DNA-built nanorobots could revolutionise medicine
Robotic systems are essentially sensors and actuators, connected to, and coordinated by, an information-processing unit. These fabricated parts, mainly metal and plastic, are typically assembled together mechanically. Whereas, the nascent field of DNA-based robotics uses the self-assembly ability of biomolecules to build robotic systems. “DNA is ideal for robotics, as it can be programmed to self-assemble in specific and highly predictable ways,” explains Kurt Vesterager Gothelf, project coordinator of the EU-supported DNA-Robotics project. The project, which was undertaken with the support of the Marie Skłodowska-Curie Actions programme, managed to build many of the fundamental functions of a robot such as: sensing, actuation, information processing and movement. “We have significantly advanced the research closer to realising a functional DNA nanorobot,” says Gothelf from Aarhus University, the project host.
Modules assemble
DNA-Robotics first attempted to use cube-like DNA modules to build their individual robotic parts, each with different functions. A computer model developed by the project called ‘Polycubes’ was then used to rapidly evaluate how well these parts could be assembled together to create a robotic system. “This demonstrated that in theory cube modules could work, however this proved difficult in practice within the lab, so we changed to a chassis-based model to build our robotic parts,” adds Gothelf. In this alternative technique, organic structures inside membranes called vesicles were used as scaffolds around which to build the range of robotic modules constructed by the team. This included a nanoscale cable in a tube that can transfer information from one point to another, within a nanostructure. “This was an example of signal transduction which is essential for a robot to function, much like a human’s nervous system sends signals to various body parts so that these know how to react to environmental changes,” remarks Gothelf. While the chassis approach worked well for individual modules, the team could not get it to integrate them into a functional robotic system. “We were surprised how difficult it was to find a common platform for integration. Our initial inspiration was from macroscale modular robots, but more recently we have been looking at how nature achieves integration through compartmentalisation, for example within cell structures,” explains Gothelf. The team also built a linear actuator with motion confined to one axis. This is the first step in the ambition of developing a molecular printer capable of acting as a catalyst for the chemical reactions necessary to form the DNA-based robotic modules. To control this molecular printing, the printer head needs to first move along one dimension, then another.
Advanced nanoscale behaviour
The ability to create advanced robotic behaviour at nanoscales has significant implications for many sectors, particularly medicine in the design of customised smart drugs that deliver treatment in response to specific bodily signals. Indeed, the Technical University of Munich, a project partner, has developed a structure that can recognise and then encapsulate specific viruses to deactivate them. Other partners are working on DNA robots that can induce a cascade of intracellular signals that trigger the death of cancer cells. “To maintain Europe’s competitive edge, it is essential that we train future researchers in this area. We are proud to be contributing 14 early-stage researchers, highly trained and ready to advance the field,” concludes Gothelf. The project team are now working to overcome the integration challenge and ensure that their robotic structures are safe within the human body, alongside reducing production costs.
Keywords
DNA-Robotics, DNA, robot, smart drugs, biomolecule, molecular printer, nanoscale, vesicle, membrane, signals, information
