City University of Hong Kong
Microspacecraft/satellite is one application of MEMS in space field. The low-cost and reliable clusters of microspacecraft have more merits than a conventional spacecraft in fabrication, launch and operation. In a microspacecraft, a micropropulsion system is required for station keeping, attitude control, and orbit adjust. New silicon and ceramic solid propellant microthrusters will be presented. They have more design flexibility, higher fabrication efficiency, and better bonding quality compared to previous approaches.
Energetic materials (EMs) including propellants, explosives, and pyrotechnics have found diverse civilian and military applications. Nano EMs have improved performances in energy release, ignition, and mechanical properties than their bulk/micro counterparts. A novel nano Al and CuO nanowire based nEM (also called nano thermite composite) will be discussed, which has several advantages over previous investigations such as enhanced contact, reduced impurities, tailored dimensions, and easier integration into microsystem.
Electro-explosive initiators (EEIs) activated by electrical energy are used to initiate an explosive, burning, electrical, or mechanical train. EEIs have found numerous civilian and military applications such as triggering the inflation of airbags in automobiles, micropropulsion, arm fire/safe devices used in missiles/rockets, and many other ordnance systems. An innovative EEI is developed by integrating Al/CuO nEM with a Au/Pt/Cr micro heater on a substrate. It allows batch fabrication and high level of integration and reliability. The tested ignition power, ignition delay, ignition energy, energy output, and flame temperature are 1.16 W, 0.1~0.6 ms, 0.12~0.70 mJ, 60 mJ, and 2000 oC, respectively.
Lastly, our research on Au and TiO2 nanoparticles, 1D Ag and Cu nanorods, 2D NiO nanowalls and nanohoneycombs, 3D nano Mg and Cr will be briefly mentioned.
Some Refs: Kaili Zhang, et al, APL, vol. 92, 063123, 2008; APL, vol. 91, 113117, 2007; Nanotechnology, vol. 19, 155605, 2008; Nanotechnology, vol. 18, 275607, 2007; JMEMS (Accepted in 2008); JMEMS, vol. 16, 919, 2007.
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Event: |
MEEM Seminar 0708_033 |
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Date: |
16 June 2008 (Monday) |
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Time: |
2:30pm |
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Venue: |
Room G4701 |
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Speaker: |
Dr. Kaili ZHANG |
Kaili Zhang received the B.S. degree in mechanical engineering in 1997 from Dong Hua University, Shanghai, China. He obtained the PhD degree in microsystems at National University of Singapore in 2006. From 2006 to 2008 he worked on nanosystems as a postdoc at Laboratory for the Analysis and Architecture of Systems, French National Center for Scientific Research (LAAS-CNRS). He is now working on carbon nanotubes in micro and nanosystems group at Swiss Federal Institute of Technology (ETH-Zurich). His current research interests are in nanoenergetic materials, nanometals, nanometal oxides, carbon nano tubes, micropropulsion, microigniter, solar cell, fuel cell, and hydrogen storage.
Enquiry: MEEM General Office (Tel: 2788 8420 Email: mego@cityu.edu.hk )