scholarly journals CVD grown Graphene Microfilms as a Promising Microscaled Solid Lubricant for the Lubrication of Silicon MEMS Devices

Author(s):  
Muhammad Chhattal ◽  
Abdul Ghaffar ◽  
Fayaz Ali Dharejo ◽  
Salamat Ali

Abstract Friction, wear, stiction, adhesion, and absence of suitable lubrication methods are important challenges, severely restricting and limiting the expeditious development of Microelectromechanical system (MEMS) technology. This paper aims to explore the potential of chemical vapor deposition (CVD) grown graphene microfilms for the lubrication of sliding silicon MEMS devices to reduce friction and wear problems. A novel silicon-based pin-on-disk friction-pair is designed to mimic sliding MEMS working conditions. Pure graphene-based microfilms are fabricated on the Cu substrate via a CVD method and transferred to the silicon substrate via the PMMA transfer method. To investigate microfilms' surface quality and morphology, microfilms are characterized via Raman spectroscopy, AFM, and SEM. For the tribological performance evaluation, different tribological tests were conducted using the microtribometer. Results show that microfilms remarkably reduced the friction coefficient and wear in the MEMS devices; however, microfilms' tribological performance depends on the roughness and the number of films on the specimen. This remarkable tribological performance suggests that graphene microfilms have the potential to increase the reliability and wear lifespan of MEMS devices. It is foreseeable that this lubrication method can be a step towards the expeditious industrial development of silicon MEMS devices.

2007 ◽  
Vol 129 (03) ◽  
pp. 24-29 ◽  
Author(s):  
Arthur C. Ratzel

This article discusses growing role of silicon micro-electron-mechanical systems (MEMS) technology in automotive and consumer products, telecommunications, radio-frequency applications, and medical care. The article also highlights that silicon-based MEMS devices must be constructed in clean rooms, such as one at Sandia's Microelectronics Development laboratory. According to engineers, the search for an in-depth understanding of wear mechanisms in dynamic silicon MEMS is expected to drive an ambitious wave of leading-edge research into microscale science and engineering, distinct from that which prevailed at the mesoscale. It has been found that gas damping between MEMS structures and the substrate, within the sealed package, can cause serious nonlinearities. While this doesn't lead to failure in the classic sense, it may make it harder to close a switch. On the plus side, gas damping can provide a cushion that enables a MEMS device to survive surprisingly high shock loads.


2013 ◽  
Vol 215 ◽  
pp. 141-147 ◽  
Author(s):  
Lothar Schäfer ◽  
Tino Harig ◽  
Markus Höfer ◽  
Artur Laukart ◽  
Dietmar Borchert ◽  
...  

2014 ◽  
Vol 68 (5) ◽  
pp. 629-641 ◽  
Author(s):  
Tatjana Djakov ◽  
Ivanka Popovic ◽  
Ljubinka Rajakovic

Micro-electro-mechanical systems (MEMS) are miniturized devices that can sense the environment, process and analyze information, and respond with a variety of mechanical and electrical actuators. MEMS consists of mechanical elements, sensors, actuators, electrical and electronics devices on a common silicon substrate. Micro-electro-mechanical systems are becoming a vital technology for modern society. Some of the advantages of MEMS devices are: very small size, very low power consumption, low cost, easy to integrate into systems or modify, small thermal constant, high resistance to vibration, shock and radiation, batch fabricated in large arrays, improved thermal expansion tolerance. MEMS technology is increasingly penetrating into our lives and improving quality of life, similar to what we experienced in the microelectronics revolution. Commercial opportunities for MEMS are rapidly growing in broad application areas, including biomedical, telecommunication, security, entertainment, aerospace, and more in both the consumer and industrial sectors on a global scale. As a breakthrough technology, MEMS is building synergy between previously unrelated fields such as biology and microelectronics. Many new MEMS and nanotechnology applications will emerge, expanding beyond that which is currently identified or known. MEMS are definitely technology for 21st century.


ACS Nano ◽  
2013 ◽  
Vol 8 (1) ◽  
pp. 269-274 ◽  
Author(s):  
Jin-Young Kim ◽  
Jongho Lee ◽  
Wi Hyoung Lee ◽  
Iskandar N. Kholmanov ◽  
Ji Won Suk ◽  
...  

Author(s):  
Hadi Mirzajani ◽  
Habib Badri Ghavifekr ◽  
Esmaeil Najafi Aghdam

In recent years, Microelectromechanical Systems (MEMS) technology has seen a rapid rate of evolution because of its great potential for advancing new products in a broad range of applications. The RF and microwave devices and components fabricated by this technology offer unsurpassed performance such as near-zero power consumption, high linearity, and cost effectiveness by batch fabrication in respect to their conventional counterparts. This chapter aims to give an in-depth overview of the most recently published methods of designing MEMS-based smart antennas. Before embarking into the different techniques of beam steering, the concept of smart antennas is introduced. Then, some fundamental concepts of MEMS technology such as micromachining technologies (bulk and surface micromachining) are briefly discussed. After that, a number of RF MEMS devices such as switches and phase shifters that have applications in beam steering antennas are introduced and their operating principals are completely explained. Finally, various configurations of MEMS-enabled beam steering antennas are discussed in detail.


2019 ◽  
Vol 290 ◽  
pp. 107-112
Author(s):  
Raed Abdalrheem ◽  
Fong Kwong Yam ◽  
Abdul Razak Ibrahim ◽  
Khi Poay Beh ◽  
Hwee San Lim ◽  
...  

Studying an influence of several parameters on Chemical Vapor Deposition (CVD) used for graphene synthesis is crucial to optimizing the graphene quality to be Compatible with advanced devices. The effect of different hydrogen (H2) flow-rates (0, 50, 100, 150, 200, 250, and 300 sccm) during the pre-annealing process on CVD grown graphene have been reported. This study revealed that hydrogen flow rates during annealing changed the surface roughness/smoothness of the copper substrates. For high hydrogen flow rates, the smoothing effect was increased. Furthermore, the annealed graphene samples emerged a deferent number of layers because of morphological surface changes. According to Raman D- to G-band intensity ratios (ID/IG), the graphene quality was influenced by the annealing hydrogen flowrate. The visible light transmittance values of the grown graphene samples confirmed a few number of layers (mono to seven-layer). Mostly, the samples which annealed under moderate hydrogen flow rates showed less defects intensities and higher crystallite sizes.


Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 575 ◽  
Author(s):  
Xuwen Liu ◽  
Yan Hu ◽  
Hai Wei ◽  
Bingwen Chen ◽  
Yinghua Ye ◽  
...  

Since copper azide (Cu(N3)2) has high electrostatic sensitivity and is difficult to be practically applied, silicon-based Cu(N3)2@carbon nanotubes (CNTs) composite energetic films with higher electrostatic safety were fabricated, which can be compatible with micro-electro mechanical systems (MEMS). First, a silicon-based porous alumina film was prepared by a modified two-step anodic oxidation method. Next, CNTs were grown in pores of the silicon-based porous alumina film by chemical vapor deposition. Then, copper nanoparticles were deposited in CNTs by electrochemical deposition and oxidized to Cu(N3)2 by gaseous hydrogen azide. The morphology and composition of the prepared silicon-based Cu(N3)2@CNTs energetic films were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively. The electrostatic sensitivity of the composite energetic film was tested by the Bruceton method. The thermal decomposition kinetics of the composite energetic films were studied by differential scanning calorimetry (DSC). The results show that the exothermic peak of the silicon-based Cu(N3)2@CNTs composite energetic film is at the temperature of 210.95 °C, its electrostatic sensitivity is significantly less than that of Cu(N3)2 and its 50% ignition energy is about 4.0 mJ. The energetic film shows good electric explosion characteristics and is successfully ignited by laser.


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