Knowles was awarded a Fellowship of the Institute of Materials, Minerals and Mining (FIMMM) in 2004 in recognition of his contributions to the field of materials science. In 2015, he was also made Fellow of the Royal Academy of Engineering (FREng). He holds two European patents and has authored over 100 academic papers - five of which have been cited over 100 times - and he has also given a number of invited lectures and conference keynotes