Acoustically and magnetically propelled nanomotors. (A) Schematic of the penetration of HeLa cells by AuNS-functionalized nanoswimmers. Reprinted with permission from Ref. [23]. Copyright©2019 American Chemical Society. (B) Intracellular siRNA delivery and gene-mRNA silencing using US-propelled siGFP/RCA-AuNWs. Reprinted with permission from Ref. [61]. Copyright©2016 American Chemical Society. (C) Brightfield and fluorescence images of HeLa cells before and after microdrilling. Reprinted with permission from Ref. [64]. Copyright©2015 Wiley-VCH. (D) Internalized wire subjected to a rotating field at varying frequencies. Reprinted with permission from Ref. [68]. Copyright©2016 Nature Research.