The present disclosure relates to an element for sensing strain, stress or force. The sensing element comprises a substrate, a pair of electrodes on the substrate, and a network of carbon nanotubes for sensing the strain, stress or force within a structure. The network of carbon nanotubes defines at least in part an electrical path between the electrodes of the pair, and the electrical path has a resistance which is altered by the sensed strain, stress or force. Combining a plurality of sensing elements coupled to a common substrate forms a sensing system.