A silicon micro actuator model with large-displacement and low-voltage is presented based on principle of verticalhorizontal bending. Dynamic equation of micro actuator with axial and transverse loading is built based on Lagrange-Maxwell electromechanical analysis dynamics. Influence of temperature stress,axial electrostatic force and squeezing force are analyzed. Transverse distributed load and axial load are transformed equivalently into transverse centralized load with Runge-Kutta algorithm and finite difference method respectively. Relationships of deformation with driving voltage,regulation voltage,and axial compression quantity and temperature difference are simulated. It shows that displacement is as large as 10. 861 μm as driving voltage is only 16 V. Displacement is much greater than that of existing micro actuators. Simulation results are verified by experiments.

Contact between tip of atomic force microscope(AFM) and tested sample surface is simulated using molecular dynamics (MD).Relationship between contact force and gap is analyzed.Surface pressure distribution is discussed.Phenomena of "jump-to-contact" and "neck-separation" are observed.Hysteresis between contact process and separate process is obtained.Relationship of surface distortion radius with contact force and gap is also discussed.Only atomic layer close to contact area affects the contact force.Surface atoms close to the contact are pressed and those far from the contact are pulled.