First light-seeking synthetic nanorobot developed

Scientists have developed the world's first light-seeking synthetic nanorobot which may help surgeons remove tumours and enable more precise engineering of targeted medications.
It has been a dream in science fiction for decades that tiny robots can fundamentally change our daily life. The famous science fiction movie "Fantastic Voyage" is a very good example, with a group of scientists driving their miniaturised Nano-submarine inside human body to repair a damaged brain.
However, in the real world, it is quite challenging to make and design a sophisticated nanorobot with advanced functions.
Now, a team of researchers led by Dr Jinyao Tang from the University of Hong Kong, has developed the world's first light-seeking synthetic nanorobot.

With size comparable to a blood cell, those tiny robots have the potential to be injected into patients' bodies, helping surgeons to remove tumours and enabling more precise engineering of targeted medications.
Given each nanorobot is only a few micrometre in size which is 50 times smaller than the diameter of a human hair, it is very difficult to squeeze normal electronic sensors and circuits into nanorobots with reasonable price.

Currently, the only method to remotely control nanorobots is to incorporate tiny magnetic inside them and guide the motion via external magnetic field.
The nanorobot developed by Tang's team use light as the propelling force.

The team demonstrated the unprecedented ability of these light-controlled nanorobots as they are "dancing" or even spell a word under light control.
With a novel nanotree structure, the nanorobots can respond to the light shining on it like moths being drawn to flames. Tang described the motions as if "they can "see" the light and drive itself towards it".
The team gained inspiration from natural green algae for the nanorobot design. In nature, some green algae have evolved with the ability of sensing light around it.
Even just a single cell, these green algae can sense the intensity of light and swim towards the light source for photosynthesis. Tang's team spent three years to successfully develop the nanorobots.

With a novel nanotree structure, they are composed of two common and low-price semiconductor materials: silicon and titanium oxide.
During the synthesis, silicon and titanium oxide are shaped into nanowire and then further arranged into a tiny nanotree heterostructure.
The findings were published in the journal Nature Nanotechnology.