Characterization and development of a non-electronic open-loop drug infusion system: A first step towards closed -loop control

This dissertation reports on the characterization and development of a non-electronic open-loop infusion system. The expansion of a pH responsive hydrogel provides the pressure for infusion. The hydroxyethylmethacrylate-co-acrylic acid hydrogel used in this thesis has a transition point at 5.3 and expands at pH above this value and contracts at pH below this value. The volume expansion is coupled to deform a flexible membrane and reduce the volume of a drug reservoir. Since fluid is incompressible, this change in volume translates into a net flow of drug out of the device. The device demonstrated a constant infusion of 2 muL/hr for 12 hours.;The properties of the flexible membrane are investigated through tensile testing to determine the stiffness of the membrane as a function of accelerated aging. The hydrophobic recovery of the polydimethylsiloxane following oxygen plasma activation is investigated through contact angle measurements.