The result of a collaboration between artists and scientists from the Hydrodynamics Laboratory of the Ecole Polytechnique (LadHyX, Institut Polytechnique de Paris), the Light, Matter and

Interfaces laboratory (LuMIn, Université Paris-Saclay), and the Physical Chemistry Institute (ICP, Université Paris-Saclay) the Volvox project is inspired by the eponymous microscopic spherical

alga. The envelope of this freshwater alga is a biofilm connecting hundreds of independent cells. Spherical daughter colonies develop inside the sphere. To swim towards the light and feed, the movement of all the unicellular’s cells must synchronize, and the Volvox performs a dance alternating coherent movement and random reorientation. For the life sciences, Volvox represents a stage in the evolution, a step towards complexity, being a multicellular organism with mechanical and chemical communication between cells.

The Volvox installation is a metaphor for life in which the endless search for light is transposed using gold nanoparticles suspended in water. They fill glass capsules that are themselves caught in a dance that is both random and synchronized within a rotating transparent sphere. By changing the angle of observation in relation to the incidence of light, the public can experience the relativity of the notion of color, as the gold changes from blue to orange, passing through light purple, itself a complementary color to the green of the algae. This dichroism coloring effect is due to the dominant contribution of the localized surface plasmon resonance phenomenon in the nanoparticles, which affects both the absorption and scattering of light.

The sound creation uses the Volvox algae scenario as a musical form. Each Volvox induces musical sounds that envelop the audience, spectators of a series of coordinated movements that give way to the natural process of chaos.

Thomasine Giesecke, visual artist / Jean-Marc Chomaz, physicist artist @LadhyX, Ecole Polytechnique / Bruno Palpant physicist @LuMIn, Université Paris-Saclay / Tom Georgel, sound artist, in collaboration with Hynd Remita and Mireille Benoit, chemists @Institut de Chimie Physique, Université Paris-Saclay / Jean-Michel Wierniezky, Ecole Polytechnique / Claude Beghin, Maïa Menuiserie / Colin Lopez LuMIn, Université Paris-Saclay /