Propelling micrometre-sized drones using light only and exerting precise control: Physicists at the University of Würzburg have succeeded at this for the first time. Their microdrones are significantly smaller than red blood cells.

A hand-held laser pointer produces no noticeable recoil forces when it is "fired" -- even though it emits a directed stream of light particles. The reason for this is its very large mass compared to the very small recoil impulses that the light particles cause when leaving the laser pointer. [1]

Figure 1. Microdrones with light-driven nanomotors

Figure 1 shows in doing so, they were inspired by ordinary quadcopter drones, where four independent rotors allow complete control of the movements. Such control possibilities offer completely new options for the usually extremely difficult handling of nano- and micro-objects, for example, for the assembly of nanostructures, for the analysis of surfaces with nanometre precision, or in the field of reproductive medicine. [2]

Ordinary Quadcopter Drones as Models

The researchers were inspired by basic quadcopter drones, where four separate rotors enable full regulation of the movements. Such control practicability provides totally new options for the generally very tough handling of nano- and micro-objects, for instance, for the examination of surfaces with nanometer accuracy, for the assembly of nanostructures or in the domain of reproductive medicine. [3]

Precise fabrication based on single-crystal gold

The extremely precise fabrication of the nanomotors is crucial for the function of the microdrones. The use of accelerated Helium ions as a means to cut nanostructures from monocrystalline gold has turned out to be a game changer. In further steps, the drone body is produced using electron beam lithography. Finally, the drones must be detached from the substrate and brought into solution.

In further experiments, a feedback loop is being implemented to automatically correct external influences on the microdrones to control them more precisely. Furthermore, the research team strives to complete the control options so that the height of the drones above the surface can also be controlled. And of course, another goal is to attach functional tools to the microdrones. [4]

References:

1. https://www.sciencedaily.com/releases/2022/04/220421130941.htm
2. https://scitechdaily.com/tiny-microdrones-propelled-by-light-driven-nanomotors/
3. https://www.azorobotics.com/News.aspx?newsID=12908
4. https://mixpoint.in/breaking-news/2022/04/microdrones-with-light-driven-nanomotors/

Cite this article:

Thanusri swetha J (2022), Microdrones with light-driven nanomotors, Anatechmaz, pp.158