A new liquid membrane traps small particles and substances while letting larger objects pass through (Sci. Adv. 2018, DOI: 10.1126/sciadv.aat3276). The counterintuitive filter (shown trapping small glass beads and letting a larger one pass through), designed by a team at Pennsylvania State University, takes advantage of soap films’ self-healing properties, and with a little chemical help, it can last hours before rupturing. Researchers say the films might one day facilitate cleaner surgeries, less-smelly waterless toilets, and new pest control techniques.