Maxwell deamon, nano-machines and "tractor beams"

Imagine:
you connect a small laser-pen on the side of a heavy box, and the pen makes the box move (slowly) in the opoposite direction.

Impossible? Perhaps not for long.
Read this article (from Science Daily), where they discuss of how to implement a Maxwell deamon and how to turn it into a "pushy beam":
"
Applications of the nanotechnology machine could include trapping molecules to generate a force in front of a solid object using a laser pen. By shining the pen in the direction you want the object to move, the force of the molecules could be harnessed to push the object along.
"