The electric field is created by the laser beam:
"A deviation from the second law of thermodynamics has been demonstrated experimentally for the first time. [...] To test the idea, the researchers put about 100 latex beads - each 6.3 µm across - into a water-filled cell, which was placed on the stage of a microscope. The researchers focused a laser onto one of the beads, which induced a dipole moment in the bead and drew it towards the most intense region of the electric field in the laser beam." http://physicsworld.com/cws/article/news/2002/jul/16/small-systems-defy-second-law
"Optical tweezers are capable of manipulating nanometer and micron-sized dielectric particles by exerting extremely small forces via a highly focused laser beam. The beam is typically focused by sending it through a microscope objective. The narrowest point of the focused beam, known as the beam waist, contains a very strong electric field gradient. Dielectric particles are attracted along the gradient to the region of strongest electric field, which is the center of the beam." https://en.wikipedia.org/wiki/Optical_tweezers
In an electric field, water develops a specific pressure that pushes in all directions and can result in an eternal (limited only by the deterioration of the system) motion, on condition that the system provides suitable channels for water to move through. The pressure is NON-CONSERVATIVE. This means that, if suitably harnessed, the pressure will do work AT THE EXPENSE OF AMBIENT HEAT (in violation of the second law of thermodynamics). Here is a simple example:
"A plane capacitor with rectangular plates is fixed in a vertical position. [...] The capacitor is charged and disconnected from the battery. [...] The lower part of the capacitor is now brought into contact with a dielectric liquid:
When the plates contact the liquid's surface, a force in the upward direction is exerted on the dielectric liquid. The total charge on each plate remains constant and there is no energy transferred to the system from outside." [END OF QUOTATION]
There IS energy transferred to the system from outside. The rising water can do work, e.g. by lifting a floating weight, and this work can only be done at the expense of AMBIENT HEAT.
What is the molecular mechanism behind the effect? Here is a schematic presentation of water dipoles in the electrical field:
If it were not for the indicated (with an arrow) dipole, other dipoles in the picture are perfectly polarized as if there were no thermal motion. Of course, this is an oversimplification – thermal motion is a factor which constantly disturbs the polarization order. The crucial point is that, as can be inferred from the picture, any thermal disturbance contributes to the creation of a pressure between the plates. Consider the indicated dipole. It has just received a strong thermal stroke and undergone rotation. As a result, it pushes adjacent dipoles electrostatically, towards the plates. Macroscopically, the sum of all such disturbances is expressed as a pressure exerted on the plates. One can also say, somewhat figuratively, that the indicated dipole has absorbed heat and now, by pushing adjacent dipoles, is trying to convert it into work.