Shape-morphing space frame apparatus using unit cell bistable elements

A method of fabricating predictable and controllable length or shape changes in a bistable, shape-morphing mechanism, allowing the morphing from an initial specific shape into a resulting specific shape that is different from said initial specific shape, without use of a hard stop, said method comprising:

• identifying said initial specific shape and said resulting specific shape;
• providing a plurality of nodes and a plurality of links, said plurality of nodes interconnecting said plurality of links in said initial specific shape, wherein said plurality of links do not change length between said initial specific shape and said resulting specific shape, said plurality of nodes including fixed ground pivots and moving pivots, said plurality of links including fixed links and moving links;
• identifying a first attachment point of a non-interfering potential energy element to be positioned on a fixed link;
• identifying a second attachment point of said potential energy to be positioned on a moving link;
• said first and second attachment points based on a path of travel of said potential energy element between said initial and resulting specific shapes;
• positioning said potential energy element between two moving pivots to provide a degree-of-freedom during actuation of said bistable mechanism between said initial specific shape and said resulting specific shape, wherein a potential energy of said potential energy element is minimized in said initial and resulting specific shapes and increases during transition between said initial and resulting specific shapes, wherein said potential energy element is capable of generating sufficient potential energy to overcome any restoring torques within said moving pivots when transitioning between said initial specific shape and said resulting specific shape;
• and
• fabricating said bistable, shape-morphing mechanism based on the foregoing steps.

A shape-morphing space frame apparatus using unit cell bistable elements, comprising:

• a first structural framework formed of a plurality of nodes and a plurality of links, including at least one bistable link,
• said first structural framework having a first stable position and a second stable position, said first structural framework further having a first quadrilateral-shaped constraint in said first stable position and a second quadrilateral constraint in said second stable position, said first quadrilateral-shaped constraint being different from said second quadrilateral-shaped constraint for said first structural framework,
• said first structural framework having a first end and a second end;
• a first plurality of second structural frameworks each formed of a plurality of nodes and a plurality of links, including at least one bistable link,
• said each second structural framework of said first plurality of second structural frameworks having a first stable position and a second stable position, said each second structural framework further having a first quadrilateral-shaped constraint in said first stable position and a second quadrilateral constraint in said second stable position, said first quadrilateral-shaped constraint being different from said second quadrilateral-shaped constraint for said each second structural framework of said first plurality of second structural frameworks,
• wherein said first plurality of second structural frameworks are adjacent to each other, collectively have a first curvature in said first stable position, and collectively have a second curvature in said second stable position, such that said second curvature is greater or less than said first curvature,
• said first plurality of second structural frameworks collectively having a first end and a second end;
• a second plurality of second structural frameworks each formed of a plurality of nodes and a plurality of links, including at least one bistable link,
• said each second structural framework of said second plurality of second structural frameworks having a first stable position and a second stable position, said each second structural framework further having a first quadrilateral-shaped constraint in said first stable position and a second quadrilateral constraint in said second stable position, said first quadrilateral-shaped constraint being different from said second quadrilateral-shaped constraint for said each second structural framework of said second plurality of second structural frameworks,
• wherein said second plurality of second structural frameworks are adjacent to each other, collectively have a first curvature in said first stable position, and collectively have a second curvature in said second stable position, such that said second curvature is greater or less than said first curvature,
• said second plurality of second structural frameworks collectively having a first end and a second end,
• said first end of said first plurality of second structural frameworks coupled to said first end of said first structural framework, said first end of said second plurality of second structural frameworks coupled to said second end of said first structural framework, and said second end of said first plurality of second structural frameworks coupled to said second end of said second plurality of second structural frameworks,
• such that said apparatus is a curved triangular prism in a first stable position and also is a curved triangular prism in a second stable position, wherein a bistability of said apparatus is achieved by said at least one bistable link in each framework of said first structural framework, said each second structural framework of said first plurality of structural frameworks, and said each second structural framework of said second plurality of structural frameworks.