FIGURE 9: Applications derived from research into bacterial motility. (A) Microfluidic mixing. (i) Free-swimming bacteria enhance mixing across the laminar flow in the Y-shaped microfluidic device, as indicated in the boxes numbered from 1 to 7. Reproduced from [67]. (ii) A monolayer of bacteria (aka ‘bacterial carpet') with a freely rotating flagellar bundle is attached to the channel wall which enhances mixing. Reproduced from [70]. (iii) A nanoengineered bacterial strain which expresses biotin at the tip of the flagella binds to the streptavidin-coated glass surface. It results in the situation where bacteria are tethered via the flagella, and the whole-cell body rotates to induce mixing in microfluidic channels. Reproduced from [71]. (B) Bio-hybrid and bio-inspired microrobots. Drug-loaded cargoes are attached to the motile bacteria containing magnetic nanoparticles or to artificial magnetic microrobots. These microrobots are then guided to the tumour target applying a magnetic field. Reproduced from [72].

67. Kim MJ, and Breuer KS (2004). Enhanced diffusion due to motile bacteria. Phys Fluids 16(9): L78–L81. doi: 10.1063/1.1787527

70. Kim MJ, and Breuer KS (2006). Use of Bacterial Carpets to Enhance Mixing in Microfluidic Systems. J Fluids Eng 129(3): 319–324. doi: 10.1115/1.2427083

71. Al-Fandi M, Jaradat MAK, Fandi K, Beech JP, Tegenfeldt JO, and Yih TC (2010). Nano-engineered living bacterial motors for active microfluidic mixing. IET Nanobiotechnol 4(3): 61. doi: 10.1049/iet-nbt.2010.0003

72. Bente K, Codutti A, Bachmann F, and Faivre D (2018). Biohybrid and Bioinspired Magnetic Microswimmers. Small 14(29): 1704374. doi: 10.1002/smll.201704374