Analytical model of initial fluid infusion by a microneedle drug delivery system

An analytical model is proposed to calculate the initial infusion of a microneedle array driven by a micropump. By assuming the initial infusion of each microneedle undergoes a spherical expansion, the model is able to calculate the time-varying expansion radius, as well as the flow rate and infusion pressure, provided that the material properties and the microneedle system parameters are known. For a selected piezoelectric micropump, our results show that the expansion under the skin stops and the flow rate drops to zero in a short time. We also found that the initial flow characteristics are strongly influenced by the material properties of the skin and parameters of the drug deliver system.