Researchers at the University of Hong Kong have developed a synthetic light-seeking nanorobot. With size comparable to a blood cell, the tiny robot has the potential to be injected into patients’ bodies, helping surgeons to remove tumors and enabling more precise engineering of targeted medications.

Dr. Jinyao Tang, of the University of Hong Kong's Department of Chemistry, is developing light-seeking nanorobots that could one day be used in a range of medical applications. Image credit: University of Hong Kong.One difficulty in nanorobot design is to enable these nanostructures to sense and respond to their environment. Given that nanorobots are only a few micrometers in size, they do not easily accommodate electronic sensors and circuits. Thus, the only method currently used to remotely control nanorobots is to guide them via an external magnetic field.

For their nanorobot design, a team led by Dr. Jinyao Tang, of the Department of Chemistry, took inspiration from natural green algae, which have evolved the ability to sense light around them and swim toward the source for photosynthesis. The team's nanorobots are composed of two common and low-priced semiconductor materials: silicon and titanium oxide. During the synthesis, the two materials are shaped into nanowire and then further arranged into a tiny nanotree heterostructure.

In a paper describing their research, Tang’s team describes the ability of these light-controlled nanorobots to “dance” or even spell a word under light control.

“Light is a more effective option to communicate between the microscopic world and macroscopic world," Tang says. "We can conceive that more complicated instructions can be sent to nanorobots, which provide scientists with a new tool to further develop more functions into nanorobots and get us one step closer to daily-life applications.”

Although the current nanorobot cannot be used for disease treatment, Tang's team is already working on the next-generation nanorobotic system, which is being designed to be more biocompatible.