Programmable multi-scale fluidic artificial muscles and pistons

A method for converting a pressure difference into a displacement or rotation using a tension piston, the method comprising:

• providing a tension piston system, comprising:
• A) a chamber;
• B) a piston contained in the chamber, the piston comprising:
• i) a collapsible skeleton;
• ii) a flexible skin in which the collapsible skeleton is contained and that, at least in part, defines (a) a volume inside the piston in which the collapsible skeleton is contained and (b) a volume outside the piston yet inside the chamber, wherein the flexible skin seals the volume inside the piston from the volume outside the piston;
• and
• iii) a connector mounted to the collapsible skeleton or the flexible skin, and configured to be displaced or rotated when at least one of the dimensions of the skeleton changes and to convey that displacement or rotation outside the chamber,
• wherein the chamber includes at least two fluid ports, one in fluid communication with the volume inside the piston and another in fluid communication with volume outside the piston;
• and
• pumping fluid into or out of the chamber via at least one of the fluid ports to collapse or expand the flexible skin and skeleton as the flexible skin provides a pulling force on the collapsible skeleton due to a pressure difference between the volume inside the piston and the volume outside the piston as a result of the pumped fluid.