Euler Arches and Duffing Springs of a Few Nanometers in Size

The molecular dynamics of a rod-like oligomer of N -isopropylmethacrylamide and helical oligomers of pyridine-furan several nanometers in size are studied by full-atomic computer simulation. It is shown that, under compression and tension, the dynamics of the oligomers are similar to the dynamics of classical bistable constructions such as Euler arches and Duffing oscillators. The critical values of power loads at which the dynamic states of oligomers bifurcate and the dynamics of oligomers become bistable are determined. It is shown that in the region of bistability oligomers can switch to the regime of spontaneous vibrations activated by thermal fluctuations of the environment at room temperature. For the regime of spontaneous vibrations, the effect of stochastic resonance is demonstrated. The possibility of using bistable oligomers for the detection of single organic molecules in solutions is discussed.