For the past 70 years, we have witnessed innovations becoming smaller and smaller - a prime example being the microchip that powers all our electronics. As innovation into the nanoworld progresses, it opens previously impossible doors in the realm of medicine and life sciences.
What is “Nano”?
Before we dive into the medical applications of nanorobotics, let’s first understand what “Nano” is. The general idea of nanotechnology seems to be the science of studying and developing extremely small things. However, this is not always the case. Nanotechnology includes anything less than a micron in size in one or more dimensions. Therefore, a 1-meter long wire with a diameter of less than one micron, would still be governed by nanotechnology.
That being said, the nanorobotics or nanobots that we see in medicine do conform to the general idea of nanotechnology, since these robots must truly be small in all dimensions to carry out their specific functions. In general, these can be divided into three categories: controlled, autonomous, and organic.
Controlled nanorobotics is the nano equivalent of a driver-controlled robotic systems. It includes a nanorobot within the body that is instructed to carry out certain tasks from the outside or sends streams of sensory data outside. Without this outside connection, the nanorobot does nothing. One can think of it as a nanoscopic remote-controlled robot.
The PillCam by Medtronic is one such example. It is a digestible pill camera loaded with sensors that can relay valuable information about the patient. The camera captures images from 2 to 6 frames per second and provides high-quality image capture for diagnosis of diseases and conditions such as Crohn’s disease, obscure bleeding, and iron deficiency anemia. Such nanoscopic robotics can also be used to collect data for research aiming to find cures for cancer and other currently incurable diseases.
Another example of such technology is currently being developed at the Molecular Systems Lab at the Max Plank Institute by its head Peer Fischer. Fischer took inspiration from the helio pylori bacteria which has a corkscrew shape that can penetrate through a dense medium such as soft tissue and mucus. Following this design, Fischer's group designed carrier nanorobots that can do the same.
This branch of nanorobotics in medicine refers to nanoparticles that do not need external control and drive themselves. They are the nano equivalent of autonomous systems on the larger robotic scale. These are generally preferable since they can operate on their own, without external control. One can think of them as nanoscopic autonomous cars.
Since this field is still emerging, there are not many companies aiming to commercialise autonomous nanorobots, however, two professors from the University of Texas at San Antonio have created a magnetically powered autonomous nanorobot for medicine. This robot has a magnetic core with a ferroelectric shell. The ferroelectric shell is a permanently polarised substance that creates a changing electric field based on pressure. This changing electric field then creates a magnetic field which, when combined with the core’s magnetic field, creates motion.
This little device has a multitude of applications in the medical realm. It can be used to transport drugs to a particular cell, it can also be used to transport cells themselves, and even penetrate through a cell's membrane. This can prove to be game-changing for cancer research as it allows us to directly destroy cancerous cells.
This side of medicinal nanorobotics aims to use organic life and other stem cells that are chemically "programmed" to carry out certain functions. This form of nanorobotics is by far the least developed but most useful since it does not involve non-biological material to be inserted into the body.
Most of the current research in organic nanorobotics takes inspiration from nature itself. For example, Yang(Claire) Zeng, a Ph.D. research fellow at Harward Medical School is currently combining biology and engineering practices to make nanoscopic DNA packages that can carry drugs to different parts of the body. These DNA packages are created using origami technology, invented by Paul Rothemund, in which scaffolds of DNA are folded like paper and then smaller strands act as strings that hold everything together.
Even though this type of technology is far from complete and may even take decades to reach the market, there are many breakthroughs in this area just around the corner.
Is it really robotics?
Given all this information, a very deep-rooted question is whether nanorobotics is truly robotics or not. The answer is yes and no. No, because when we think about conventional robotics, we think of batteries, motors, electronics, and mechanical assemblies. Nanorobotics, particularly in medicine, includes none of those. Moreover, instead of using mechanical assemblies, nanorobotics uses chemical and physical assemblies to meet their ends. However, the reason why nanotechnology still classifies as robotics is that, at its very fundamental level, a robot is something that can mimic human behavior through information processing. Even though chemically accomplished, nanorobots do just that. Therefore, they are still considered robotic systems.
As innovation shifts towards the nanoworld, the conventional ideas of what defines robotics and technology must also shift to include not just engineering but much of interdisciplinary science as well. With the never-ending push toward miniaturization in every aspect, the prospect of developing a nanosized artificial machines, with all dimensions below 1,000 nm is closer to reality.
What’s next for nanorobotics in medicine?
A large part of the reason why nanorobots are facing challenges in becoming commercially available is due to a major controversial debate that is currently going on about whether nanorobotics should be allowed in medicine at all. A large majority of people believe that nanorobots manipulate the fundamental laws of nature in ways that they ought not to meddle in.
Another reason is that Nanorobotics is still a very new and upcoming field within the realms of robotics and medicine. Much of it is still in its research phases and far from being commercially available. However, we are already seeing some major breakthroughs in the field, as shown above, which are ready to be commercialized. It is only a matter of time before these nanorobots become a part of everyday medical use.