Professor Mingming Wu and her lab have, for more than a decade, investigated how microorganisms – from bacteria to cancer cells – migrate and communicate with their environment. The researchers aim to create a remotely controlled microrobot that can navigate in the human body. Initially, they tried designing a 3D-printed microrobot that mimicked how bacteria use their hair-like flagellum to propel themselves; these early robots were cumbersome and the effort collapsed.
Wu and her colleagues took an alternative, less literal approach to microrobot design. The primary hurdle was how to power the device to swim through the human body.
“Bacteria and sperm basically consume organic material in the surrounding fluid and that is sufficient to power them,” Wu explained. “But for engineered robots it’s tough because if they carry a battery, it’s too heavy for them to move.”
The researchers tried using high-frequency sound waves. Because ultrasound is beyond the...