Aaswath Raman

2020 Hellman Fellow


Assistant Professor, Materials Science and Engineering

Project title: Multi-functional Metamaterials to Enable Passive Dew Condensation

Project description: Global water demand is expected to grow 55% by 2050, when 40% of humanity will live in regions under severe water stress. If we are to sustain 10 billion people by 2050, we urgently need to develop new ways of producing water that have minimal environmental or climate impact. To tackle this challenge, we propose to develop a new class of multi-functional, structured material that can passively generate freshwater from the atmosphere, even in the driest of climates, simply by facing the sky. The metamaterials we will develop will optimally harness a passive cooling mechanism that my lab has pioneered – radiative sky cooling – wherein sky-facing surfaces can cool themselves below the air temperature by rejecting their internal heat to outer space through a window in Earth’s atmosphere. By passively cooling itself below the dewpoint, the material will condense water vapor from the air into liquid droplets. Central to the material’s breakthrough ability to generate water from the air will be a new strategy to simultaneously optimized its thermal radiation spectrum, allowing the material to passively cool down to lower temperatures, and its surface wettability, to optimally collect and funnel away water that condenses on its surface.