Fecalphobic oil-coated femtosecond-laser-processed PTFE surface

Abstract

Water, sanitation, and hygiene (WASH) investments have become crucial not only to prevent and recover from pandemics and local outbreaks but also to prevent the spread of antimicrobial resistance. However, over 2 billion people worldwide still have access to even poor sanitation, which devastates public health and social and economic development. In addition, inadequate sanitation can cause contamination to drinking water sources where exist insufficient protection, exacerbating clean water scarcity. Here, we introduce a femtosecond laser processing technology combined with silicone oil coating to prepare a slippery surface that can repel feces, named the fecalphobic surface. Compared to a flat surface, the fecalphobic surface requires only a quarter amount of water (on average) or even no water to remove sticky viscoelastic solid-like fecal simulants. Besides, various liquids will slide off this surface. Moreover, the simulant slides off the fecalphobic surface much faster than off an untreated one, approximately 3–26 times faster depending on their weight. The mechanism of the fast sliding of fecal simulants is explained. Moreover, the fecalphobic surface is installed on a latrine prototype that integrates an automatic trap door and a urine-feces separator for improved sanitation solution.