Abstract
The use of a 3He ion micro-beam technique to study the ingress/diffusion of water into a planar fibre optic grade glass and a cylindrical drug-release polymer is described. One-dimensional concentration profiles showing the depth of water ingress were produced. The depth of penetration of water into the glass was measured by fitting a Gaussian function to the concentration profile. The ingress of water into the drug-release polymer was found to be Fickian and a cylindrical diffusion model used to obtain a diffusion coefficient. © 2003 American Institute of Physics.