1. The document discusses swelling and leaching of biomaterials, which result from diffusion processes. Fick's laws of diffusion describe how diffusion occurs due to concentration gradients at a rate proportional to the gradient. (2) Swelling occurs when fluid moves into a biomaterial, increasing its volume, while leaching occurs when material moves from the biomaterial into tissue fluid. (3) Both swelling and leaching can weaken biomaterials by reducing their elastic limit and strength and causing defects.