It depends on what you want to achieve. A starting point could be to read the current angle once the gripper is closed. Anything between 0 and 90 should mean an object has been gripped. Otherwise, you missed it.
Another idea: a load sensor (same as the one in kitchen scale)
If the intent is to avoid to apply too much pressure, I saw a gripper based on inflatable fingers. This is not a servo, it is more pneumatic style.
It depends on what you want to achieve. A starting point could be to read the current angle once the gripper is closed. Anything between 0 and 90 should mean an object has been gripped. Otherwise, you missed it.
Another idea: a load sensor (same as the one in kitchen scale)
If the intent is to avoid to apply too much pressure, I saw a gripper based on inflatable fingers. This is not a servo, it is more pneumatic style.