Bond breaking and formation at the point of contact can only be treated empirically. Example of a MEMS nickel gear train. Courtesy Prof. H. Guckel, University of Wisconsin. These devices are typically much smaller than the micro-gears. They are so miniscule that materials defects and surface effects 'have a large impact on the performance of the device.
Bond breaking at defects can lead to plastic deformations.
These effects vary with temperature, and in the smallest devices, the atomicity shows up through stochastic noise. Systems smaller than about 0.01 microns are too small to be in the thermodynamic limit, and anomalous statistical mechanical effects are important. These effects are beyond continuum elastic theory. Courtesy Prof. M. Roukes, CalTech. We have developed an algorithm which combines electronic, atomistic and finite element simulations into a seamless, self-consistent monolithic simulation.