Pierre's research asks the question: how does shape arise? Projects that he has worked on, often in close collaboration with experimentalists, include
- Inversion in Volvox: Embryos of the green alga Volvox are spherical sheets of cells that turn themselves inside out through a small hole, in much the same way as one would turn a sock inside out. A series of papers combining experiment and theory elucidates the mechanical effect of the cell shape changes underlying this inversion, and hence sheds light on the regulation of inversion.
- Shape-Shifting Droplets: Experiments show that microscopic oil droplets in soapy solution do not simply freeze under slow cooling, but flatten into a host of polygonal shapes. A simple model predicts, among other observations, the sequence of polygons observed in experiments.