Inspired by the pufferfish – a creature that swells its body with water when under threat – Princeton researchers have developed a new, low-cost water purification device that uses sunlight to power its filtering process.
“Sunlight is free,” said Xiaohui Xu, a presidential postdoctoral fellow in the Department of Chemical and Biological Engineering who developed the device, “and the materials to make this device are low-cost and non-toxic, so this is a cost-effective and environmentally friendly way to generate pure water.”
The device contains a gel that works by absorbing water like a sponge, at room temperature. When heated to 33 degrees Celsius or 91 degrees Fahrenheit, the gel expels water through its pores, just like a pufferfish. This process provides purified water by filtering out harmful contaminants such as petroleum and heavy metals such as lead.
“To me, the most exciting thing about this work is it can operate completely off-grid, at both large and small scales, said the device’s co-inventor Rodney Priestley, the Pomeroy and Betty Perry Smith Professor of Chemical and Biological Engineering and Princeton’s Dean of Innovation.
The researchers are currently exploring ways to make the device widely available.