Recent Research In Nanometric Interfaces Center

[paulevans]

(NC & T) The recent investment made by the University of Leicester in the Center for Virtual Microscopy and the Nanometric Interfaces Center, has placed the university in a key position to take the lead in the measurement of Casimir force in novel geometries.

The strength of Casimir is a mysterious interaction between the objects that comes directly from the quantum properties of the so-called "vacuum". Within classical physics, emptiness is the simple absence of all matter and energy, whereas quantum theory tells us that it is in fact a boiling mass of quantum particles that constantly appear and disappear from our observable universe. This gives the vacuum an unimaginably large energy density.

The research will help to overcome a fundamental problem of all nanomachines (that is, machines whose individual components are the size of molecules), because in these tiny dimensions everything is "sticky", and when one component comes in contact with another, Adhere to each other. If a method can be found to transmit forces through small spaces, without the problems described, then it may be possible to build nanomachines that work freely, without sticking together.

According to the theory of the quantum field, each particle is a wave of an underlying field in the vacuum, and it is only the energy of the wave itself that we can detect.

A useful analogy is to consider our observable universe as a mass of waves on an ocean whose depth is immaterial. From that sea, our senses and all our instruments can only detect waves directly, so it seems that trying to detect anything below them, the "vacuum" in itself, is impossible to achieve. But it is not exactly like that. There are subtle effects of zero-point energy that lead to perceptible phenomena in the "normal" universe, which we can observe.

An example is a force, predicted in 1948 by the Dutch physicist Hendrik Casimir, who comes from the energy from the zero point. If two opposing mirrors are placed in the empty space, they produce a disturbance in the quantum fluctuations, with the result that a pressure is exerted that tends to join the mirrors.

However, detecting Casimir's strength is not easy, since it only becomes significant if the mirrors approach less than one micrometer. Producing sufficiently parallel surfaces, with the required precision, has had to wait until the appearance of the tools of nanotechnology, with which it is feasible to make the exact measurements of that force.

The new instrumentation from the University of Leicester will allow researchers to extend their measurements to even more complex forms, and, for the first time, to look for a way to reverse Casimir's strength.

This would be a discovery that would open a new field of research, since the Casimir force is a fundamental property of the void, and inverting it is similar to reversing gravity. Technologically, this would only have relevance at very small distances, but it would revolutionize the design of micro and nanomachines.