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by Barrett

The WAM® Arm

The WAM® Arm is a highly dexterous, naturally backdrivable manipulator. It is perhaps the only arm sold in the world with direct-drive capability supported by Transparent Dynamics™ between the motors and joints, so its control of contact forces is robust—independent of mechanical force or torque sensors. It is built to outperform conventional robots with unmatched human-like grace and dexterity.


The WAM® Arm is available in two main configurations, 4-degree-of-freedom and 7-degree-of-freedom, both with human-like kinematics. The joint ranges exceed those for conventional robotic arms.

Higher Performance Than Conventional Manipulators 

Matching advanced electronics with inherently backdrivable cable drives results in superbly graceful motions. Barrett owns the technology for the highest performance servo-electronics available in the world today. These electronics are also the smallest (43 grams) and most power-efficient servo-drive electronics available today.

Features & Benefits 

  • 270-degree average joint mobility
  • Enhances dexterity and agility even beyond human capability
  • Zero-backlash and near-zero friction
  • Extraordinarily graceful motion
  • Modular construction
  • Interchangeable components
  • Brushless rare-earth
  • High torque, low mass, lower rotor inertia, servo motors and vacuum compatibility
  • Open control architecture
  • Excellent research tool: direct access to sinusoidally commutated current amplifiers for developing advanced control algorithm
  • Lightweight design
  • Reduces moving inertia for faster cycle times
  • Compact, small footprint
  • Efficient use of space; adaptable to mobile platforms
  • Long and slender links
  • Reaches in and around obstacles with ease
  • Backdrivable
  • Extends force control along entire surfaces of joints throughout links
  • Kinematic redundancy
  • Unusually high dexterity in either 4 or 7 degree-of-freedom configurations
  • Human-like kinematics
  • Arm links form grasps around large objects (~1 m)