Opto-chromogenesis: Projection mapping for controlling growth, photosynthesis, and chromatic behavior of photosynthetically living organisms

Abstract We present Opto-chromogenesis, a projection-mapping framework for spatiotemporal design of growth, photosynthesis, and pigmentation in bioprinted photosynthetic living materials. Extrusion-printed hydrogels containing the cyanobacterium Fremyella diplosiphon are illuminated with calibrated patterns of light that allow us to design and regulate macroscale biomass distribution and the Complementary Chromatic Acclimation of the bacteria. The platform combines projector-based, spectrally tunable light delivery with 3Dscan guided geometric registration to impose defined photon irradiance on complex constructs. Experiments show that self-shading drives pigment shifts, lateral light intensity gradients produce differentiated growth, and targeted UV laser exposure can suppress growth, and projection mapping provides a novel method for modulating growth and color change. By outlining projector selection criteria, analysis of lab-scale growth studies and non-invasive monitoring techniques that demonstrate parallel screening of illumination conditions, the paper establishes a basis for creating a photosynthetic architectural material that can adapt its color to changing lighting condition and capture CO 2 .