Bistable Deployable Composite Boom (Bi-DCB) can achieve bistable function by storing and releasing strain energy, which has a good application prospect in space field. For example, it serves as the main support section of deployable structures (e.g., solar arrays and antennas). This paper investigates folding stable state of Bi-DCB through the analytical method. Based on Archimedes’ helix and energy principle, an analytical model for predicting folding stable state of Bi-DCB was presented. The failure index of Bi-DCB in folding stable state were analyzed using the Tsai‐Hill criterion and the maximum stress criterion. Then, a 2400 mm long Bi-DCB was fabricated using autoclave method. The prediction results of the proposed model were compared with experiments and results of two other analytical models. It is shown that the proposed model shows good prediction accuracy. Finally, the effect of geometric parameters on folding stable state of Bi-DCB was further investigated with the aid of the proposed model.

Compared with traditional additive manufacturing technology (3D printing), 4D printing technology (four-dimensional printing) increases the time dimension. The structure prepared by 4D printing process can change its shape and configuration with the external environment (i.e. light, heat, magnetism, electricity, etc.), which has a broad application prospect. This paper introduces several typical implementation methods of 4D printing in combination with the typical research results of 4D printing in recent years. The printing materials, design methods, and simulation methods of current 4D printing technology are summarized. Finally, the possible development directions of 4D printing technology and its application prospects in the fields of biomedicine, soft robotics, aerospace, etc. are introduced, and some problems of 4D printing technology are discussed.