“Because the raw materials are widely available and the fabrication processes are simple, one could imagine involving communities in procuring, fabricating, and distributing xylem filters,” Rohit Karnik told MIT News. “For places where the only option has been to drink unfiltered water, we expect xylem filters would improve health, and make water drinkable,” said Karnik, a professor of mechanical engineering at MIT. While developing their prototype, researchers ran into two problems. RELATED Many household drinking water filters fail to totally remove PFAS The xylem sieves dry out easily in storage, sticking to the walls of the filter and slowing water filtration. The sieves also gum up after being used multiple times. Researchers were able to solve the problem by soaking the sapwood cross-sections in warm water and then dipping them in ethanol. After being allowed to dry, the filters proved much more durable. In real-world tests around the MIT campus, the filters removed 99 percent of bacteria contaminants such as E. coli and rotavirus, matching the performance of commercial filters.