The tractor beam: how many times have you seen it at work in science fiction films, novels and TV series? Yet it is no longer the stuff of fantasy: thanks to advances in physics and technology, through the use of laser or acoustic waves, it is becoming reality
It is still an immature technology, but it is worth investing time in research: the potential applications are many (above all, pharmaceutical research and high-precision production). Either way, the development of tractor beams could have a significant impact on the future of physics, technology, and how we tackle complex problems.
What is a tractor beam?
As mentioned, these are beams of laser or acoustic waves to be used to remotely control particles, molecules or larger objects. The concept of “tractor beam” is almost a century old: it was introduced for the first time by the writer science fiction Edward Elmer “Doc” Smith in 1931.
Over time, it has become a recurring element in science fiction works. The Star Trek series is famous, where the tractor beams are represented as a beam of energy used by spaceships and capable of grasping and moving objects from a distance.
And today? From the realm of science fiction we have already entered the field of research. The tractor beam is no longer theory: recent scientific and technological advances have made it real.
In 2013, the scientists they managed to develop a tractor beam capable of manipulating objects on a microscopic level. Since then, several studies have achieved similar results, creating tractor beams on a small scale.
In 2014 a team of researchers produced a reversible tractor beam capable of moving hollow gold-coated glass spheres several centimeters against the flow of a laser.
2016, another search employed tractor beams to move bacterial cells.
In 2019, a study used tractor beams to assemble nanoscale materials through a process known as “photonic nanowelding.”
They may seem trivial developments, but in reality they offer great potential to revolutionize many sectors. In the medical field, for example, tractor beams could give us highly accurate and minimally invasive surgeries.
The science behind tractor beams
Tractor beams basically work through sound, or light.
A number of relatively recent studies have already shown that there is a force capable of pulling objects towards a beam of photons.
Fundamental research was conducted in 2010, Followed by experimental confirmations in 2011. Just a few months ago, in the January 2023, a research team has definitely proved the optical attraction on macroscopic objects, thanks to the phenomenon of the so-calledKnudsen diffusion".
In terms of sound, however, study of acoustic waves to manipulate small particles goes back even to 1982. In 2015, research has demonstrated the use of ultrasound-based tractor beams to lift and manipulate particles. The phenomenon, we talked about it here, is known as “acoustic levitation".
Possible uses of tractor beams
Currently, tractor beams are under research and have no concrete applications. However, understanding the science behind this technology suggests several potential future applications.
- Precision manufacturing: with the tractor beam it could help us assemble and manage minute components, improving efficiency and precision in the production of complex products.
- Biomedical uses: Tractor beams could allow small materials to be moved non-invasively, facilitating the targeted delivery of drugs and therapies.
- Material Science: The tractor beam could be used to examine and manipulate materials at the nano and microscopic levels, leading to the development of new materials and applications.
- Space Exploration: With more powerful tractor beams, asteroids or space debris could be captured and manipulated to prevent accidents, collect useful materials, and facilitate safe space exploration.
- Robotics: Robots could use tractor beams to control and manipulate very small objects, increasing the precision and efficiency of their actions.
- Environmental protection: A tractor beam could help remove particles or contaminants from the environment, such as microplastics in the oceans or pollutants in the air.
- Security and Defense: One day, tractor beams could be used to handle and control small objects in security and defense settings, such as defusing explosives or neutralizing drones.
Tractor beam challenges and limitations
Despite the great potential of tractor beams, there is no doubt that there are still several challenges to face (especially in the field of laser-based “optical” tractor beams) before they can be transformed into a “mass” technology.
First of all, the dispersion of light poses problems of no small importance. The directionality of the laser beam must be high to apply a targeted force to the object, as the light scatters in all directions. Depending on the characteristics of the object, such as mass and size, a different laser may be needed.
For macroscopic objects, then, the optical traction force must increase significantly, which implies an increase in size, complexity and cost of devices. The choice of parameters therefore becomes very delicate for both the equipment and the object being manipulated.
Another problem with the "laser" tractor beam is the overheating. At the moment, the high light intensity of any "optical tweezers" to be used in the medical field could damage biological samples.
Despite these challenges, tractor beams offer numerous application opportunities. With constant research and development, we could overcome these limitations and pave the way for new and exciting applications.
Imagine a future where we can handle objects without physical contact, allowing us to work with hazardous or sensitive materials without the risk of harm. A future in which (as happened with other technologies) we will watch an old episode of the Roddenberry saga and it will seem only a prediction. And what about teleportation with that?
