When designing a new legged robot it is important to think about what the robothas to do. It is not the same a non-stop walking robot than a legged robot whichhas to be at the same position much longer than moving.For the second kind of robot, it could be a great improvement to add a breakin each actuated joint, so it is not necesary to wasted energy during the stopedtime. And not only that, thanks to the brake, it is possible to achive heavier loadsusing a speci c walking pattern in which you always place the center of mass onthe three legs that are not moving in that moment (with the brake activated),while make the next step with the fourth leg.The most common braking systems are mechanic, whether using an electro-magnetic brake or some other kind of friction-based brake in addition to anysort of actuator, e.g., hidraulic, electric, . . . Even though they have been deeplystudied, there are some disadvantage by using mechanic braking systems, i.e., thehigh prices and the bad holding torque/weight relation, important aspect for alegged robot.This thesis presents a conceptual idea for a braking system based on thethermodinamic control of Hot Melt Adhesive (HMA), as well as the basic char-acteristics of this material and a long leg prototype which shows the feasibilityof this concept.