From Newton’s Cradle to New Materials

Chiara Daraio, Ph.D.
Aeronautics and Applied Physics
California Institute of Technology (Caltech)

The bouncing beads of Newton's cradle fascinate children and executives alike, but their symmetric dance hides complex dynamic behavior. Lift a bead on one side off a chain of a few suspended beads, let it swing back: one bead bounces off on the other side. Do the same with a long chain of beads: several beads bounce off on the other side. This represents an example of nonlinear wave dynamics, which can be exploited for a variety of engineering applications. By assembling grains in crystals or layers in composites  such  that  they  support  nonlinear  waves,  we  are  developing  new materials and devices with unique properties. We have constructed acoustic lenses that  allow  sound  to  travel  as  compact  bullets  that  can  be  used  in  medical applications, have developed new materials for absorbing explosive blasts, and are exploring new ways to test aircraft wings and railroad tracks nondestructively with the help of nonlinear waves.

Professor  Daraio’s  research  aims  at  designing  and  testing  new  materials  with unprecedented mechanical properties. She is interested in developing a physical understanding of how stress waves propagate in nonlinear, ordered and disordered solid media at length scales ranging from nanometers to meters. She received her  undergraduate degree in Mechanical Engineering from the Universita’ di Ancona, Italy (2001). She received her M.S. (2003) and Ph.D. degrees (2006) in Materials Science and Engineering from the University of California, San Diego. Chiara joined the  Aeronautics  and  Applied  Physics  departments  of  the  California  Institute  of Technology (Caltech) in fall of 2006, where she now is a full professor. She won several awards. Among these, she received a Sloan Research Fellowship in 2011, she was selected as one of the Brilliant 10 by Popular Science Magazine (2010) and as an ONR Young Investigator (2010). She is a winner of the NSF CAREER award (2009) and the Richard Von Mises Prize (2008).