To create an autonomous TETRIX^® robot, you can use the LEGO^® NXT Intelligent Brick. The Hard Point Connectors to enable this are available at LEGO Education. You will also need the HiTechnic Servo Controller, HiTechnic DC Motor Controller, 10-cell battery pack, and enough Studless Technic Beams, Angle Beams, and Long Connector Pegs to attach the NXT elements to a TETRIX robot design.