In this paper, we propose a filter system that can selectively obtain the required substances from an artificial circulatory system. The blood circulatory system of the human body keeps us healthy. We consider this system to be useful for a robot system to maintain its condition. To realize an artificial circulatory system like a human body, it is important to deliver various substances with only a single vessel and extract only the required substances from them. We propose a method to deliver encapsulated substances. By using this method, each substance can be delivered without mixing for easy separation. We developed a filter system that can trap only the required substances without clogging based on differences in the capsule size. We conducted experiments to evaluate the separation performance of the system. We were able to obtain only the targeted substances with this system. We developed an impurity filtration system as an application of our system.