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Climate change is affecting every being on the planet. The time has arrived to give a big push for harvesting renewable energy sources, thus reducing the dependencies on fossil fuels and chemical batteries. This inspired Nanotechnologists to explore energy harvesting techniques from the environment. Triboelectric nanogenerator (TENG) is one such emerging, promising, and a reliable technology to extract micropower from the abundantly available natural mechanical energy. In this study, we have addressed the durability issues of TENG using Diamond-like Carbon (DLC) films as a triboelectric surface. Our findings indicate a high potential for DLC films for TENG applications attributing to its outstanding tribological, mechanical and insulating properties. Hydrogenated DLC (H-DLC) film, Fluorinated DLC (F-DLC) film, and PTFE were used as dielectric surfaces on a rotary based sliding-TENG. The output performance of each pair differed with the sliding frequency where H-DLC/F-DLC pair produced the maximum output at a moderate frequency of 4 Hz. As the frequency was raised, H-DLC/PTFE pair exhibited the highest output at 10 Hz, equal to that of the Al/PTFE pair. The durability evaluation of DLC-TENG showed very promising outcomes producing stable output current for 2 h. This study is expected to encourage the development of DLC-based sliding-TENGs, with enhanced durability and output efficiency.

Based on the demand of extremely increased area density for magnetic data storage, the contact recording systems have been proposed, in which stronger and thinner hard coatings and lubricant films for the head disk interface (HDI) are desired. In this study, two lubrication methods, i.e., the vacuum vapor deposition and dip-coating methods are evaluated and compared in order to satisfy the demands from the HDI development. Perfluoropolyether (PFPE) is applied to the diamond-like carbon (DLC) surface. The advantage of the vacuum vapor deposition is to prevent contamination of the DLC surface from the atmosphere because of no exposed samples to the atmosphere. In contrast, the advantage of dip-coating method is to thicken the bonded layer of the PFPE by heat treatment. We discuss the adsorption mechanism between the PFPE molecules and DLC surface for each method. In addition, a simple reaction model based on the Arrhenius equation is developed and compared to the experimental results. We concluded that the reaction will be dominated by covalent bonds and hydrogen bonding. Furthermore, the reaction model can well express the experimental results. The remarkable destruction of the DLC film by the heat treatment are not seen in the samples heat treated at a temperature from 353 to 423 K while the remarkable destruction are seen in the samples treated from 423 to 473 K.

Silicon-Boron-Carbon-Nitride (SiBCN) thin films were deposited on Si (100) substrates by ECR-type ion beam sputtering at a substrate temperature of 200 ºC, and thermal stability of SiBCN films were investigated at 600 ºC, 700 ºC and 800 ºC in air. A composed Si-B-C (Si plate and B4C target) target was used for the film deposition. The composition and chemical bonding structure of the prepared films were investigated by X-ray photoelectron spectroscopy and Fourier transform infrared spectrometer. Si-N bonds increased with increasing silicon content. Surface roughness of SiBCN films decreased with increasing Si content. Hardness of SiBCN films exhibited up to 22 GPa with increasing silicon content. SiBCN films showed no changes in chemical bonds after heating at 600 ºC. Even after heating at 700 ºC, SiBCN films maintained relatively high hardness, whereas hardness of SiBCN films was quietly reduced after heating at 800 ºC. Thermal stability of SiBCN films was improved with increasing Si content.

In order to estimate the wear process of diamond-like carbon (DLC) films, a ball on disk test and a micro laser Raman spectroscopy are employed in this study. DLC films are deposited on high-speed tool steel (JIS-SKH51) surfaces by a plasma based ion implantation and deposition (PBII&D). After the ball on disk test with a steel ball (JIS-SUJ2) as an indenter, a mapping measurement using micro laser Raman spectroscopy has been accomplished against both the wear surface of the DLC films and the surface of the indenter. As a result, obvious changes in the structure of the DLC films originating from the contact interface between the substrate and the indenter are observed. This is like to be caused by the graphitization of the DLC films. On the other hand, except for the preceding descriptions, the Raman spectra are almost same to each other and there are no changes in the structure of the DLC films. This means that the effects of the sliding on the changes in the structure can be neglected. In addition, the carbon compounds and the solid solutions of carbon and iron included in the substrate and the indenter hardly influence the Raman spectra with or without sliding.