Fringe effect problem of lateral electrostatic force in electrostatic drive comb structure is proposed.The electrostatic force of traditional parallel plate capacitor is analyzed.The effects of lateral comb gap and driven voltage on electrostatic force and fringe effect are discussed primarily.The results are compared with finite element simulation.It shows that the fringe effect is not obvious when gap is large

but nonlinear of eletrostatic force and voltage squared will appear if the voltage is too high when the gap is narrow

coupling phenomena is significant

narrower gap and higher voltage will induce stronger fringe effect and larger lateral electrostatic force

lateral electrostatic force is not a constant value and parallel plate capacitor theory is not suitable already.