The relation between the electrical property and the material microstructure of InSb grown on Si utilizing electron beam evaporation technology has been investigated. The improvement of the InSb electrical property with controlling annealing environment after post annealing is demonstrated. The crystal structure of InSb thin films were characterized with X-ray diffraction (XRD) and the surface morphology was examined by scanning electron microscope (SEM). The composition of InSb films was analyzed by electron probe microscope analysis (EPMA) and the mobility of InSb films were measured by Hall measurement. Finally, the grain size and texture of InSb films microstructure were studied by transmission electron microscope (TEM). The films were grown with different In/Sb flux ratio by controlling electron energy during electron evaporation. The results show that the poly-InSb films were formed due to large lattice difference between Si and InSb . The InSb films which had higher In concentration behave higher mobility. The highest mobility of the as-grown film is around 12000(cm2/Vs). The mobility of InSb can be improved to 26000 (cm2/Vs) by added extra Sb source annealed at 500¢J for 5 hours in an sealed ampoule. The extra Sb which dissolved with the existed In droplet in the film and adjust the composition ratio of In/Sb closing to 1:1. Besides, the post-annealing process provides the InSb film to gain much better texture. Both these two factors contribute to improve the electrical property of InSb films.

Direct Write (DW) defines an emerging group of technologies that allow the printing of electronic and other functional components out of vacuum, directly onto conformal surfaces. Both ink-jet and nozzle deposition technologies, which are seen to be complementary for the wide range of materials and processing required by industry, are employed in this project.Silver neodecanoate salt is sensitive to both light source, including ultra violet light (UV) and heat source, and is a good inkjet printing precursor when dissolved in xylene. We have studied the electrical properties of inkjet printed silver samples, derived from silver neodecanoate ink, and investigated the influence of UV treatment before thermal curing the silver samples. UV exposure at room temperature is believed to control the nucleation of silver particles. In addition we have studied the influence of thermal pre-treatment on the printed samples. This pre-treatment is thought to assist the neodecanoate precursor to form a uniform distribution of silver nanoparticles. The influence of UV exposure, thermal pre-treatment and the thermal curing conditions on subsequent track microstructure, and its influence on electrical resistivity is reported for glass substrates. Furthermore, a series of extruding experimental at different nozzle offset and pumping pressure settings are conducted based on the rheological property of silicone oil and silver paste to find the ideal condition for producing continuous tracks with good shape. These findings are used to simulate a computer model for further applications.

Carbon nanofibers (CNFs) used as nano-scale reinforcement have been extensively studied since they are capable of improving the physical and mechanical properties of conventional fiber reinforced polymer composites. However, the properties of CNFs are far away from being fully utilized in the composites due to processing challenges including the dispersion of CNFs and the viscosity increase of polymer matrix. To overcome these issues, a unique approach was developed by making carbon nanopaper sheet through the filtration of well-dispersed carbon nanofibers under controlled processing conditions, and integrating carbon nanopaper sheets into composite laminates using autoclave process and resin transfer molding (RTM). This research aims to fundamentally study the processing-structure-property-performance relationship of carbon nanopaper-based nanocomposites multifunctional applications: a) Vibrational damping. Carbon nanofibers with extremely high aspect ratios and low density present an ideal candidate as vibrational damping material; specifically, the large specific area and aspect ratio of carbon nanofibers promote significant interfacial friction between carbon nanofiber and polymer matrix, causing higher energy dissipation in the matrix. Polymer composites with the reinforcement of carbon nanofibers in the form of a paper sheet have shown significant vibration damping improvement with a damping ratio increase of 300% in the nanocomposites. b) Wear resistance. In response to the iv observed increase in toughness of the nanocomposites, tribological properties of the nanocomposite coated with carbon nanofiber/ceramic particles hybrid paper have been studied. Due to high strength and toughness, carbon nanofibers can act as microcrack reducer; additionally, the composites coated with such hybrid nanopaper of carbon nanofiber and ceramic particles shown an improvement of reducing coefficient of friction (COF) and wear rate. c) High electrical conductivity. A highly conductive coating material was developed and applied on the surface of the composites for the electromagnetic interference shielding and lightning strike protection. To increase the conductivity of the carbon nanofiber paper, carbon nanofibers were modified with nickel nanostrands. d) Electrical actuation of SMP composites. Compared with other methods of SMP actuation, the use of electricity to induce the shape-memory effect of SMP is desirable due to the controllability and effectiveness. The electrical conductivity of carbon fiber reinforced SMP composites can be significantly improved by incorporating CNFs and CNF paper into them. A vision-based system was designed to control the deflection angle of SMP composites to desired values. The funding support from National Science Foundation and FAA Center of Excellence for Commercial Space Transportation (FAA COE CST) is acknowledged.