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An atmospheric pressure plasma based printer is described as an alternative to conventional techniques including inkjet printing. The approach is demonstrated to be capable of printing various nanomaterials, and adjusting the plasma parameters, carrier gas flows and the physical parameters of the inks or nanomaterial suspensions can optimize the print quality. Raman analysis was used to characterize the oxide materials and carbon nanotubes printed using this technique, revealing high quality prints. The printed carbon nanotubes were used in a gas sensor chip and shown to provide good ammonia detection capability.

Electrical conduction in undoped ultrananocrystalline diamond thin films and its dependence on chemical composition and crystalline structure Diamond films are prepared by microwave plasma-enhanced chemical-vapor deposition on Si ͑100͒ substrates using the H 2 -Ar-CH 4 gases. Raman scattering data, including the peak position, intensity, area, and width, are analyzed in depth and used to obtain the sp 3 -and sp 2 -bonded carbon contents and the nature of internal stresses in the films. Polarization behavior of the Raman peaks is analyzed to assess its role on the quantitative analysis of the diamond films, which suggested that the 1150 cm −1 Raman peak in nanocrystalline diamond films could be attributed to sp 2 -bonded carbon. The role of the H 2 / Ar content in the gas mixture and substrate temperature on the characteristics of the diamond film is studied. Thickness and grain size of diamond films are also determined by scanning electron microscopy and related to the deposition conditions and Raman results. Deposition conditions, which led to highest sp 3 -bonded carbon content and growth rate, are identified.