Force of Microscopy: the Casimir Force

Franklin Lee

Mr. Darren Lee

Science & Technology

11 September 2024

Force of Microscopy: the Casimir Force

The Casimir Force could play an important role in designing a device that manages microscopic actions. In the world of nano, the Casimir Force is a strong factor that can disrupt specific behavior the device wants to complete. Therefore, the research of handling Casimir Force has been hot on the news—for one, on Nature Science in recent months.

What is the Casimir Force? It is, indeed, a minor topic. The Casimir Force describes the force between two parallel steel plates that forms through Quantum Fluctuation. Quantum Fluctuation is a process whereby pair-particles are created and destroyed, obeying zero-point energy. Zero-point energy can briefly be described as the energy that space must have in order to follow the Time-energy Uncertainty Principle. Zero-point energy can be derived from Heisenberg’s energy-time uncertainty principle, ∆E*∆T ≥ ħ/2. Since the product of uncertainty of energy(∆E) and time(∆T) has to be greater or equal to the set number(ħ/2), neither ∆E or ∆T can be 0. So there always is a set energy level of space that must be kept and a probability density of 100% distributed from the least energy level of space to the higher energy level of space. What it means by having probability density distributed is that the energy could exist in any energy level of space greater or equal to zero-point energy simultaneously, according to the probability density. As the observation time increases, the uncertainty of energy decreases (obeying ∆E∆T≥ħ/2 and ∆E∆T = Etotal, as ∆T increases, ∆E must decrease), resulting in less range between which energy can fluctuate. Coming back to the Casimir Force, the vacuum space in between the two parallel steel plates tends to attract each plate together because of the zero-point energy difference between them. The plate with the higher zero-point energy will attract the other plate containing less energy level of space compared to the other plate’s zero-point energy.

The researchers found that the Casimir Force can be magnified by the magnetic field and can limit the fluctuation of the energy, leading to a reduction in the formation of the Casimir force. And—working on the revelation of its mechanism—how the Casimir Force acts according to the magnetic field. They experimented by regulating the magnetic field, sophisticatedly controlling the distance between the two steel plates.

Why is this important? The handling of Casimir Force is important because we can utilize it in making microscopic machines such as sensors, robots, research, etc. This kind of nano-scale engineering is called the Nanoelectromechanical System (NEMS). It allows us to develop intricate electronic devices such as semiconductors and researching devices used for experiments.