The paper reviews the forces acting on particles in microelectrode structures under alternating current (AC) electrokinetic conditions. It discusses the manipulation and separation of bioparticles using dielectrophoresis (DEP), where the dielectrophoretic force is influenced by the frequency and magnitude of the applied electrical field. The study highlights the impact of high electrical fields on heat dissipation and the resulting thermal gradients, which can induce fluid motion through buoyancy and electrothermal forces. The paper identifies a new type of fluid flow at low frequencies (up to 500 kHz) caused by the tangential electrical field on the diffuse double layer of microfabricated electrodes. It also examines the effects of Brownian motion, diffusion, and buoyancy force on the controlled manipulation of sub-micrometre particles. The authors calculate the orders of magnitude of various forces acting on a 282 nm latex particle in a model electrode structure and compare these with experimental results. The results show that electrothermal forces can dominate over DEP forces under certain conditions, and the influence of each force on particle behavior is described. The paper provides a comprehensive analysis of the forces involved in AC electrokinetics, offering insights into the behavior of particles in microelectrode structures.The paper reviews the forces acting on particles in microelectrode structures under alternating current (AC) electrokinetic conditions. It discusses the manipulation and separation of bioparticles using dielectrophoresis (DEP), where the dielectrophoretic force is influenced by the frequency and magnitude of the applied electrical field. The study highlights the impact of high electrical fields on heat dissipation and the resulting thermal gradients, which can induce fluid motion through buoyancy and electrothermal forces. The paper identifies a new type of fluid flow at low frequencies (up to 500 kHz) caused by the tangential electrical field on the diffuse double layer of microfabricated electrodes. It also examines the effects of Brownian motion, diffusion, and buoyancy force on the controlled manipulation of sub-micrometre particles. The authors calculate the orders of magnitude of various forces acting on a 282 nm latex particle in a model electrode structure and compare these with experimental results. The results show that electrothermal forces can dominate over DEP forces under certain conditions, and the influence of each force on particle behavior is described. The paper provides a comprehensive analysis of the forces involved in AC electrokinetics, offering insights into the behavior of particles in microelectrode structures.