电-力耦合场下导电弹性介质的表面失稳

Surface instability of a conductive elastic medium subjected to electro-mechanical coupling field

文章利用线性摄动理论,对扩散调控的弹性固体表面在受到单向均匀远场应力和电场的作用下进行了研究;采用线性稳定性分析得到了临界失稳波长,得出了摄动增长率随扰动波数的变化曲线;在分析过程中,考虑了弹性应变能、表面能和静电能的共同作用。分析结果表明,表面能总是抑制表面失稳,弹性应变能促进表面失稳,而静电能有利于表面失稳。表面形态的演化是由于几种能量相互竞争导致的结果,最终趋于总自由能最小。通过机械应力和电应力调控的表面自组装可以生成周期性纳米结构,从而为纳电设备的制造提供模板。

By means of the linear perturbation theory, the diffusion-mediated surface instability of the elastic solid subjected to a uniaxial uniform far-field stress in an electric field is studied. The critical instability wavelength is obtained by using linear stability analysis. The curve of the perburbation growth rate versus the disturbance wavenumber is plotted. The elastic strain energy, the surface ener- gy and the electrostatic energy are taken into consideration. The results indicate that the surface ener- gy always stabilizes the solid surface, the elastic strain energy always promotes the instability and the electrostatic energy destabilizes the surface. The surface morphological evolution arises from the ener- gy competition which attempts to minimize the total free energy. The periodic nanostructures can be formed by the mechanical stress and the electric stress controlled surface self-assembly which is desira- ble for making the template for nanoelectronic devices.