A doctoral research student at the University of Texas has built the world's smallest medical robot that cannot be seen with the human eye.

Creation of Soutik Betal, the robot measures 120 nanometers and has entered the Guinness Book of World Records for its negligible size, Fast Company reports.

The robot is basically a series of nanocomposite particles of multifunctional oxide materials that can be remotely controlled by an electromagnetic field.

Because the tiny robot is capable of interacting with biological cells, future applications could include direct medication to cells in conditions such as cancer and Alzheimer's.