An active-passive variable stiffness elastic actuator for safety robot systems. - Ren-Jeng Wang; Han-Pang Huang (IROS, 2010)

Active Variable Stiffness Elastic Actuator: design and application for safe physical human-robot interaction. - Ren-Jeng Wang; Han-Pang Huang (ROBIO, 2010)

ADEA - Active Variable Stiffness Differential Elastic Actuator : Design and application for safe robotics. - Ren-Jeng Wang; Han-Pang Huang (ROBIO, 2011)