Variable stiffness actuator with electrically modulated stiffness

A variable stiffness actuator (VSA) comprising:

• a plurality of stacked dielectric elastomer system (DES) diaphragm modules, each DES diaphragm module including a variable stiffness membrane comprising a material that will soften when energized and stiffen when not energized;
• a stiffness controller connected to the plurality of stacked DES diaphragm modules and configured to control the stiffness of the DES diaphragm modules;
• an actuator mechanically coupled to the plurality of stacked DES diaphragm modules and configured to control an equilibrium position of the VSA, the actuator configured to move in a direction substantially parallel with a stacked direction of the DES diaphragm modules;
• and
• a connector connecting the plurality of stacked DES diaphragm modules to a load.

A variable stiffness actuator (VSA) comprising:

• a plurality of stacked dielectric elastomer system (DES) diaphragm modules, each DES diaphragm module including a variable stiffness membrane, wherein a first side of each of the variable stiffness membranes is at least partially covered by a first compliant electrode, wherein a second side of each of the variable stiffness membranes is at least partially covered by a second compliant electrode, and wherein each of the variable stiffness membranes is configured to soften when energized with an electric field applied via the first and second compliant electrodes and to become stiffer when unenergized;
• a stiffness controller connected to the plurality of stacked DES diaphragm modules, the stiffness controller configured to control the stiffness of the variable stiffness membranes via application of a control voltage thereto;
• a ball screw;
• an actuator coupled to the ball screw, the actuator configured to adjust an equilibrium position of the VSA by moving in a direction substantially parallel with a stacked direction of the DES diaphragm modules;
• an input block configured to mechanically couple the ball screw to one of inner frames or outer frames of the plurality of stacked DES diaphragm modules;
• an output block configured to mechanically couple the other of the outer frames or the inner frames of the plurality of stacked DES diaphragm modules to an output connection point, the output connection point configured to receive a load.