Passively pumps water for days

All vegetation, including trees and plants, big and small, are the water pumps of nature. They serve the purpose of hydraulic pumps by pulling up water through their roots. This water travels throughout the entire body of the plant to the topmost leaves. The sugars produced by the leaves are then pumped back down to the roots. This whole cycle is carried out by a complex tissue structure of xylem and phloem which are bound together in parallel conduits.

Inspired by this flawless mechanism of trees, engineers at MIT along with their collaborators have developed a microfluidic device which they call as the “tree-on-a-chip.” This is a device that copies this circulatory system of trees and plants. The chip is able to pump water and sugars passively, for several days, without the need of any external pumps. The results of this experiment are published in this week’s Nature Plants.

The professor and associate department head for operations in MIT’s Department of Mechanical Engineering, Anette “Peko” Hosoi, in an interview said that this technology can be used as an actuator for small robots. It is generally time-consuming, expensive, and tough to develop pumps that facilitate movement of the small parts in robots. This innovation proves that such technology of sugar-powered pumps can be used in similar situations.

The idea of this device came from a project on hydraulic robots which worked by pumping fluids. Hosoi wanted to design a small-scale robot that could do similar work as done by the big robots. When the hydraulic pumping takes place in the trees, the more the sugar in the phloem, the more the water flows to balance the sugar-water gradient. This process is known as osmosis. As a result of the water flow, the nutrients are flushed down to the roots of the plant. To conduct the experiment, the researchers filled the xylem channels with water and the phloem channel with water and sugar. However, this has been claimed to be a big step in the small-scale robot industry. After this has been properly developed, a lot of time and money will be saved in the entire field of hydraulics for these robots. Many groups had tried to develop a similar product, but the pumping could only be sustained for a few minutes. This development is undoubtedly a very significant breakthrough. Researchers have confirmed that the device can work in a stable state for many days at a stretch.

from The Fetcham Residents Association http://fetchamresidentsassociation.org/passively-pumps-water-for-days/