The Cannae Drive is another implementation of the same idea. They say they'll launch a cubesat in a couple of years to demonstrate the drive. Their website doesn't have much information about it but here are some links:

1. http://cannae.com/cannae-is-developing-a-cubesat-thruster/

2. http://cannae.com/press-release-from-cannae/

3. http://cannae.com/cubesat/