Forces on magnetic-driven micro-tweezers based on micro-four-link mechanism

In this paper, a micro-magnetic-driven tweezers is proposed based on a micro-four-link mechanism in order to simplify structure and control of the micro-tweezers. For the micro-tweezers, the calculated models of molecular forces between microstructures and micro-tweezers or substrates are established. Equations for friction forces between the micro-tweezers and microstructure are given. Relationship between the force on the tweezers and the driving force on the micro-four-bar mechanism is determined. Current strength in the driving electromagnetic coil as a function of the driving force is given. Using above equations, the forces on the micro-tweezers in the process of cramping microstructure are analyzed. The basic conditions for lifting a given micro-weight are determined. The current intensity in the driving electromagnetic coil is determined for lifting a given micro-ring. Results can be used to design the micro-tweezers and determine current intensity in the electromagnetic coil for a given microstructure.