Researchers have created a synthetic "tree" - a centimeter-sized
hydrogel with nanopores that can pull water just like real trees
pull moisture up their tall trunks. Optical micrograph image of
a synthetic tree. Credit: Tobias Wheeler.The scientists, led by
Abraham Stroock of Cornell University, explained that this
process is called "transpiration." Getting water to overcome the
force of gravity and move upward to the top of a tree requires a
lot of energy. It's also a large factor in determining the
maximum height of a tree - after it reaches a certain height, it
just can't pull water any higher. By simulating transpiration in
the lab, the researchers show that the process is purely
physical, and requires no biological energy. Understanding how
the process works could allow researchers to use it for several
human applications. In nature, real trees have long strands of
transport tissue in their wood called xylum. When water
evaporates from the upper leaves of the tree into the
atmosphere, the xylum experienc