UPDATE : video uploaded . In the video the robot picks up bottle as well as avoids an object which cannot be picked.
It uses 3 sensors i.e. 1 SRF05 and 2 GP2D12 to detect objects and decide whether the object should be picked up or it should be avoided.
GP2D12 were not stable enough so i soldered 50uF capacitors between the ground and Vcc
I used a 10 RPM Dc gear motor for the arm. It gives around 8-9 Kg of torque at 9V
For using this motor i used a L293D motor driver other than the one in main board and made connections on the breadboard. Since i didn't had any of the digital outputs left i used the digital inputs and converted them to digital outputs for controlling the arm motor
The gripper is homemade
The three sensors
All the wire mess on its back
Thanks for your Support !