An interesting and rather advanced piece of research (PDF paper here) has just been accomplished, measuring the van der Waals force that surfaces exert on nearby atoms.
The apparatus shoots a beam of atoms through a narrow slot, 50 nanometers wide and 150 nanometers long. The quantum state of the atoms is affected in a way that can be detected by an interferometer. The resulting observed phase shift agrees with theory. The experiment is impressive and useful, and allows conclusions to be drawn with more certainty and precision, but does not change what was already known about van der Waals force.
The news writeup gives a different impression. The headline is, "Physicists Measure Tiny Force That Limits How Far Machines Can Shrink." Let me repeat -- the force is not new, and the measurement is consistent with existing theory. And the implication of the article, that this sets new limits on mechanical nanosystems, is completely groundless.
Theory and experiment agree that the atoms were accelerated at about 1 million times the force of gravity. That sounds very impressive. But a flea can jump many times its own height, and an atom is far less constrained by gravity than a flea. The weight of an atom is about 10^-25 newtons. A million times that is still only 10^-19 newtons. But the bonding force that holds atoms within molecules is more than 10^-9 newtons. In other words, this million-gravity force is less than one-ten-millionth of the force that holds atoms in ordinary molecules. It's impressive that it could be measured at all.
Twenty-five nanometers is a large distance for nanomachines, and the force increases rapidly as the distance decreases. But even for surfaces that are close together, held apart only by the natural repulsion of the atoms, the van der Waals force will be a small fraction of the bonding force. Well-constructed mechanical interfaces will be able to move and detach without damage and with predictable kinematics.
It's interesting -- sometimes there seems almost to be a party line that says "every new discovery about the nanoscale should be interpreted to show that nanomachines are difficult or impossible to build." The contrast between the press release and the actual paper is pretty striking. The actual research says basically nothing about the difficulty of building mechanical nanosystems, noting only that "the vdW interaction is one of the most important forces at the nanometer length scale" -- which we already knew.