Journal Article flexible electronics strain engineering stretchable strain sensors Bravais lattices MXene Review Young's modulus aerogels all-stretchable platforms ambient-pressure-dried processes assistive technology bacterial cellulose conductive polymers conformability discrete structure flexible sensors and switches graphdiyne haptics healthcare electronics heterogeneous substrates human–machine interface identification of body features interlocking structures mechanical damage endurance mechanics of materials mechanochemistry mechanocombinatorics memristors metamaterials