Design and first experimentation of an electromagnetically actuated ferrofluidic micropump

A volumetric micropump whose ferrofluid piston is actuated by a fixed arrangement of ferromagnetic materials and windings is presented. The main steps of the design that led to this solution are detailed. The first implements an optimization approach to determine the shape of the magnetic circuit maximizing the static backpressure withstand by the ferrofluid piston. The result is a structure consisting of ferromagnetic teeth whose width and spacing are directly related to the pipe diameter of the pump. The second step consists in analyzing and using this solution to ensure the piston actuation in a to and fro motion. The solution is formed by the repetition of three identical basic structures angularly and linearly shifted along the pipe and supplied successively, like in a stepper motor. First experimental tests performed on a prototype show the validity of the concept and the interest of fragmenting the piston into several bubbles to increase the maximal working pressure of the pump.