On the effect of the Casimir, van der Waals and electrostatic forces on the thermomechanical buckling of sandwich smart piezo magnetic nanosensor/switch plates

In this study, the thermomechanical buckling behaviour of nano-sized sandwich smart sensor/switch plates is modelled by considering Casimer, van der Waals, and electrostatic forces. Sandwich smart nano plate consists of magneto strictive and electro elastic materials in the surface layers, and metal and ceramic functionally graded materials in the core layer. The constitutive equation of the plate is obtained using nonlocal strain gradient elasticity and higher order sinusoidal shear theory. Thermal forces induced in a high temperature environment and the effects of Casimer, van der Waals, and electrostatic forces that occur when working depending on the gap between the nano smart plate and the fixed plate are also represented in the equations of motion. The thermomechanical buckling behaviour of the sandwich nano smart plate is analysed for many parameters such as sandwich structure properties, gap between the fixed plate and magneto strictivity, electro elasticity, temperature rise, and the results are presented. According to the analysis results, it has been observed that the Casimer force created by the gap is more effective than other van der Waals, and electrostatic forces. Analysing the minimum achievable gap is important for the design of sensor/switch plates in nano electromechanical systems, and this gap also provides information about the minimum achievable size of the designed system.