非饱和介电凝胶的力学性能及力电失稳行为研究

Study of the Mechanical Property and Electromechanical Instability of Unsaturated Dielectric Gel

力-电耦合场作用下,介电凝胶的体积、形状会发生相应的变化,在智能传感器与促动器等领域具有广阔的应用前景.浸入溶液中,介电凝胶将吸收溶液而溶胀.当外界溶液的量足够多时,介电凝胶将吸收足量的溶液而达到饱和状态;但如果外界溶液的量较小,没有足够的溶液可被吸收时,介电凝胶将处于非饱和状态.基于介电凝胶大变形与极化理论,对非饱和介电凝胶在等双轴应力与电场耦合作用下的力学行为及力电失稳现象进行研究.结果表明,饱和度越低介电凝胶的刚性越大,材料越硬;预应力技术可以提高介电凝胶的力电稳定性,预应力越大,力电失稳出现时的临界电压值越高.

Under the action of the electro-elastic fields, the volume and morphology of the dielectric gels may change remarkably, which make them widely used in smart sensors and actuators. When immersed in water, the network of the dielectric gel can imbibe large amounts of water and swell. If there is adequate external solvent, the dielectric gel may imbibe enough solvent and be in a saturated state. Conversely, it may be in an unsaturated state. The mechanical behavior and electromechanical instability of unsaturated dielectric gel had been analyzed by means of the theory of dielectric polarization. The results show that the lower the saturation of dielectric gel, the stronger of the rigidity; the prestressed technology can improve the stability of the dielectric gel, the larger of the prestress the higher the critical voltage.