Henry Sodano's Research Group

Our research goal is to develop photoresponsive shape memory polymers (SMPs) that incorporate cinnamic acid and cinnamylidene acetic acid which are able to undergo efficient photoreversible reactions when exposed to alternating wavelengths of light. The hope is that this reversible reaction will be used to actively cleave and reform covalent crosslinks to mitigate the propagation of damage though local fracture, achieve shape recovery for crack closure, and to ultimately reform crosslinks across the crack face to recover the strength of the original material.  Our current results have shown that we can produce 1200% increased toughness, recover the plastic deformation of the specimen following loading to return it back to its original dimensions and subsequently achieve 96% healing efficiency without the reformation of crosslinks in the polymer.  This work was featured live on CNN and various other news outlets.

This approach is novel in that using adaptation of the local stiffness to mitigate the propagation of damage followed by healing has not been studied in the literature; therefore this work has the potential to make significant advances in the design of autonomous structures and in the development of greater post-treatment measures concerning fractured areas. The effort from this research will ultimately provide methods to create materials that function and respond to damage; mimicking what some biological systems naturally do.

High energy density capacitors are critically important in advanced electronic devices and electric power systems that require bursts of large energy such as pace makers, defibulators, rail guns, electric vehicles and electromagnetic armor.  Our work is studying the use of nanocomposites to create ultra high energy density capacitors with particular focus on the role the morphology and orientation of the filler plays on the energy density.  Our current results have produced nanocomposites with energy density exceeding 10 J/cc, which is more than twice as large as high performance commercial materials.  Efforts to create further gains are focused on the synthesis of new high dielectric ceramic nanowires, approaches for the functionalization of the fillers to achieve improve compatibility with the polymer matrix materials and fabrication approaches to create the highest energy density capacitors available.

Experimental and numerical results over the past decade have conclusively demonstrated the effectiveness of turbulent drag reduction (up to 40%) through near-wall control schemes such as oscillating walls and traveling waves. However, these promising results have yet to lead to a suitable surface for practical application. We are developing a new near-wall turbulence control technique based on a recently developed nanowire surface, composed of vertically aligned Barium Titanate (BaTiO3) nanowires. Since BaTiO3 is a highly coupled piezoceramic, the surface can be manipulated by application of an electric field; and conversely the surface generates an electric potential in response to an applied mechanical load. We have hypothesized that actuation of the nanowire surface can produce cross-stream motion that will alter the structure of the boundary layer over the nanowire surface, resulting in modification of the wall shear stress. This hypothesis is based on recently improved understanding of the correlation between low-speed streak instability and the generation of drag-inducing streamwise vortices; suppressing these vortices at their onset by transverse motion controls within the viscous sublayer has proven extremely effective at stabilizing the low-speed streaks, leading to significant drag reduction.