What if you could pull drinking water straight from the air in minutes, not hours? This ultrasonic system could change how water reaches dry communities.
Communities with little or no reliable drinking water often look to the air as their only source of moisture. Even dry regions hold some humidity, but collecting that water fast enough has been the main barrier. Most atmospheric water-harvesting systems depend on sunlight to heat a material and release the trapped water, which means people may wait hours or days for a cycle.
Researchers at MIT are trying to solve that delay. Instead of waiting for heat, their system uses ultrasonic vibrations to shake water loose from the material that absorbed it. This method recovers water within minutes, making it useful for places that need many collection cycles each day.
The device works by sending high-frequency vibrations into a sorbent—materials that pull moisture from the air. These vibrations match the frequency needed to break the weak bonds that keep water molecules stuck to the surface. Once freed, droplets fall through nozzles into collection containers.
To support use in remote areas, the setup depends on a small power source. A solar cell can provide the needed energy and can also sense when the sorbent is full. This lets the system switch on automatically, release the collected water, and start absorbing again.
The team first assumed the material would absorb moisture at night and release it under heat, but materials that capture water strongly tend to hold onto it for too long. Experience with ultrasound from earlier work led the group to test whether vibrations could break these bonds faster. Tests showed the method to be about 45 times more efficient than solar heating.
At the center of the device is an ultrasonic actuator: a ceramic ring that vibrates when voltage is applied. Around it is a ring with nozzles that guide released droplets. In trials, saturated samples were placed on the actuator and dried within minutes.
Because the approach works with many sorbent materials, it can scale into systems. One option is a window-sized panel that absorbs moisture fast, paired with an actuator powered by short bursts of solar energy. With rapid cycling, such a system could collect more water per day than heat-based designs.
