Single-walled carbon nanotubes (SWNTs), synthesized using the arc-discharge method and the direct-injection-pyrolytic synthesis (DIPS) method, were dispersed in a tetrahydrofuran solution containing propylamine and used to prepare transparent and conductive thin films on PET films using an airbrush technique. The SWNTs were analyzed using vis-near infrared absorption spectroscopy, Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. The surface resistivity of the SWNT films on the substrates was measured using a four-point probe conductivity measurement. The results revealed that the purity, length, and proportion of the metallic SWNTs are important factors in decreasing the sheet resistance.

Separation of metallic single-walled carbon nanotubes (m-SWNTs) using various amines in different concentrations was investigated. The SWNTs dispersions were characterized with Vis-NIR and Raman spectrometers. The proportion of m-SWNTs toward semiconducting SWNTs increased with an increase of concentration of amines. SWNTs thin films were prepared from the SWNTs dispersion. The sheet resistance of SWNTs films decreased with an increase of proportion of m-SWNTs. We have already reported the effective dispersion of SWNTs into organic solvents by using amines as dispersant reagents [3]. Interestingly, m-SWNTs were selectively extracted into a tetrahydrofuran (THF) solution containing propylamine in high concentration. Herein, we report separation of m-SWNTs using various amines in different concentrations. The preparation of transparent and

In the present work, electromagnetic interference shielding properties of polymer composites with dispersed cup-stacked carbon nanotubes, graphite nanoparticles and carbon black were investigated. The polymer composites with carbon nanoparticles content from 1 to 5 w% were successfully prepared by the coagulation method, and composite sheets with thickness from 0.25 to 0.77 mm were formed by the hot press technique. The electromagnetic interference shielding efficiency measured in the frequency range of 8.2~12.4 GHz (X-band) of cup-stacked carbon nanotubes/polymer composite was considerably higher than that of carbon black and graphite nanoparticles polymer composites at the same contents of carbon nanoparticles, and contribution of absorption to the shielding efficiency was found to be higher than that of reflection.

Devices related to VR technology and applications using them are quite popular recently. The VR technology allows the users to perform various moving operations in the virtual space. Usually, the users use some controller devices to move in the virtual space. Since the field of vision is not linked to the physical movements of the user, only the scenes around the user changes without body movements. This mental gap between sights and bodies in the real world is said to lead VR sickness. In the previous study, we have implemented a user interface using to mitigate the VR sickness. The interface consists of a fitness device, which slides both feet to the left and right, provides moving feeling of up and down in the virtual space according to the user’s movements. In order to move forward, the users swing their arms back and forth with VR controller in both hands as if they were walking. To change direction, they swing only one arm. We have observed that this method reduces VR sickness while enhancing their immersive feeling. On the other hand, since the users’ operations are limited to gestures by legs and arms, the users cannot perform their moving operations as quick as operations using the buttons and sticks of controllers. In addition, it is hard to perform complex operations due to the nature of the fitness equipment and the acceleration of the controller held in their hands as input data. We have designed and implemented a new system that solves those problems while keeping a certain degree of immersive feeling by using a music game mat instead of fitness equipment. We have tried to extract more information from the foot movements. On the music game mat, arrows and symbols are drawn, and when the users perform stamping and apply certain pressure patterns, they can convey their wills to the system. For example, when the users want to move forward in the virtual space, they just perform stamping their right and left foot alternately on the forward-arrow symbols. The users can adjust their moving speed in the virtual space through changing the stamping frequency. If the users stamp right or left turn marks, they can change the moving directions. If the users stamp right and left initial position marks simultaneously by their feet and then release their feet after a few seconds, they can jump a certain height proportional to the stamped period. Thus, by inputting certain stamping patterns on the gaming mat, the users can perform various moving operations according to the patterns. To demonstrate the feasibility of our method, we have conducted numerical experiments on both our method and conventional methods in the same conditions. As preliminary experimental results, our method gives users more immersive feeling than conventional methods and equally excellent immersive feeling of our previous method, and to improves the response time greatly and to contribute the reduction of VR sickness as well.