Current activity in, and future prospects for, the incorporation of mechanochemically active functional groups ("mechanophores") into polymers is reviewed. This area of research is treated in the context of two categories. The first category is the development of new chemistry in the service of material science, through the design and synthesis of mechanophores to provide stress-sensing and/or stress-responsive elements in materials. The second category is the reverse - the development of new material architectures that efficiently transmit macroscopic forces to targeted molecules in order to generate chemical reactivity that is inaccessible by other means. © 2011 The Royal Society of Chemistry.