Self-regulating photochemical Rayleigh-Bénard convection using a highly-absorbing organic photoswitch
Serena Seshadri, Luke F. Gockowski, Jae-Jun Lee, Miranda M. Sroda, Matthew E. Helgeson, Javier Read de Alaniz, Megan T. Valentine
Abstract
Abstract We identify unique features of a highly-absorbing negatively photochromic molecular switch, donor acceptor Stenhouse adduct (DASA), that enable its use for self-regulating light-activated control of fluid flow. Leveraging features of DASA’s chemical properties and solvent-dependent reaction kinetics, we demonstrate its use for photo-controlled Rayleigh-Bénard convection to generate dynamic, self-regulating flows with unparalleled fluid velocities (~mm s −1 ) simply by illuminating the fluid with visible light. The exceptional absorbance of DASAs in solution, uniquely controllable reaction kinetics and resulting spatially-confined photothermal flows demonstrate the ways in which photoswitches present exciting opportunities for their use in optofluidics applications requiring tunable flow behavior.