Abstract: Pneumatic muscles capable of delivering bi-directional forces are described having an actuator with a tube or bladder surrounded by a braided material mounted in parallel with a resilient spring. When the bladder is pressurized with a pneumatic source, it expands, and its length contracts. During the contraction cycle, the resilient spring is compressed and stores energy until subsequently released, which corresponds when the pressure in the bladder is released. As the spring expands, it produces an expansion force. The contraction and expansion forces are controllable using a number of configurations, including changing the equilibrium position of the resilient spring, using a different rated bladder, and using different initial pressure.

Abstract: The present invention is a spring based actuator with a leaf spring having a length, width and thickness and a coil spring positioned over the leaf spring. The coil spring further comprises: a first end; a second end; and at least one force generator acting on either the first end of the coil spring and the second end of the coil spring to deflect the coil spring and the leaf spring.

Abstract: Constant force mechanisms and adjustable constant force mechanisms are described having tow movable sliders constrained along two perpendicular axes and each abutting a resilient member. The mechanisms are adapted to produce an output force that is constant for a given input force. However, when an equilibrium position of one of the two resilient members is adjusted for a given mechanism, a different output force will result. Micro-compliant mechanisms are also described in which the resilient members may be made from one or more different elastomers.