A sample processing system includes a platform configured to hold a plurality of substrates containing biological and chemical samples to be tested. A robotic device configured to move in three dimensions relative to the substrates and to dispense reagents on the biological and chemical samples. An automated controller is coupled to operate the robotic device. A suction cup is mounted on the robotic device to access an object on a substantially horizontal plane. A gripping portion of the suction cup is further mounted at an angle relative to the substantially horizontal plane. An actuator pin is mounted to move to a first position as the suction cup deforms when the suction cup is pushed against a surface of an object to grip the object. A sensor device is configured on the robotic device to automatically detect movement of the actuator pin to the first position and provide a signal indicating the movement of the actuator pin to the automated controller.
