A dovetailed building block includes a block body having a plurality of side surfaces. The side surfaces are constructed in an order of having a side surface with a dovetailed recess next to another surface with a dovetailed projection. The dovetailed projection of one said block body can engage the corresponding dovetailed recess of another said block body in a 90-degree cross manner. Thereupon, while in stacking a plurality of the block bodies, variety of secured and stable three-dimensional curved configuration can be built through angular engagement of one dovetailed projection of one block body and another dovetailed recess of another block body.

An interlocking disc includes a hub with an inner circular area with an inner thickness and a circular step. A plurality of petals circumferentially spaced apart extend radially outward from the outer area of the hub. Each of the plurality of petals are disposed within a common plane and include a catch on each of side of each petal. The catch is engageable to a circular stop of another interlocking disc to inhibit disassembly.

An improved swim noodle system is described. The system has a first interlocking swim noodle including a first central core defining a first longitudinal axis coaxial with the first central core and a first periphery disposed about the first central core. The first elongated swim noodle further comprises alternating nodes and alcoves disposed about an entirety of the first periphery. The first nodes diverge outwardly from the first central core and extend longitudinally generally parallel to the first longitudinal axis. The first alcoves converge outwardly from the first central core and extend longitudinally generally parallel to the first longitudinal axis. The first nodes and the first alcoves are arranged to mate by resistance fit with the second elongated swim noodle.

A three-dimensional transformable structure containing a set of individual elementary components, so-called IECs, forming a single-piece assembly. An IEC includes an active or inert material and at least one portion of the set of IECs includes at least three connecting means. Each connecting means of a considered IEC is arranged to cooperate with at least one connecting means of an IEC adjacent to the considered IEC to connect the considered IEC to the adjacent IEC. For the at least one portion of the set of IECs, at least one of the connecting means of a given IEC is located on a side opposite to at least another one of the connecting means of the considered IEC. At least one portion of the set of IECs includes so-called active IECs spatially arranged in the transformable structure so that at least one property of the transformable structure is modified in response to the application of at least one stimulus.

A ball joint connector for an interlocking disc is disclosed having a ball connector. The ball connector has a ball, a shaft, and a fork. The ball and the fork are connected by the shaft. The fork comprises a first prong and a second prong disposed in a common plane, and a notch formed between the first prong and the second prong. Each prong comprises a catch on an interior wall facing the other prong. The ball joint connector may have a cup connector comprising a cup, a second shaft, and a second fork. The cup and the second fork are connected by the second shaft. The second fork comprises a plurality of second prongs.