The Biological Design Unit investigates 'How' and 'Why' living organisms have the shape and body plan they have. Their research is highly interdisciplinary and collaborative, incorporating methods and concepts from multiple disciplines of biology and physical and engineering sciences, such as cell and developmental biology, evolutionary biology, biomechanics, and synthetic biology. In particular, the unit studies the design principles of biological structure and architecture, such as slender bodies, at multi-scales from cells to organ systems (e.g., hairs, fibers, shoots). They test key function-determining design features in different environmental conditions, via reconstruction by fabricating artificial models and bio-fabricating with synthetic biology.