Development of Peristaltic Transfer System to Transport Feces in Space:Proposal of Drive Method using Air Inflow into the Transfer Channel

Abstract

Currently, human feces on the International Space Station is incinerated in the atmosphere. Because feces contain a large amount of organic matter in addition to water, the reuse of feces would require an increased amount of renewable resources. However, conventional space toilets are not designed for reusing feces. One of the reasons for this is that it is difficult to transport an intermittent supply like feces. Therefore, in this study, influenced by the peristaltic movement of the intestinal tract of living organisms, we developed a device that can transport feces at low energy consumption. The device consists of multiple pump units driven by low air pressure. By applying air pressure to each unit in turn, the pumps are controlled to close and release, which reproduces the peristaltic motion for transfer. Furthermore, the transfer rate is improved by combining the air inflow with the transfer channel and water addition.