Shape optimization of a mechanically decoupled six-axis force/torque sensor

•Mechanically decoupled six-axis F/T sensor can be effectively designed by optimization framework.•The ‘principal coupling’ is proposed to define the largest cross coupling error to be minimized.•Loading test on fabricated sensor with optimal geometry verifies the optimization framework.•Maximum coupling of 3.2% was obtained in a high moment to force ratio (0.1Nm/N) specification.