抄録
We have been investigating how to use protists as living micromachines by controlling their behaviors using their taxes. Because of the difficulty of attaching tools on protist such as Paramecium, we are now investigating the applicability of the water flea for bio-micromachine. Water fleas are small crustacean and they wear outer shells as external skeletons. Therefore, we can attach operational tools on the shell by chemical adhesion. In our former studies, we succeeded to control Daphnia magna's motion by illuminating the blue LED light to guide the swimming direction using their strong positive phototaxis. In our previous report, an operation tool was attached on a Daphnia magna, and we examined whether the operational tool enhance their ability of the object transportation or not in comparison with the previously examined transportation ability of Daphnia without tools. If we use rectangle OPS film for operational tool, it was possible to transport an object by the tool attached Daphnia. It has, however, taken longer time than the case without tools. Therefore, in this study, we change the operational tool to the polypropylene needle. We decided to install bent 2 needles on the back of the Daphnia. This tool can greatly shorten the transportation time. The maneuverability of Daphnia in this setting, however, was worse especially during pushing object. The other issue to solve for improving the Daphnia's controllability is that if the Daphnia is near the sidewall of the control pool, the LED light is difficult to irradiate. To solve this problem, we newly developed the LED rotatable type motion control pool. The Daphnia's controllability around the sidewall was improved by this new pool.
