biostudies-literatureWu CJSTPRESTOJapan Society for the Promotion of Sciencepgae463https://www.ebi.ac.uk/biostudies/studies/S-EPMC11518928biostudies-literatureUnknown3(10)Microrobots that can move through a network of blood vessels have promising medical applications. Blood contains a high volume fraction of blood cells, so in order for a microrobot to move through the blood, it must propel itself by rearranging the surrounding blood cells. However, swimming form effective for propulsion in blood is unknown. This study shows numerically that a surface-active microrobot, such as a squirmer, is more efficient in moving through blood than an inert microrobot. This is because the surface velocity of the microrobot steers the blood cells laterally, allowing them to propel themselves into the hole they are digging. When the microrobot size is comparable to a red blood cell or when the microrobot operates under a low Capillary number, the puller microrobot swims fPNAS nexusSurface-active microrobots can propel through blood faster than inert microrobots.PMC11518928JPMJPR2142Omori TIshikawa TWu CfalseSurface-active microrobots can propel through blood faster than inert microrobots.Microrobots that can move through a network of blood vessels have promising medical applications. Blood contains a high volume fraction of blood cells, so in order for a microrobot to move through the blood, it must propel itself by rearranging the surrounding blood cells. However, swimming form effective for propulsion in blood is unknown. This study shows numerically that a surface-active microrobot, such as a squirmer, is more efficient in moving through blood than an inert microrobot. This is because the surface velocity of the microrobot steers the blood cells laterally, allowing them to propel themselves into the hole they are digging. When the microrobot size is comparable to a red blood cell or when the microrobot operates under a low Capillary number, the puller microrobot swims f2024-01-01T00:00:00Z2024 Oct2025-04-04T01:59:29.847Z2025-04-04T01:59:29.847ZS-EPMC115189283947450310.1093/pnasnexus/pgae463