Electric Current with square wave

First of all, thank you for taking your time to read this post. Hopefully, you guys can give me some pointer. I have been using the classkit COMSOL 5.5 while following closely with the example (www.comsol.com/model/dielectrophoretic-separation-of-platelets-from-red-blood-cells-17013) and trying to replicate the result using a different kind of wave. Essentially, I would like to apply a square wave instead of the typical sine AC current in the example. I see the example uses the electro current physics module and was wondering if I can achieve my desired result using the electro current module.