Antagonistic variable stiffness elements

The concept of variable stiffness elements based on antagonistic forces (prestress) in cable-driven mechanisms is presented and the fundamental challenges are identified and addressed including: (1) the relative significance of the antagonistic stiffness versus the structural stiffness, and (2) the extent of the antagonistic stiffness. The feasibility of the idea is also shown by a conceptual design of an adaptive engine mount using variable antagonistic stiffness.