Ground detection system for ultrasonic cutting

In one embodiment, systems and methods include using an ultrasonic cutter in a ground detection system to prevent damage to a substrate. The method of detecting a substrate comprises attaching a workpiece clamp to the substrate. The method further comprises cutting a layer of coating disposed on the substrate with an ultrasonic cutter, wherein the ultrasonic cutter operates at a frequency of about 20 kHz to about 40 kHz, wherein the layer of coating is non-conductive. The method further comprises contacting the substrate with the ultrasonic cutter.