Design of compliant variable stiffness ball joint

This study proposes a novel design of monolithic compliant variable torsional stiffness (VTS) mechanism whose stiffness can be tuned continuously. This mechanism is then used to create a compliant variable stiffness (VS) ball joint. This compliant VS ball joint can be beneficial in various applications such as exoskeletons, prostheses, and bio...

Constant Torque Mechanism for Gravity Balancing in Wrist Support Application

Individuals suffering from neuromuscular conditions, such as Duchenne muscular dystrophy (DMD), experience a progressive weakening of muscles. During the progression, the affected patients require supporting devices like orthoses or exoskeletons to perform their daily activities. Although immense efforts are put into the development of...

A slender compliant mechanism for back support with non-linear behavior

This work aims to achieve a softening moment-angle response by utilizing compliant parts. The approach uses the principle of contact release, which involves initially prestressed torsional bars arranged in series, separated by rigid bodies. By stepwise activation of the torsional bars, a softening behavior is achieved. Mechanical stops are...

The use of a rigid linkage balancer with torsion springs to realize nonlinear moment-angle characteristics

In this work, the possibilities to approach various nonlinear moment-angle characteristics with a kinematically indeterminate rigid body balancer with torsion springs are examined. These torsion springs are mounted on the axes that intersect the rigid bodies. The rigid body balancer is coupled to an inverted pendulum. Although the kinematic...

Slender compliant mechanism with a low axial-bending stiffness ratio for use in an exoskeleton

This project presents a compliant slender mechanism with a low axial-bending stiffness ratio. This can be used in passive exoskeletons. Passive exoskeletons can assist people with their work by preventing injuries. Currently exoskeletons uses sliders to account for the extension of the spine when bending, but this could be uncomfortable. The...

Compliant curved beam transmission systems

This report proposes a concept for an I-profile curved beam compliant transmission system. The application of this system can be as a hip connection within a passive exoskeleton in which it transfers the walking motion from one leg to another. To obtain the desired behavior the torsion stiffness is reduced and the amount of work needed to move...

Towards Neutrally Stable Compliant Shells

Elastic neutral stability involves elastic deformation without stiffness or loads. It is a remarkable appearance, since the deformation of materials is normally associated with an increase of potential energy and a resulting opposing reaction force or moment. Neutrally stable mechanisms can be used to overcome unnecessary actuation which makes...