"Lotus Leaf Effect” is a cart demo that demonstrates how nature inspires nanotechnology by sharing how nanoscale features on a surface can influence how a material behaves at the macroscale. Visitors learn that lotus leaves (and many other plant leaves) are self cleaning and repel water, due to nanoscale features on the leaves. During the program, visitors compare how water interacts with regular lettuce and leaves that exhibit the lotus effect by dropping water onto the different types of leaves.
Nonpolar molecules that repel the water molecules are said to be hydrophobic; molecules forming ionic or a hydrogen bond with the water molecule are said to be hydrophilic. This property of water was important for the evolution of life. Hydrophobic interaction plays the most critical roles in the formation of the lipid bilayer of the cell membrane and the folding of proteins and nucleic acids; therefore, hydrophobic interaction is the foundation for the existence of life.
Purpose of the lesson is to: • Explore the properties of molecular bonding • Introduce students to the engineering of hydrophobic surface. • Demonstrate the concepts of hydrophobic and hydrophilic behavior.
This activity developed by NNIN explores how nanotechnology can be used to change the properties of a copper surface so that it either attracts or repels water. It is appropriate for middle school and high school students.