On the Use of Self-oscillations Excited by the Deformation of Polymer Films in the Actuators of Nanomechanical Devices

There are a number of tasks that require the creation of executive micro - or nanomechanical devices that allow you to convert one type of mechanical movement (for example, displacement) into another (for example, into oscillatory). Such devices that convert the energy of the input signal (electrical, optical, mechanical, etc.) into an output signal (for example, in controlled motion) are called actuators. Work on the creation of actors is underway in the UK, USA, Japan and a number of other countries. There are prototypes of actuators, but the problem of their autonomy has not yet been solved. In order for the actuator to become a real device suitable for practical use, it is necessary to solve a number of fundamental issues (to develop microminiature energy sources for their drive; to determine the methods and modes of activation of actuators that generate vibrations). Existing experimental and theoretical research in the field of self-oscillation of polymers allows us to hope for a solution to these problems in a simpler way. The studies performed below show that in accordance with the proposed rules for the selection of polymers for actuator drive polymethyl styrene and polycarbonate can be used as polymer systems in which self-oscillations will be excited in the frequency range of 200–250 Hz. The stretching rates at which the self-oscillations of the above polymers begin to be excited have been determined. The heat generated in this case can be used to maintain self-oscillations for a long time. The proposed approach can be considered as an alternative to mechanochemical actuators using methanol as a fuel. The ways of increasing their operating time and thermal effects when self-oscillations are excited in the frequency range of 200–250 Hz are considered. The glass transition temperatures T are calculated using the equation Tg=(∑iΔVi)p∑iaiΔVi+∑jbj, where (∑iΔVi)p is the van der Waals volume of the repeating unit of the polymer; a is a set of atomic constants characterizing the energy of a weak dispersive interaction as the average contribution of each atom to this interaction; b is a set of constants characterizing the energy of a strong specific intermolecular interaction, such as dipole-dipole interactions and hydrogen bonds.