The field of nanotechnologies, which studies phenomena at the nanometer scale, 1 to 100 nanometers, is today in full expansion and finds applications in medicine, electronics and the development of new materials. Contrary to what one might think, the power of nanotechnology objects comes less from their size, on the order of a millionth of a millimeter, than from the quantum effects associated with the nanoscale, which lead to particular properties that we can exploit for new applications. At this scale, the interweaving of scientific knowledge (nanosciences) and the engineering know-how (nanotechnologies) is artificial intelligence. In this article, we describe three recent, promising applications in nanotechnologies that will shape the future of research in nanosized robot design.
No more bad blood:
Researchers at the University of California San Diego (UCSD) have developed nanobots capable of cleaning the blood of toxins generated by bacteria. These nanorobots are about 25 times smaller than the width of a human hair and can travel 35 micrometers per second by “swimming” through blood when powered by ultrasound.
This technology, while still experimental, could open new horizons for medicine. The authors of a report on this work explain that the nanobots they developed clean our blood of bacteria and the toxins they produce. These microscopic robots are made of gold nanowires with a coating of red blood cell and platelet membranes.
During their tests, researchers report, after five minutes of treatment, blood samples already contaminated with methicillin-resistant Staphylococcus aureus (MRSA) have three times less bacteria than those untreated.
During his interview about this technology, Joseph Wang, a professor in the Department of NanoEngineering at the UCSD Jacobs School of Engineering, stated:
“By using this natural biomaterial membrane coating our microrobot, we can impart new functionality, new capabilities like the removal of pathogens and toxins from the body and from other matrices.”
Cell-sized robots:
Nanobots developed by MIT researchers in 2018 are so small and light that they could float in the air. This nanotechnology was made possible by linking 2D electronic components to tiny particles measuring between one billionth and one millionth of a meter. The final result is a robot no bigger than an ovum or a grain of sand.
The addition of photodiode semiconductors, which have the ability to detect radiation from the optical domain and transform it into an electrical signal, allows for a continuous supply of energy to the environmental sensors embedded in these robots. The small electrical charge generated is enough to allow this technology to operate without a battery.
As for the usefulness of these nanobots, the researchers plan to send them on missions in hard-to-reach places to monitor environments such as pipelines and the human digestive system. This microscopic spy can be released into the entrance, allowed to flow through the course of the pipe, and then recovered at the exit. Once harvested, the information collected by its sensors, such as the spatiotemporal concentration of certain chemical substances like enzymes and hormones, can be downloaded and then analyzed.
These nanorobots will have a wide variety of applications, particularly in the medical field. For instance, doctors can ask a patient to drink a solution and the robots can gather data about the patient’s digestive tract as they pass through it, thus allowing for better detection of health problems.
Towards controlling nanorobots:
In early June 2018, a team of Czech researchers managed to move nanoparticles 3000 times smaller than the diameter of a hair on a plate of graphene (a sheet of carbon).
The researchers published their unprecedented achievement in the field of nanosciences in the journal ACS Nano. In collaboration with Jean-Marie Lehn, winner of the Nobel Prize in Chemistry in 1987, Petr Kovaříček and fellow researchers managed to direct particles of only 30 nanometers in size for the first time.
The researchers dipped graphene, on which nanoparticles of fluorescent diamonds were placed, in a solution with a pH gradient, that is, a solution that gradually changes from an acid to a basic. Thus, the particles moved from the acid part to the basic part, and they were able to modify the pH gradient of the solution to change their direction.
In this manipulation, it was not only about moving the particles, but also about ensuring that they remained glued to the graphene plate. This form of carbon, which is a two-dimensional version of the graphite that makes up pencil leads, has the distinction of being almost transparent. This is precisely what scientists needed to observe nanoparticles with the technique of fluorescence microscopy.
Moving nanoparticles with a high degree of precision is necessary for many applications, but it is a very difficult task to achieve. However, using a graphene support simplifies the job and demonstrates opportunities for future applications. For example, we could consider moving nanoparticles on other media, allowing for human tissue modification, creation of self-cleaning surfaces, and even nanosurgery.
Challenges ahead:
The major upcoming challenges for these cutting-edge nanotechnologies is the development of life-size tests on animals and fully biodegradable versions. Nanotechnologies cause unknown and unpredictable properties to emerge, and thus researchers must carefully address the issue of risks and responsibilities in order to ensure safe use. Based on the current state-of-the-art knowledge about nanomaterial properties, it is still difficult to frame a new regulatory agenda specific to nanotechnologies, according to the recent European Union nanotechnology report.
Currently, several key regulatory instruments are being developed for the cosmetics and nanomaterials industries. The hope is that by starting to build a legal regulatory framework and by updating it as we better understand the properties of nanoparticles and how they work, we will be able to safely take advantage of new tools such as nanorobots and the exciting opportunities for high-precision work that they offer.
