I am a researcher incorporating UR5 robot for image guided surgery. For overall analysis of the robotic arm I am suppose to prepare a thorough documentation so need to address this question. Please help me.

Hi,
In fact, the electrical brakes are used by the robot to control his acceleration and deceleration between 2 waypoints (When the robot move). The mechanical brakes are mostly used for the safety side (ex: when the e-stop is pushed) or when the robot is not electrically powered. It's really not recommended to stop a robot using the mechanical brakes because it does a really hard stop. I suggest you to do a risk assessment before go ahead with your project. Collaborative robots are not frequently used for surgery. 

Regards

Hi Mr. Philippe,

Thanks for your answer. I want to know Is there a way to activate electrical breaks by emergency stop?

I need to validate this information with Universals robots. But for right now i don't think so because an emergency stop is use and required in safety controls. The robot need to be and stay in safe mode without any source of power.