Electrokinetic microfluidic devices for rapid, low power drug delivery in autonomous microsystems

In this work, a low power and robust electroactive microwell-based implantable drug delivery system, intended for use with autonomous microsystems, is presented. The device comprises of an upper silicon based structure in which the drug storage sites are defined and a lower electrically functionalized PDMS (polydimethylsiloxane) backing. The drug ejection mechanism developed here exploits localized electrokinetic effects to control both the release time and release rate of chemicals stored in independent well sites. It is shown how this can reduce the dosage time from hours to seconds over previous diffusion based approaches, using as little as 20 mJ of energy per dose. This paper focuses on presenting the design and characterizing the electrokinetic transport mechanics which govern the release time and dispersal pattern of the well contents using a series of experimental and numerical techniques.