The function of the key element of the SMA, is based on a mutual alternating slipping of two systems of filaments. Its contraction is caused by the attractive effect of van der Waal's forces between the functional particles among the filaments. The relaxation is attained through the repulsive effect of the electrostatic repulsive forces between the functional particles. The alternating change of ionic concentration in the area of the particles results in the alternating function of van der Waal's attraction and repulsive electrostatic forces. The size and material of the particles, their configuration and working temperature must be specifically optimized. The total contraction of the key element results from the summation of its partial contractions. The total force and contraction of the SNA result from the summation of the key elements in the parallel (collateral) and/or serial (linear ranked) arrangements, respectively. Large compound actuators with high performance can be built from key elements using the modular design.