Image of the Day: Micro Cleaners

Microrobots kill bacteria and clean surfaces covered in biofilm.

Chia-Yi Hou
May 8, 2019
Catalytic antimicrobial robots are removing biofilm from a petri dish.

Biofilms are layers of microbes that can attach stubbornly to the surface of objects, including human teeth. For laboratory and medical settings, biofilms pose a problem for keeping clean conditions. To help out, researchers have developed magnetic microrobots that can remove Streptococcus mutans from surfaces by generating free radicals that kill the bacteria and scrubbing away the biofilm using iron oxide particles controlled by the microrobot’s magnetic field.

G. Hwang et al., “Catalytic antimicrobial robots for biofilm eradication,” Science Robotics, doi:10.1126/scirobotics.aaw2388, 2019.

Researchers prepared petri dishes containing biofilms and either left them untreated as a control, embedded them with nanoparticles (NPs) of iron oxide, or treated them with the antimicrobial microrobots (CARs) that kill bacteria and use the nanoparticles to scrub away the biofilm using a magnetic field. The control and NP treatment (left and middle panel) show the growth of bacteria in green and the biofilm matrix in red. The CAR treatment shows no growth of bacteria or biofilm (right panel).