Experiments from the Caltech lab of Chiara Daraio, G. Bradford Jones Professor of Mechanical Engineering and Applied Physics and Heritage Medical Research Institute Investigator, have yielded a fascinating new type of matter, neither granular nor crystalline, that responds to some stresses as a fluid would and to others like a solid. The new material, known as PAM (for polycatenated architected materials) could have uses in areas ranging from helmets and other protective gear to biomedical devic