Implementation Of A Negative Stiffness Mechanism For Variable Stiffness Robots

Abstract
Negative stiffness is a naturally occurring phenomenon which takes place during buckling of beams, that may be exploited to achieve extreme stiffness and damping properties for variable stiffness actuators. This project aims at implementation of a negative stiffness mechanism to be utilized as a part of variable stiffness actuators in robotics. This project gives a guide studying simple models that lead to negative stiffness, constructing several prototypes of such mechanisms by using rapid prototyping techniques and experimentally verifying the range of negative stiffness achieved by each prototype.
Motivation

• Controlling stiffness using a mechanical mechanism that provides variable stiffness which is a more convenient, energy and cost efficient way to generate haptic interfaces.
• Using the negative stiffness characteristics, setting the lowest stiffness arbitrarily close to zero while making very high stiffness values also achievable (Yalcin et al., 2013).