3D printed NYLON permanent coffee filter

You can use nylon based filament to print functional permanent coffee machine filters or simple hot water filters. I'm not sure you could use PLA or ABS for it. Nylon is probably more heat stable and food safe with some water permeability properties. Here are some images of:

Instructions available at:

http://www.instructables.com/id/Make-a-Permanent-NYLON-3D-Printed-Coffee-Filter/

Here is the design of the filter:

http://www.thingiverse.com/thing:24005

Here is the different type of filter:

Source:
http://bza.tumblr.com/post/88000487342/testing-3dprinted-reuseable-coffee-filter

You can also use more complex 3d printing techniques to make your own DIY electric coffee maker:

http://diy3dprinting.blogspot.com/2014/06/diy-electric-coffee-maker-made-with.html