Foldable tubular element with one rigid degree of freedom

A foldable tubular construct with one rigid degree of freedom, comprising a plurality of layered tubular units each with an enclosing side wall, a head rim and tail rim, said enclosing side wall being formed by n side faces, said head rim and said tail rim each defining an n-sided polygon, said side faces each being a rigid planar quadrilateral with two opposing sides forming two side jointing lines with corresponding sides of two adjacent faces of a same tubular unit and another side forming a base joining line with a corresponding side of an adjacent face of a different tubular unit, said plurality of layered tubular units being joined sequentially wherein a head-to-head connection is formed between the head rim of a tubular unit and the head rim of a preceding adjacent tubular unit and/or a tail-to-tail connection is formed between the tail rim of said tubular unit and the tail rim of a following adjacent tubular unit;

• each of said tubular unit has exactly n side joining lines, all parallel to each other;
• said head-to-head connection or tail-to-tail connection consists of n base joining lines interconnected to form an n-sided polygon within a same plane;
• two side joining lines and two base joining lines join at one end to form an apex;
• exactly n apexes are formed in each head-to-head connection or tail-to-tail connection;
• and n is a number greater than 3.