Papers by Keyword: Switching Mechanism

Abstract: Based on studying the existing electric wheelchairs for disabled are not well adapted to a variety of road conditions, broken through the structure of traditional wheelchairs, a design proposal that can make electric wheelchair achieve the function of climbing stairs and walking was putted forward and a novel mechanism was designed. The mechanism can make the crawler chassis and the wheels of wheelchair switch when needed, and make the wheelchair travel freely and flexible on the ground or on the stairs. The finite element model of the mechanism was built, and the strength analysis was carried out. The strength analysis provide the theoretical basis for the prototype manufacture.

Abstract: Both a low and a high resistance stateｓ which were written by the voltage application in a local region of NiO/Pt films by using conducting atomic force microscopy (C-AFM) were observed by using scanning electron microscope (SEM) and electron probe micro analysis (EPMA). The writing regions are distinguishable as dark areas in a secondary electron image and thus can be specified without using complicated sample fabrication process to narrow down the writing regions such as the photolithography technique. In addition, the writing regions were analyzed by using energy dispersive X-ray spectroscopy (EDS) mapping. No difference between the inside and outside of the writing regions is observed for all the mapped elements including C and Rh. Here, C and Rh are the most probable candidates for contamination which affect the secondary electron image. Therefore, our results suggested that the observed change in the contrast of the secondary electron image is related to the intrinsic change in the electronic state of the NiO film and a secondary electron yield is correlated to the physical properties of the film.

Abstract: Intensive research is currently underway to exploit the highly interesting properties of nano-sized particles and organic molecules for optical, electronic and other applications. Recently, it has been shown that nano-sized particles and small organic molecules embedded in polymer matrices can be used to realise memory devices. Such memory devices are simple to fabricate via the spin-on technique. This work presents an attempt to use sea salt, embedded in polyvinyl acetate, in the making of the memory devices. A polymer blend of polyvinyl acetate and sodium chloride (NaCl) was prepared in methanol and spin coated onto a glass substrate marked with thin Al tracks and a top contact was evaporated onto the blend after drying - this resulted in a metal-organic-metal (MOM) structure. The current-voltage (I-V) behaviour of MOM devices shows that the devices can be switched from a high conductivity state to a low conductivity state, by applying an external electric field - this property can be exploited to store data bits. The possible charging mechanism, based on the electric dipole formation, is presented in this work. Polymer blends of polyvinyl acetate with nano-particles of BaTiO3 are also investigated to further our understanding of charging mechanism(s).