Micro-fluidic anti-microbial filter

A method for making an anti-microbial filter for a micro-fluidic system, the method comprising the steps of:

• providing a substrate;
• forming a filter membrane of a filter material on the substrate;
• and
• forming a plurality of holes through the filter membrane by
• providing a filter mask having a plurality of holes therein over the filter membrane by depositing a plurality of spacers on the filter material such that a part of each of the spacers contacts the filter material to define said plurality of recesses and holes in the filter mask, depositing filter mask material partially around the spacers and on the filter material such that the part of each of the spacers that contacts the surface of the filter material prevents the filter mask material from continuously coming between the spacers and the filter material and thereby defines one of the plurality of holes in the filter mask, removing the plurality of spacers to form the plurality of recesses and holes in the filter mask, and
• forming the plurality of holes in the filter membrane in registration with the plurality of recesses and holes in the filter mask respectively;
• and
• removing at least a portion of the substrate to expose at least some of the holes in the filter membrane.