Roughly 780 million people around the world have no access to clean drinking water. According to the World Health Organization (WHO), 3.4 million people die from water-related diseases every year. ETH student Jeremy Nussbaumer set himself the goal of making a contribution to solving this problem. Working with researchers from a group led by Wendelin Stark, head of the Functional Materials Laboratory, the 23-year-old spent a year researching a membrane filter and developing a prototype.