One of the standout innovations in this research was the microrobot's dual-surface property. While the exterior is hydrophilic to prevent clumping, the interior is hydrophobic to stabilize the air bubble. This dual modification ensures the microrobots function effectively in complex biofluids like blood or urine.
"This asymmetric surface modification, where the inside is hydrophobic and the outside is hydrophilic, really allows us to use many robots and still trap bubbles for a prolonged period of time in biofluids, such as urine or serum," says Wei Gao, professor of medical engineering at Caltech.