Inspired by http://www.thingiverse.com/thing:503457
The OpenSCAD file is provided so feel free to adept to your own microphone, the default has been made for a Zoom H1 recorder. Print this piece twice, snap it together, put some rubber bands on it, tighten it to the IKEA arm with the screws that came with it and your good to go (created by removing the lamp part from a TERTIAL lamp, you can buy it for only € 8,99 at IKEA).
Printed using a CEL Robox printer and Colorfabb _XT filament but I guess any type of filament should do, this is a easy part to print and you don't need to use a very high resolution (I used 300 micron for this one).
Just print it twice, snap it together, add some rubber bands, attach it to a TERTIAL arm and you're good to go.