Scientists Measure What It Takes to Push a Single Atom

Just 17 piconewtons, or 60 trillionths of an ounce, is the force it takes to push a cobalt atom across a copper surface. This is one of the findings of a group of IBM scientists who have been testing a new kind of atomic force microscope (AFM), which has made the first measurements of the force required to move an individual atom.

The February 1, 2008 edition of the journal Science includes a brief article focusing on the futuristic sounding topic of Adaptive Composites. Richard Vaia and Jeffery Baur write that materials are now under development that can respond dynamically to changes in their environment. Concepts such as suppleness to squeeze through crevices, aircraft skin that regulates temperature and self-healing composites are now being studied. These ideas go beyond the idea of advanced composites and into the field of adaptive composites. This same focus in materials science are "driving the development of adaptive composites that mimic biological responsive functionality while operating in extreme environments." Today's design includes ideas of "structural efficiency" with "active functions such as sensing, energy harvesting and propulsion are added by attaching components to the structure." But changes may be on the way soon.
Currently "advanced passive material technologies such as continuous-fiber organic-matrix composites" are used in various applications. New innovations are aiming to incorporate "flexible, jointed frameworks and complex materials [that] impart active functionality at multiple length scales within the materials." This requires synthetics that combine materials that have active properties, autonomic response and "new computational tools that enable design, analysis and optimization of the collective and hierarchical dynamic character." The aerospace industry seems to be most interested in the "transformation of rigid substructure to a dynamic, articulated structure." Uses include "large-scale antennae in space and the development of morphing wings on unmanned aerial vehicles."
Other goals include "energy-efficient locomotion and concealment" which are top priorities. By mimicking organisms it is hoped that "highly deformable networks can be created from cellular materials, bistable composite laminates and bimorph strips." It is also hoped that using CNTs(carbon nanotubes) will be incorporated into mats and arrays that stress energy can be stored and recovered. From all appearances the greatest hurdle is not the lack of constituents for material composites but a real need for better and more "streamlined computational design tools that capture the properties of the many possible configurations or states." The complexity in coupling multiple active materials with evolutionary, emergent and morphogenic attributes is with not an obstacle. Indeed it remains only a challenge yet to be fulfilled. Some real challenges do include weakness at interfaces, bonding and reverse flexibility.
The contributors Vaia and Baur say that elegant outlines have been proposed in earnest since 2004. They also believe utilization of micro- and nano-robotics as well as fluidics will also contribute much to these novel adaptive materials. In these two ideas we not only face the challenge of design but also that of durability.