title: Modeling of Drug Delivery by A Pump Driven Micro-Needle Array System.
abstract: BACKGROUND
  Micro-needles were proposed as one of the alternatives to deliver drugs painlessly passing through stratum corneum in recent years. In this work, a mathematical model is presented to characterize the in fusion flow of a hollow micro-needle array driven by a micro-pump.
  
  
  METHODS
  By assuming the injection of each micro-needle undergoes a spherical expansion and diffusion, the model is able to calculate the time-varying expansion radius, and the diffusion boundary, provided that the material properties and the micro-needle system parameters are known.
  
  
  CONCLUSIONS
  The calculation results show that the expansion caused by the infusion of micro-needles stops and the flow rate drops to zero in a short time. However, the diffusion boundary is much bigger than the expansion and the infusion continues if the surrounding material is absorptive. The experimental results of jet infusion through a single needle in silicon rubber and polyacrylamide gel agree with the calculation results qualitatively.
authors.affiliation: School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Chen
authors.affiliation: School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou, China.
authors.forename: Min
authors.initials: M
authors.lastname: Pan
authors.affiliation: Department of Mechanical Engineering, University of Texas, San Antonio, USA.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Feng
keywords: Drug delivery system; fluid infusion; infusion flow; micro-needle