Space Experiment on 3-Dimensioal Photonic Crystal Growth and Its Apparatus

An experimental apparatus for growing colloidal crystal under microgravity conditions in the International Space Station (ISS) was developed. The apparatus was designed so that all experimental steps proceeded automatically with the use of a sequential controller unit. The crystal growth cell (CGC) in which the ionic condition of colloidal dispersion medium was gradually changed with time by diffusing ions through barrier gel was designed and fabricated with polymethylmethacrylate (PMMA). The grown colloidal crystal was immobilized by photoinitiated polymerization to form polymer gel using a commercially available near-ultraviolet (UV) light-emitting diode (LED). The apparatus was proven to work well for a one month mission.