## 4 Conclusions  
This study investigates the bending behavior of various lattice structures, including chiral geometries like lozenge and clepsydra, wavy shapes such as roller and Es, circular-element designs like double hoop and hoop, and a traditional honeycomb pattern. All structures were produced with 50% density. An initial three-point bending test was conducted at a speed of 2 mm/min with a support span of 128 mm, as specified by the testing standard. The specimens underwent cyclic loading, including bending, spring back, and shape recovery phases, to assess their performance at or near the glass transition temperature. Recovery was specifically tested at 55 \({}^{\circ}\)C. Each geometry was initially evaluated with a 16 mm displacement, using two replicates per type. The following results were achieved:  
* Among the tested structures, lozenge and double hoop exhibited the highest mechanical strength, while honeycomb and clepsydra showed inconsistent results.
* In terms of spring back, lozenge and hoop demonstrated limited elastic return, whereas honeycomb and clepsydra displayed more pronounced recovery. The lozenge structure, in particular, exhibited minimal deformation, which contributed to its reduced spring back.
* Thermal-induced shape recovery via immersion in a hot bath did not yield consistent results across most structures, except for the roller, which consistently showed good recovery both in quantity and repeatability. Despite the relatively mild thermal input, repeated cycles in quick succession tended to overstress the specimens, likely due to hydrostatic pressure effects.
* Mechanically, the roller and lozenge performed best in the second and third cycles, with noticeable improvements in energy absorption. As a result, three full cycles of loading, spring back, and recovery were performed. Both the roller and lozenge remained structurally intact throughout. However, the lozenge reached higher peak loads in all cycles, while the roller maintained more stable stress and recovery behavior. The lozenge's shape recovery in later cycles was partially hindered by hydrostatic forces, slightly compromising its elastic response.
* The lozenge absorbed the highest amount of energy overall, whereas the roller showed the smallest decrease in absorbed energy between the second and third cycles. Both structures ultimately demonstrated strong mechanical performance and efficient energy absorption.  
Figure 16: Energy absorption.  
For future investigations, it is recommended to extend the thermal stimulus duration to enhance shape recovery stability. Increasing the number of cycles would also provide further insight into the long-term mechanical behavior of these geometries. In addition, for future studies, it is necessary to increase the number of replicates to statistically validate the results. The results suggest promising applications in smart packaging, where lightweight, recoverable, and energy-absorbing materials can offer enhanced protection, thermal responsiveness, and the possibility of reuse through shape recovery after deformation.  
All authors contributed to the study conception and design. Material preparation, data collection, and analysis were performed by [PERSON] and [PERSON]. The first draft of the manuscript was written by [PERSON] and all authors commented on previous versions of the manuscript. The manuscript was revised by [PERSON] and [PERSON]. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Data Availability StatementData are available on reasonable request.  
The authors declare no conflicts of interest.