Researchers from China have developed a laser-based tractor beam that can be used to move larger objects in the macroscopic range. In the future, technology could move vehicles on Mars.
Qingdao (China). Physics has been working on moving small objects with light for a long time. In 2010, for example, scientists at the Australian National University in Canberra manipulated a laser beam in such a way that it looked like a tractor beam. At that time, however, Andrei Rode’s team only succeeded in transporting the smallest particles in the microscopic range.
According to a publication in the specialist journal Optics Express , researchers at Qingdao University of Science and Technology (QUST) in China have now developed a laser -based tractor beam that can also be used to move larger objects in the macroscopic range. As Lei Wang explains, this is possible because the attraction of light has a much larger amplitude.
“In earlier studies, the light pulling force was too low to pull a macroscopic object. In our new approach, the light attraction has a much larger amplitude. In fact, it is more than three orders of magnitude greater than the light pressure used to propel a solar sail that uses the momentum of photons to exert a small amount of thrust.”
Pendulum moved with laser light
In the laboratory, the researchers have succeeded in using the tractor beam of laser light to attract a pendulum that is about five centimeters long. To do this, they aimed the laser at the pendulum, which then visibly moved in the direction of the light.
“We found that the pulling force was more than three orders of magnitude larger than the light pressure. In addition, the laser draw is repeatable and the power can be adjusted by changing the laser power. Our work shows that flexible light manipulation of a macroscopic object is possible if the interactions between the light, the object, and the medium are carefully controlled. It also shows how complex the interactions between lasers and matter are and that many phenomena are still far from being understood at both the macro and micro levels.”
Mit dem aktuellen Traktorstrahl können noch keine größeren Objekte bewegt werden. Zudem funktioniert die Technik nur unter eingeschränkten Bedingungen im Labor.
Pendel aus Graphen-Siliciumoxid-Verbundstruktur
Das verwendete Pendel besteht aus einer Graphen-Siliciumoxid-Verbundstruktur. Wenn diese mit dem Laser angestrahlt wird, entsteht ein umgekehrter Temperaturunterschied. Die Rückseite wird dadurch heißer als die Seite, die vom Laser getroffen wird. Auf der Rückseite des Pendels erhalten die dortigen Gasmoleküle dadurch mehr Energie und drehen sich zum Laser. Dieser Effekt tritt aber nur in einer Edelgasatmosphäre auf, deren Druck deutlich niedriger ist als der Druck der Erdatmosphäre.
However, according to Earth’s atmosphere, the atmospheric conditions on Mars are similar to the conditions of the experiment. According to him, it is therefore conceivable that a tractor beam could move vehicles on the red planet in the future.
“Our technique enables long-distance non-contact dragging, which can be useful for various scientific experiments. The rarefied gas environment we used to demonstrate the technique is similar to conditions on Mars. Therefore, one day it may have the potential to manipulate vehicles or aircraft on Mars.”
