BEH. 462/3.962J Molecular Principles of Biomaterials Spring 2003 o Shows that gold membran de quickly Au(oH) 12 0.8 E/V e→2H2 -0,4 0.82H+2一H2 b)20 E/V Stirred 0.145 M NaCI solution e eshowe o H=585at25° Scan rate 0000 0.010 0015 0.020 j/A cm-2 Figure 6. a)A pourbaix diagram for the gold-chloride-water system containing 0. 145M chloride ion. b) An Evans diagram for the same gold chloride-water system obtained potentiodynamically. This diagram rep illustrating the principle of the electrochemical reservoir opening mech. resents the kinetics of the gold corrosion reaction in chloride-containint anism. The materials used in prototype microchips are described in Section 4.2 Structure of the controlled release microchip o anode is a gold membrane 0.3 um thick o current limitation in design is size of battery needed to operate the device: 1 cm microchip itself could be reduced to- 2 mmx 2mn Lecture 5- Programmed Drug Delivery 5 of 12BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 o Shows that gold membranes corrode quickly • Structure of the controlled release microchip: o anode is a gold membrane 0.3 µm thick o current limitation in design is size of battery needed to operate the device: ~ 1 cm2 ƒ microchip itself could be reduced to ~ 2 mmx 2mm Lecture 5 – Programmed Drug Delivery 5 of 12