In fact, it is more than three orders of magnitudes larger than the light pressure used to drive a solar sail, which uses the momentum of photons to exert a small pushing force."

( Optica)This macroscopic tractor beam only works under particular laboratory conditions, so it's a demonstration, not a practical development.

The researchers built a torsional – or turning – pendulum device made from their graphene-SiO 2 composite structure to demonstrate the laser-pulling phenomenon.

NASA was interested in pursuing the idea of using tractor beams to gather samples with the MSL Curiosity surface rover.

But NASA wondered if a tractor beam could draw tiny particles from the vaporized sample into the rover for a more complete study.

For one thing, there needs to be a well-understood theoretical underpinning that describes how the effect works on objects with different sizes and shapes and with lasers of different powers in different atmospheres.