• Comparison between conventional gripper and HVSA-actuated gripper
• Conventional gripper equipped with tactile sensor
• Low impedance for the low-frequency range can be provided.
• Low impedance for the high-frequency range converges the structural stiffness. 
• Compliant gripper actuated by HVSA
• Impact force can be absorbed when the contact occurs.
• Contact force can be estimated by measuring passive elastic angle in the HVSA.
• Features of HVSA-actuated gripper
• 1 DOF compliant gripper actuated by hybrid type variable stiffness actuator (HVSA)
• Two fingers are operated symmetrically by using 4 bar linkage mechanism.
• Vertical motion can be achieved by using the elevation mechanism consisting of a screw-nut mechanism.

• Specifications of HVSA-actuated gripper

• Grasping fragile objects

• Comparison between conventional gripper and compliant gripper
• Grasping graphite lead
• Thin and long object: Easy to bend
• Brittle object: Easy to break
• Conventional gripper
• Low grasping speed: Success
• High grasping speed: Fail (Even though the gripper detects the contact) 
• Compliant gripper
• Low grasping speed: Success (for all stiffness)
• High grasping speed: Success (for low stiffness)

• Tofu
• Deformable object: Difficult to measure contact force
• Slippery object: difficult to grasp
• Conventional gripper
• Easily failed to detect the contact by using tactile sensor at the finger tip
• HVSA-actuated gripper
• HVSA-actuated gripper can easily detect the contact with low stiffness (or high compliance).
• A grasping force can be estimated even though a tofu is deformed by the grasping force.

               < HVSA-actuated manipulator>

• Robotic assembly using HVSA-actuated manipulator
• Square peg assembly
• Assembly tolerance: 0.1 mm
• Maximum assembly force: Less than 100 N
• 6 DOF manipualtor with force/torque sensor
• Maximum insertion speed: 30 mm/s
• HVSA-actuated manipulator
• Maximum insertion speed: 200 mm/s
• Fast assembly while maintaining low contact force can be achieved.