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The effect of excimer laser annealing on the formation of luminescent nanocrystal Si ͑nc-Si͒ embedded in Si/SiO 2 superlattice is investigated. An amorphous Si/SiO 2 superlattice consisting of 20 periods of 2 nm thin Si layers and 5 nm thin SiO 2 layers was deposited on Si using electron cyclotron resonance plasma-enhanced chemical vapor deposition. Excimer laser annealing alone did not result in any nc-Si luminescence even at an energy density sufficient to melt the Si layers. However, if the nc-Si is preformed by a thermal anneal, subsequent excimer laser annealing will result in a threefold increase of the nc-Si luminescence intensity. The temperature dependence of the nc-Si luminescence spectrum, lifetime, and intensity indicates that excimer laser annealing activates luminescent nc-Si by removing defects and amorphous regions in thermally crystallized Si layers without significant changes in the size or shape of nc-Si.

In these days, various researches for biomedical application of robots have been carried out. Particularly, robotic manipulation of the biological cells has been studied by many researchers. Usually, most of the biological cell's shape is sphere. Commercial biological manipulation systems have been utilized the 2-Dimensional (called 2D hereafter) images through the optical microscopes only. Moreover, manipulation of the biological cells mainly depends on the subjective viewpoint of an operator. Due to these reasons, there exist lots of problems such as slippery and destruction of the cell membrane and damage of the pipette tip etc. In order to overcome the problems, we have proposed a vision-guided biological cell manipulation system. The newly proposed manipulation system makes use of vision and graphic techniques. Through the proposed procedures, an operator can inject the biological cell scientifically and objectively. Also, the proposed manipulation system can measure the contact force occurred at injection of a biological cell. It can be transmitted a measured force to the operator by the proposed haptic device. Consequently, the proposed manipulation system could safely handle the biological cells without any damage. This paper presents the introduction of our vision-guided manipulation techniques and the concept of the contact force sensing. Through a series of experiments the proposed vision-guided manipulation system shows the possibility of application for precision manipulation of the biological cell such as DNA.

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