RSI Research Seminar

Join us every other Monday at noon for lunch and a 30-minute research talk, presented by Resnick Sustainability Institute Graduate Fellows and Caltech researchers funded by the Resnick Sustainability Institute. To see the full schedule of speakers, visit the RSI Research Seminar web page. Seminars currently take place in a hybrid format, both in-person (Jorgensen building first-floor conference room) and via Zoom. For more information and to get the Zoom login info, please reach out to [email protected]

Inorganic Phototropism: Biomimetic Mesosostructure Growth and Functionality

The growth of highly anisotropic, nanostructured semiconductor films were generated via a photoelectrodeposition method. The material self optimizes to maximize the light collection and thus the optical inputs determine the resulting film morphology. Here we investigated the ability of these films to mimic phototropism, a natural phenomenon where a plants out-of-plane growth is directed by its illumination source, such as in sunflowers or palm trees. The ability of these nanostructured films to mimic the phototropic growth process was investigated using both natural solar and artificial insolation. Morphological complexity was generated by combining the use of inclined illumination with a series of defined polarization and wavelength inputs which allowed variation of the feature anisotropy, in-plane and out-of-plane orientation, spacing, and periodicity. Additionally, the wetting properties of the nanostructured films were investigated to emulate the anisotropic wetting properties of structures found in rice leaves, spider silk and butterfly wings.