BIOMATERIAL

PROBLEM TO BE SOLVED: To provide a resorbable silicon including a pored silicon region so that the pored silicon may dissolve with time in a simulated body fluid.SOLUTION: A wafer 10 having a pored silicon region 20 is formed by anodizing a silicon wafer in an electrochemical cell containing 50 wt.% aqueous HF electrolyte. It is shown that certain types of porous silicon generates the deposition of apatite deposits both on the porous silicon 20 and neighbouring areas of bulk silicon 22 when immersed in a simulated body fluid solution. This deposition of apatite provides an indication that porous silicon of appropriate form is bioactive, and therefore also biocompatible. A form of porous silicon is dissolved in the simulated body fluid solution and this is an indication of a resorbable biomaterial characteristic.