John Biggins

Soft solids are found throughout biology and engineering - we eat them, sleep on them and are made out of them. Familiar examples include rubber, jelly, sponge, muscle and skin. I am interested in the mechanics of these materials: how do they deform, contort and fail? The hallmark of such soft solids is that they can deform substantially, and in response to slight and diverse stimuli. Their solid mechanics is correspondingly rich and dramatic, with many examples of spectacular shape changing phenomena for us to understand, and ultimately use in shape-shifting devices. Currently, my research in soft solids is mostly focused on two themes. Firstly, I work on liquid crystal elastomers, which are a new type of engineering material that can contract on demand - i.e. an artificial muscle. Engineers have not previously had access to such shape changing materials, and they open new vistas for soft shape-shifting machines. Secondly, I work on elastic instabilities such as wrinkling and buckling. Such instabilities are much richer in soft materials than stiff materials, as the materials can survive them, so the instabilities can be used to switch shape and impart function. For example, I have elaborated a hypothesis that the human brain folds into gyri and sulci via a mechanical wrinkling instability. More details of my research themes, and several dramatic videos, can be found at https://www.soft.eng.cam.ac.uk/research.html My research is all rooted in theory, particularly continuum mechanics, geometry and condensed matter physics. However, I also find that good theory must be done in close dialogue with experiment. Accordingly, I collaborate widely with leading experimentalists, and my group is now building our own experimental capacity.