Illustration of optical micro-robots interacting with a biological surface.Each micro-robot is fitted with four ‘control balls’. Firing laser light into these balls makes it possible to control the micro-robots extremely accurately in three dimensions and in real time. Illustration: DTU Fotonik

New generation of laser-controlled micro-robots created at DTU

Lasers Optics Micro and nanotechnology Nanomedicine
Researchers from DTU Fotonik have become the first in the world to integrate multiple well-known technologies in a swarm of 3D-printed micro-robots. Their breakthrough opens the door to new ways for examining and manipulating stem cells and circulating cancer cells, for example.

A completely new generation of micro-robots has been produced at DTU by the Programmable Phase Optics research team at DTU Fotonik. Measuring just 40 x 40 micrometres, the micro-robots have been created using advanced 3D-laser printing technology and resemble microscopic drones. They can be fitted with a nano-size probe (as small as 25 nanometres) on one end, enabling researchers to use the robots for drug delivery, i.e. the process of conveying medication directly to sick cells. The probes can also be used for picking up individual particles and moving them.

All functions—printing, navigation and powering the probes, as well as collecting particles and delivering substances—are controlled by laser light. What is more, the nanoscopic activities can be tracked in real time using a set of simultaneous microscope cameras.

The researchers at DTU Fotonik have combined knowledge and technologies from three fields—photonics, nanotechnology and biotechnology—in developing the new 3D-printed micro-robots. The invention of the micro-robots and the presentation of their various functionalities will be published in the Nature journal Light: Science & Applications (LSA) over the coming weeks, but a provisionally approved version of the group’s scientific article is already available at 

Photo: DTU Fotonik
bservation of micro-robot. Photo: DTU Fotonik

As laser light is used to control the robots’ functions, they are currently best suited to applications outside living organisms. This means that at present, the micro-robots are not suitable for injecting into a human subject for the purpose of drug delivery. However, in the opinion of Professor Jesper Glückstad, the leader of the team of researchers, the potential for using the robots outside the human body is immense:

“Our micro-robots may well become the new tools that enable us to understand biology all the way down to nanoscale. As free-flowing drones, they can monitor processes in living cells with previously unheard-of accuracy. They can deliver targeted stimuli—chemical, mechanical and optical—to the cells, and this will help expand our understanding of how cells behave in their natural 3D environment. For example, the micro-robots may be useful tools in the context of researching stem cells or what are known as ‘circulating tumour cells’, i.e. those cells that spread a cancer via the blood vessels in a cancer patient,” he says.

The group of researchers is to continue development of the robots, equipping them with new functions, for example. The professor relates that they also hope to be able to link artificial intelligence to the robots, enabling them to work together in swarms. He explains:

“The vision for the future is to be able to use the robots inside the human body. The objective is to inject them in a small swarm, where each robot has been specialized to perform a given assignment, such as opening a cell membrane, delivering medication or closing the cell membrane again. As such, the small swarm of robots would serve as a medical team in micro-format.”

Jesper Glückstad has been invited to hold one of the six Plenary Talks at one of the most prestigious conferences in the world in the field of nanotechnology—IEEE NANO 2016—in Japan this August. Here, the professor will be presenting the entire DTU family of new, laser-controlled micro-robots.

The technology is to be commercialized by the company OptoRobotix, which is a spin-out from the Programmable Phase Optics group of researchers at DTU Fotonik.