Liquid-bodied robot combats infections on medical implants

Jamie Liu

Infections on medical devices implanted in human bodies can now be tackled more easily by the world's first liquid-bodied robot developed by an international research team led by the Chinese University of Hong Kong.

The university said bacteria clusters form "biofilm barriers" when they stick to non-biological surfaces, such as immune-deficient medical implants, causing drug-resistant and chronic infections that may lead to death.

Antibiotics often fail to penetrate these barriers, and bacteria in biofilms can share resistance genes, making them harder to treat. Additionally, removing infected implants surgically risks secondary trauma.

To overcome these challenges, the new liquid-bodied robot uses a type of hydrogel that is both elastic and viscous in nature and can be magnetically controlled, enabling it to physically and chemically dismantle bacterial biofilm, CUHK said.

Lead researcher Zhang Li, a professor from the university's Department of Mechanical and Automation Engineering, explained that magnetic fields help the robot change between a stretchy state and a liquid state, adjusting to different conditions in the human body. "In elastic mode, it rotates, rolls and overcomes obstacles within the body. In liquid mode, it deforms into a fluidly robot to infiltrate crevices and eradicate any biofilm within them," he added.

The robot mechanically disrupts biofilm structures and weakens their protective effects. Then, it releases antimicrobial agents to target bacteria cells. Finally, the robot forms bonds with biofilm fragments, which prevents infections from recurring.

In animal testing, researchers were able to reduce biofilm on a 3D-structured hernia mesh by 84 percent after treatment, while 87 percent of bacteria on a metal tube installed in the bile duct were killed.

The CUHK-led study is conducted in partnership with Nanyang Technological University in Singapore and the Max Planck Institute for Intelligent Systems in Germany.

jamie.liu@singtaonewscorp.com