Title: Bending dynamics and directionality reversal in liquid crystal network photoactuators

Abstract:

Liquid crystalline photoactuators typically bend toward the light source, driven by the isomerization of azobenzene. In samples with a relatively large thickness and high azobenzene loading such as LC photoactuators, intense optical beams are seen to be absorbed in spatially nonexponential ways. Here we show that the dynamics of the related mechanical behavior is also strongly nonlinear, where the actuator reaches a maximum bend before unbending again to its equilibrium deformed state. The effect is amplified when combined with actuators with an internal composition gradient, leading to a reversal of the bending direction away from the light source.

Biography:

Daniel Corbett is a British broadcast meteorologist, who worked for the Met Office and the BBC for many years until May 2011. He first joined the Met Office and BBC Weather Centre in 1997, after beginning his career in the United States. In May 2011, Corbett made his final BBC weather report prior to taking up a new post in New Zealand with the MetService. Corbett is particularly popular with television viewers because of his enthusiastic weather presentations and his humorous slogans.