The University of Glasgow has created what can become the basis of a fantastic "tractor beam", although so far scientists think only about mundane, commercial things. They adapted the principles of optical traps for manipulating objects in liquid for applied purposes. Experimental optoelectronic tweezers made it possible to assemble and solder a small electronic board.
The principle of operation of the tool boils down to the fact that the laser beam forms micro-bubbles in the liquid, the pressure of which displaces the object immersed in it. If it is small enough, then, applying efforts from different sides, it can be successfully moved in three-dimensional space, without actually touching the object. The case is small - Scottish engineers have created a device that manipulates 10, 000 objects at once.
Experimental optoelectronic tweezers moved the solder particles to the desired points, where they were heated and soldered together to create simple tracks on the board. This was followed by a freeze-drying process, alternating pressure and temperature to remove excess liquid. And here it is, the finished part. It remains to decide how to assemble complex chips using this scheme, but this, as they say, is already a matter of technology.
The perspective of such a "pull beam" is that we don't need to touch the object being processed. No stands, fasteners, protective screens, etc. are required. Remember the scene from the anime "Ghost in the Shell" or the movie of the same name, in which the body of a cyborg floats through the assembly line, overgrown with components? This technology, in theory, will make it possible to translate it into reality. Although at the current stage we are talking only about optimization options for conventional robots on conveyors.