Mr Yoon told MIT News in April that portable desalination units typically require high pressure pumps to push salt water through the necessary filters, compromising the energy efficiency of the device. However, that’s not true with the new device, which does not rely on high pressure pumps and only requires as much power as a cell phone charger to operate.

Instead of using pumps, the MIT device relies on a process called ion concentration polarization in which an electrical field is applied to membranes placed around the water that can repel positively and negatively charged particles like salt as they flow by. The device also then uses a second process called electrodialysis to remove any remaining salt from the water that passes through it.