A close-up photo of a water droplet, shaped in an elongated oval, pumping out a spray of tiny microdroplets from one end. Credit: Dan Daniel Water droplets might seem simple at first. But when nearing evaporation, a desperate power struggle of competing physical forces can emerge, with explosive effects. In a Proceedings of the National Academy of Sciences publication, researchers have taken a closer look at the physics of charged water droplets on frictionless surfaces, observing spontaneous jets of microdroplet emissions. Their insights may open new opportunities in nanoscale fabrication and electrospray ionization. Professor Dan Daniel, head of the Droplet and Soft Matter Unit at the Okinawa Institute of Science and Technology (OIST) says, "From raindrops to spray coatings, mass spectrometry to microfluidics, sneezes to spacecraft plumes, charged droplets can show up in a surprising wealth of settings.…