Pros of pneumatic grippers include low cost, large grip force range, ability to operate in tight spaces and fast response times. However, pneumatic grippers are best suited to handling single part types, so they might not be a great fit if your facility produces a lot of low volume/high mix items. This gripper type also provides limited force and position control and requires compressed air to function.
Powered by hydraulic fluids, hydraulic grippers provide more gripping power than their pneumatic counterparts, making them ideal for heavy duty applications.
The main advantage of hydraulic grippers is their excellent gripping power, but with that power come several disadvantages, including the added complexity of handling oil, a pump, and a reservoir. Consequently, hydraulic grippers tend to be higher maintenance than other gripper types and they are also unsuitable for most cleanroom and many medical applications.
Electric grippers are a popular choice for many cobot applications including machine tending and pick & place. While they don't offer the same level of gripping power as hydraulic grippers, they are suitable for applications that require high speed and light/moderate gripping force. Electric grippers usually come in two-jaw and three-jaw configurations, with 3 jaw grippers often being chosen when round/cylindrical objects need to be handled.
For example, STAMIT, a machine tooling company based in the Czech Republic, used a 2-finger electric gripper from Robotiq and a UR10 cobot to take care of CNC machine tending tasks in its high mix production environment (4,000 differently tooled objects and 12 million parts total, each year).