▁couple d ▁to ▁mechanical ▁forces ▁( “ c oval ent ▁polym er ▁me ch ano chem istry ” ), ▁including ▁single - m ole c ule ▁studies ▁of ▁associ ative ▁exchange ▁re actions ▁as ▁well ▁as ▁me ch ano chem ical ▁path ways ▁that ▁viol ate ▁orb ital ▁symmetry ▁principles ▁in ▁the ▁absence ▁of ▁force . ▁Chem ical ▁concepts ▁that ▁have ▁emer ged ▁from ▁these ▁studies ▁include ▁“ t ension ▁tra pping ” ▁transition ▁states ▁and ▁re active ▁inter medi ates , ▁c oval ent ▁“ str ess ▁relief ”, ▁and ▁“ back bone ▁lever ▁arm ▁effects ”. ▁Material s ▁concepts ▁demonstrated ▁by ▁his ▁group ▁include ▁stress - respons ive ▁polym ers ▁that ▁strength en ▁in ▁response ▁to ▁destruct ive ▁mechanical ▁forces ▁and ▁chem ome chan ically ▁active ▁soft ▁devices ▁like ▁soft ▁rob ots ▁and ▁electro active ▁displays . ▁Work ▁in ▁his ▁group ▁in ▁the ▁area ▁of ▁su pr am ole cular ▁polym ers ▁led ▁to ▁the ▁development ▁of ▁a ▁“ mac rom ole cular ▁analog ue ▁of ▁the ▁kin etic ▁is ot ope ▁effect ” ▁that ▁has ▁been ▁used ▁to ▁pro be ▁complex ▁non - linear ▁material ▁properties ▁and ▁material ▁t ough ening ▁through ▁otherwise ▁“ me chan ically ▁invisible ” ▁interactions . ▁ ▁Current ▁research ▁O ng o ing ▁research ▁in ▁the ▁Craig ▁lab ▁brid ges ▁physical ▁organ ic ▁and ▁materials ▁chem istry . ▁Current ▁topics ▁of ▁research ▁include ▁the ▁design ▁and ▁synth esis ▁of ▁self - he aling ▁polym ers ▁and ▁the ▁use ▁of ▁contemporary ▁me ch ano chem istry