superior bulk properties. This combination of factors raises the question whether silicon carbide can play a role in main stream electronics (integrated-circuit based complex systems). After analysis of both technical and commercial factors and challenges leads to a conclusion that developing a silicon-carbide film on silicon wafers is the most promising way for silicon carbide enter the mainstream electronics. SiC MESFET shows great promise in high power/temperature operations when compared to Si counter parts. The simulations were performed on ATLAS (SILVACO) software, and results are presented.
It’s hard to imagine that a mineral could be fueling wars and funding corrupt governments. This mineral can be smuggled undetected across countries in a coat pocket, then be sold for vast amounts of money. This mineral is used in power tools, parts of x-ray machines, and microchips but mostly jewelry. Once considered the ultimate symbol of love, the diamond has a darker story. "Blood" diamonds or "conflict" diamonds are those mined, polished, or traded in areas of the world where the rule of law does not exist. They often originate in war-torn countries like Liberia, Sierra Leone, Angola, and Côte d'Ivoire were rebels use these gems to fund genocide or other questionable objectives. Even with a system known as the Kimberly process which tracks diamonds to prevent trade of these illicit gems, infractions continue as the process is seriously flawed. The continuation of the blood diamond trade is inhuman, and unethical, and in order to cease this illicit trade further action to redefine a conflict diamond, as well as reform to the diamond certification prosess is nessasary.
Hughes Microelectronics is a company that were found to have unethical practices during the 1980’s when handling government contracts. This was brought to light by two whistleblowers that worked for the company at the time. The purpose of this is to review four main questions concerning the situation and how it was handled ethically by the whistleblower. The first and second parts will be fairly similar what were the responsibilities of the company itself, what were the responsibilities of the main whistleblower Margaret Goodearl. Next, the conflict between the two parties will be examined and also whether or not the situation was handled ethically. Lastly the question of whether or not whistleblowing is the most ethical solution
To begin diamonds are can be found all over the world including countries like, Botswana, Canada, Namibia, Russia, South Africa, Australia, and Tanzania. Yet, diamonds are still quite rare and are only found from two dominant deposits. The primary deposits often consist of diamond-bearing “pipes” of volcanic rock called kimberlite. Deep within th...
This paper aims to discuss various optoelectronic devices; their structure, materials, theory of operation, merit properties and characteristics that recommends them for various applications.
One very important piece of information is that gemstones and crystals are grown during the cooling, formative stages of Earth’s development and so it has lead me to the conclusion that they are gifts from nature. According to physics, gemstones and crystals consist of natural balances and solid sta...
Current systems are limited by the capability of sensors and actuators, as these are bulkier and less reliable than the microelectronic circuit. In a MEM system the sensors act as the ‘eyes’ and gather data about the environment. The microelectronic circuit, which is the ‘brain’, processes the data and accordingly controls the mechanical systems, the ‘arms’ of the MEMS, to modify the environment suitably. The electronics on the MEMS are manufactured using IC techniques while micro machining techniques are used to produce the mechanical and electromechanical parts.
Santarossa, B. (2004, January 13). Diamonds: Adding lustre to the Canadian economy. Retrieved November 06, 2017, from https://www.statcan.gc.ca/pub/11-621-m/11-621-m2004008-eng.htm
iii. India dominates the world’s cut and polished diamonds (CPD) market. In value terms, the country accounts for approximately 55 percent of global polished diamond market and nearly 9 percent of the jewellery market. According to GJEPC's provisional estimate, cut and polished diamonds registered 19.06 percent growth in exports at US$ 7.11 mn.
During impact most of the impact energy in the test specimen is absorbed as plastic deformation when the test specimen yields. Temperature and strain rate effect the yield behaviour and ductility of the material and hence affect the impact energy. Materials that behave this way usually have body-centred cube crystal structures and where lowering the temperature reduces the materials ductility.
MEMS is known as Micro Electro Mechanical System. It is also known as micro system technology (MST) in Europe and micro system in Japan. It is process technology used to generate micro level integrated system or devices that have combination of mechanical and electrical components. Generalized definition of MEMS can be given as “It is device where micro sensor and mechanical parts (Actuators) along with signal processing circuitry are combined on very tiny piece of silicon.” MEMS components generally have micron level dimensioned part, with a moving element which may be solid mechanics type or may fluid one, integrated with some electronic circuit. MEMS is produced using lithography and etching techniques. Besides silicon as substrate other materials like, quartz, glass and plastic are also used as substrate in MEMS devices [1]. Many machines can be built at the same time on the surface of the wafer, without any assembly that is real power of MEMS technology.
Microcontroller can be considered as a small size of computer on a chip. Because it consists of processor, random access memory (RAM), read-only memory (ROM) and input/output peripherals. Microcontroller is also named as embedded controllers, since it is part of an embedded system. According to Blacharski (2003) microcontroller defines as “an integrated chip that is often part of an embedded system”. The purpose of develop microcontroller is to evolve the performance and efficiency a machine. Microcontroller can execute itself without the any support from external. Now a day, we can see that there are appliances in everywhere which is developed by microcontroller. For instance, aircraft, vehicle engines, microwaves, fuel injection system, robots, and so on.
Grundmann, Marius. Physics of Semiconductors: An Introduction Including Devices and Nanophysics. New York: Springer, 2006. Print.
As a graduate student, I will undertake research and coursework in Electrical Engineering to enhance my competencies in this field. I intend to complete my master's degree in order to pursue my doctorate. The research that I am most interested in pursuing at Northeastern University surrounds the optical properties of MEMS devices, and the development of substrate-based fast electro-optical interfaces. My interest in this area stems from my undergraduate study in MEMs development for tri-axial accelerometers.