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Magnetic Field Triggered Multicycle Damage Sensing and Self Healing.

Ahmed AS, Ramanujan RV - Sci Rep (2015)

Bottom Line: Magpol exhibited a linear strain response upto 150% strain and complete recovery after healing.We have demonstrated the use of this concept in a reusable biomedical device i.e., coated guidewires.Our findings offer a new synergistic method to bestow multifunctionality for applications ranging from medical device coatings to adaptive wing structures.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Nanyang Technological University, 639798, Singapore.

ABSTRACT
Multifunctional materials inspired by biological structures have attracted great interest, e.g. for wearable/ flexible "skin" and smart coatings. A current challenge in this area is to develop an artificial material which mimics biological skin by simultaneously displaying color change on damage as well as self healing of the damaged region. Here we report, for the first time, the development of a damage sensing and self healing magnet-polymer composite (Magpol), which actively responds to an external magnetic field. We incorporated reversible sensing using mechanochromic molecules in a shape memory thermoplastic matrix. Exposure to an alternating magnetic field (AMF) triggers shape recovery and facilitates damage repair. Magpol exhibited a linear strain response upto 150% strain and complete recovery after healing. We have demonstrated the use of this concept in a reusable biomedical device i.e., coated guidewires. Our findings offer a new synergistic method to bestow multifunctionality for applications ranging from medical device coatings to adaptive wing structures.

No MeSH data available.


Related in: MedlinePlus

Model of recoverable strain sensing and self healing in Magpol.(A) Original: Sample shows high crystallinity, BBS molecules aggregated and nanoparticles form links between the polymer chains. (B) After plastic deformation and failure: a decrease in crystallinity, single BBS molecules formed due to disaggregation (resulting in a colour change). (C) Recovery: shape recovery causes recovery of the original dimensions. Polymer chain entanglement at the failure interface results in self healing BBS aggregates also re-form resulting in recovery of the original colour. Further cycles of strain and recovery follow the same pattern described above.
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f7: Model of recoverable strain sensing and self healing in Magpol.(A) Original: Sample shows high crystallinity, BBS molecules aggregated and nanoparticles form links between the polymer chains. (B) After plastic deformation and failure: a decrease in crystallinity, single BBS molecules formed due to disaggregation (resulting in a colour change). (C) Recovery: shape recovery causes recovery of the original dimensions. Polymer chain entanglement at the failure interface results in self healing BBS aggregates also re-form resulting in recovery of the original colour. Further cycles of strain and recovery follow the same pattern described above.

Mentions: Figure 7 illustrates our model of the processes occuring during strain and recovery of Magpol. During plastic deformation, BBS chrompophore aggregates present in the amorphous part of the EVA break up into single molecules with a corresponding change in the emission spectrum. This is also accompanied by alignment of polymer chains and crystallites along the strain direction. The nanoparticles may also act as crosslinkers in the matrix. On triggering heating by exposure to the magnetic field, Magpol recovers its original shape, though some of the crystallites may still retain their orientation. Also, a few molecules of the chromophore may remain in the monomeric form. Subsequent cycles of strain and recovery follow the same path as the first cycle.


Magnetic Field Triggered Multicycle Damage Sensing and Self Healing.

Ahmed AS, Ramanujan RV - Sci Rep (2015)

Model of recoverable strain sensing and self healing in Magpol.(A) Original: Sample shows high crystallinity, BBS molecules aggregated and nanoparticles form links between the polymer chains. (B) After plastic deformation and failure: a decrease in crystallinity, single BBS molecules formed due to disaggregation (resulting in a colour change). (C) Recovery: shape recovery causes recovery of the original dimensions. Polymer chain entanglement at the failure interface results in self healing BBS aggregates also re-form resulting in recovery of the original colour. Further cycles of strain and recovery follow the same pattern described above.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562241&req=5

f7: Model of recoverable strain sensing and self healing in Magpol.(A) Original: Sample shows high crystallinity, BBS molecules aggregated and nanoparticles form links between the polymer chains. (B) After plastic deformation and failure: a decrease in crystallinity, single BBS molecules formed due to disaggregation (resulting in a colour change). (C) Recovery: shape recovery causes recovery of the original dimensions. Polymer chain entanglement at the failure interface results in self healing BBS aggregates also re-form resulting in recovery of the original colour. Further cycles of strain and recovery follow the same pattern described above.
Mentions: Figure 7 illustrates our model of the processes occuring during strain and recovery of Magpol. During plastic deformation, BBS chrompophore aggregates present in the amorphous part of the EVA break up into single molecules with a corresponding change in the emission spectrum. This is also accompanied by alignment of polymer chains and crystallites along the strain direction. The nanoparticles may also act as crosslinkers in the matrix. On triggering heating by exposure to the magnetic field, Magpol recovers its original shape, though some of the crystallites may still retain their orientation. Also, a few molecules of the chromophore may remain in the monomeric form. Subsequent cycles of strain and recovery follow the same path as the first cycle.

Bottom Line: Magpol exhibited a linear strain response upto 150% strain and complete recovery after healing.We have demonstrated the use of this concept in a reusable biomedical device i.e., coated guidewires.Our findings offer a new synergistic method to bestow multifunctionality for applications ranging from medical device coatings to adaptive wing structures.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Nanyang Technological University, 639798, Singapore.

ABSTRACT
Multifunctional materials inspired by biological structures have attracted great interest, e.g. for wearable/ flexible "skin" and smart coatings. A current challenge in this area is to develop an artificial material which mimics biological skin by simultaneously displaying color change on damage as well as self healing of the damaged region. Here we report, for the first time, the development of a damage sensing and self healing magnet-polymer composite (Magpol), which actively responds to an external magnetic field. We incorporated reversible sensing using mechanochromic molecules in a shape memory thermoplastic matrix. Exposure to an alternating magnetic field (AMF) triggers shape recovery and facilitates damage repair. Magpol exhibited a linear strain response upto 150% strain and complete recovery after healing. We have demonstrated the use of this concept in a reusable biomedical device i.e., coated guidewires. Our findings offer a new synergistic method to bestow multifunctionality for applications ranging from medical device coatings to adaptive wing structures.

No MeSH data available.


Related in: MedlinePlus