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Sequential Self-Folding Structures by 3D Printed Digital Shape Memory Polymers.

Mao Y, Yu K, Isakov MS, Wu J, Dunn ML, Jerry Qi H - Sci Rep (2015)

Bottom Line: A simplified reduced-order model is also developed to rapidly and accurately describe the self-folding physics.An important aspect of self-folding is the management of self-collisions, where different portions of the folding structure contact and then block further folding.A metric is developed to predict collisions and is used together with the reduced-order model to design self-folding structures that lock themselves into stable desired configurations.

View Article: PubMed Central - PubMed

Affiliation: The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.

ABSTRACT
Folding is ubiquitous in nature with examples ranging from the formation of cellular components to winged insects. It finds technological applications including packaging of solar cells and space structures, deployable biomedical devices, and self-assembling robots and airbags. Here we demonstrate sequential self-folding structures realized by thermal activation of spatially-variable patterns that are 3D printed with digital shape memory polymers, which are digital materials with different shape memory behaviors. The time-dependent behavior of each polymer allows the temporal sequencing of activation when the structure is subjected to a uniform temperature. This is demonstrated via a series of 3D printed structures that respond rapidly to a thermal stimulus, and self-fold to specified shapes in controlled shape changing sequences. Measurements of the spatial and temporal nature of self-folding structures are in good agreement with the companion finite element simulations. A simplified reduced-order model is also developed to rapidly and accurately describe the self-folding physics. An important aspect of self-folding is the management of self-collisions, where different portions of the folding structure contact and then block further folding. A metric is developed to predict collisions and is used together with the reduced-order model to design self-folding structures that lock themselves into stable desired configurations.

No MeSH data available.


(a) The schematic graph of the interlocking SMP component. (b) The ROM simulation of the sequential folding resulting in interlocking, and (c) the collision indices of the chosen design. (d) The comparison of experiments (plan and side views) and the ROM simulations (red lines).
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f5: (a) The schematic graph of the interlocking SMP component. (b) The ROM simulation of the sequential folding resulting in interlocking, and (c) the collision indices of the chosen design. (d) The comparison of experiments (plan and side views) and the ROM simulations (red lines).

Mentions: Here we use our ROM to design and then 3D print a self-folding and self-locking structure, as shown in Fig. 5a. While this locking structure demonstrates the importance of controlling the folding sequence and how more complex structure folding can be obtained, we could also pursue other kinematic objectives such as making stops, kickstands, etc. Here, two holes with different dimensions are designed on one of the end panels. The objective is to sequentially guide the other end of the structure through the first hole and then through the second hole to lock the structure in place. The thickness of the SMP components is 0.6 mm (0.8 mm for the plates with holes) and the depth is 6 mm. Five hinges (with a radius of 5 mm in uniform) are used.


Sequential Self-Folding Structures by 3D Printed Digital Shape Memory Polymers.

Mao Y, Yu K, Isakov MS, Wu J, Dunn ML, Jerry Qi H - Sci Rep (2015)

(a) The schematic graph of the interlocking SMP component. (b) The ROM simulation of the sequential folding resulting in interlocking, and (c) the collision indices of the chosen design. (d) The comparison of experiments (plan and side views) and the ROM simulations (red lines).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562068&req=5

f5: (a) The schematic graph of the interlocking SMP component. (b) The ROM simulation of the sequential folding resulting in interlocking, and (c) the collision indices of the chosen design. (d) The comparison of experiments (plan and side views) and the ROM simulations (red lines).
Mentions: Here we use our ROM to design and then 3D print a self-folding and self-locking structure, as shown in Fig. 5a. While this locking structure demonstrates the importance of controlling the folding sequence and how more complex structure folding can be obtained, we could also pursue other kinematic objectives such as making stops, kickstands, etc. Here, two holes with different dimensions are designed on one of the end panels. The objective is to sequentially guide the other end of the structure through the first hole and then through the second hole to lock the structure in place. The thickness of the SMP components is 0.6 mm (0.8 mm for the plates with holes) and the depth is 6 mm. Five hinges (with a radius of 5 mm in uniform) are used.

Bottom Line: A simplified reduced-order model is also developed to rapidly and accurately describe the self-folding physics.An important aspect of self-folding is the management of self-collisions, where different portions of the folding structure contact and then block further folding.A metric is developed to predict collisions and is used together with the reduced-order model to design self-folding structures that lock themselves into stable desired configurations.

View Article: PubMed Central - PubMed

Affiliation: The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.

ABSTRACT
Folding is ubiquitous in nature with examples ranging from the formation of cellular components to winged insects. It finds technological applications including packaging of solar cells and space structures, deployable biomedical devices, and self-assembling robots and airbags. Here we demonstrate sequential self-folding structures realized by thermal activation of spatially-variable patterns that are 3D printed with digital shape memory polymers, which are digital materials with different shape memory behaviors. The time-dependent behavior of each polymer allows the temporal sequencing of activation when the structure is subjected to a uniform temperature. This is demonstrated via a series of 3D printed structures that respond rapidly to a thermal stimulus, and self-fold to specified shapes in controlled shape changing sequences. Measurements of the spatial and temporal nature of self-folding structures are in good agreement with the companion finite element simulations. A simplified reduced-order model is also developed to rapidly and accurately describe the self-folding physics. An important aspect of self-folding is the management of self-collisions, where different portions of the folding structure contact and then block further folding. A metric is developed to predict collisions and is used together with the reduced-order model to design self-folding structures that lock themselves into stable desired configurations.

No MeSH data available.