Over the next 17 months, Virginia Tech will lead a team of researchers exploring the development of a new class of materials that will use plant protein structures in an attempt to mimic biological systems.

DARPA is specifically interested in a group of hard polymers called nastic materials. In biology, nastic refers to the natural movement of plants in response to changes in their environment, such as plants that track the sunlight or that stiffen when watered. These movements are caused by changes in the water pressure inside the plant and can result in very large changes in shape. The goal of the DARPA project, administered by John Main, is to develop synthetic materials that utilize internal pressure changes to cause large shape changes.



The plan calls for the investigation of the protein structures of plants for the purpose of understanding their role in generating shape changes in natural materials. The protein structures under analysis would then be used to develop a synthetic material that incorporates properties that produce controllable shapes.



Ultimately, successful development of the nastic structure concept will provide a new class of materials based on the direct conversion of biochemical energy into mechanical work. In this manner it will provide a truly integrated “smart” material that serves as the foundation for a new generation of biologically inspired engineering systems.



In this unique program, researchers will be working with a company on the application of nastic materials to a morphing aircraft wing. This wing would dynamically change its shape and control surfaces during flight. An analogy would be a hawk that is soaring through the sky, suddenly sees its prey, and changes its shape to make a dive towards the intended victim. As the raptor changes gear to fly southward at lightening speed, it must sense what the outside forces and pressures are for its trajectory.



More here.