Hong Kong scientists develop new 'nano-swarm' robots

Using oscillating magnetic fields scientists can reconfigure the shape of the nano-swarm from overlapping ribbons (on the left) to clustered lumps (on the right).

Hong Kong (CNN)A groundbreaking new method of controlling nano-robots that emulates natural swarm behavior has been developed by scientists in Hong Kong, the first step in what is hoped could lead to a major medical advancement in the treatment of blood clots.

Nano-robots are miniscule robots or machines that are measured in nanometers, with one nanometer equivalent to one billionth of a meter. They can be used to complete nanoscale mechanical tasks, such as moving molecules, with precision and mobility.
Led by Associate Professor Li Zhang, a team of scientists from the Chinese University of Hong Kong designed and implemented a strategy of using oscillating magnetic fields to create highly reconfigurable ribbon-like swarms of nano-robots, millions of magnetic nanoparticles each less than one micron wide, or one-fifth the length of a red blood cell.
    As programmers tune the applied magnetic fields, the "micro-swarm" of nano-robots is capable of performing a wide range of structural changes, including extending, shrinking, splitting, and merging, all with a high degree of accuracy.
    "The high reconfigurability is a key discovery," Zhang told CNN whose findings were published in the science journal Nature in August. "The nanobot swarm can be operated in a controlled fashion with a high speed, which has never been reported before."
    Most significantly, the complex transformations of these nano-robots could be completed within the systems of living human and animal bodies.
    It is hoped surgeons could manipulate the nano-robots to pass through highly compact spaces within organs and blood vessels, allowing the nano-robots to resolve blood clots and assist with targeted drug delivery to cells.
    For all their potential medical applications, nano-robots are largely in the research and development stage of production, as clinical trials of nano-robots in humans have yet to be approved due to issues with strict regulations on human testing.
    Zhang's team continues to collaborate with the medical teams to explore the potential of nano-robots in clinical fields. In particular, the nano-robots could be used to address gastrointestinal diseases by maneuvering through the gastrointestinal tract.
    "My medical doctor collaborators from the Hong Kong Prince of Wales Hospitals and I expect that we could translate the nanorobotics technology to clinical applications in five years. We are doing animal studies right now," Zhang said.
    One of the objectives for Zhang's project was to emulate swarm behavior found in nature, in which groups of agents can interact and achieve what individual agents cannot. Birds, fish, insects, and even bacteria exhibit swarm behavior.
    According to Zhang, the project was also influenced by depictions of nano-robots in movies and pop culture.
    "One such movie was Big Hero Six," Zhang said. "In Big Hero Six, they show some concepts related to micro-robot swarms. Another one was Transformers, which showed how a robot dog invaded a base by deploying hundreds upon thousands of small robotic spheres."
    There are still limitations to the application of nano-robots. For instance, they cannot be used in the heart due to the high speed of blood flow, which could flush away the robots instantly.
      "It's important that we recognize the current limitations on nano-robots," Zhang said. "But I hope that more people can pay more attention to nano-robot research...it's very exciting."
      "I always tell my students, 'Let's work together and have an adventure,' because we are still learning. We'll see what lies in store."