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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

Change in relative intensities in the photolumenscent spectra of Magpol at 425 and 515 nm (plotted as a ratio IE/IM following strain and shape recovery over 3 cycles).Cycling was done for 12, 16 and 20 wt% filler samples.
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f4: Change in relative intensities in the photolumenscent spectra of Magpol at 425 and 515 nm (plotted as a ratio IE/IM following strain and shape recovery over 3 cycles).Cycling was done for 12, 16 and 20 wt% filler samples.

Mentions: Previous studies have shown the use of mechanochromic molecules as strain sensors in polymers21. However, a significant drawback is the single cycle use. In previous reports, plastic deformation could not be reversed hence the technique was only applicable for one time use26. Other reports demonstrated repeatable sensing in elastomers through chemical modification of the polymer chains47. On the other hand, in our experiments, we use shape memory recovery to reorganize BBS chromophore aggregates as well as to recover from plastic deformation. Magpol, with different filler loading, was subjected to three cycles of plastic deformation (~200%) and recovery in an AMF. The IE/IM ratio was recorded before and after strain deformation as well as after recovery. The percent change in the IE/IM ratio was calculated for each case and recovery was determined (Fig. 4). It was observed that changes in emission spectra upon damage and recovery increased with filler loading.


Magnetic Field Triggered Multicycle Damage Sensing and Self Healing.

Ahmed AS, Ramanujan RV - Sci Rep (2015)

Change in relative intensities in the photolumenscent spectra of Magpol at 425 and 515 nm (plotted as a ratio IE/IM following strain and shape recovery over 3 cycles).Cycling was done for 12, 16 and 20 wt% filler samples.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f4: Change in relative intensities in the photolumenscent spectra of Magpol at 425 and 515 nm (plotted as a ratio IE/IM following strain and shape recovery over 3 cycles).Cycling was done for 12, 16 and 20 wt% filler samples.
Mentions: Previous studies have shown the use of mechanochromic molecules as strain sensors in polymers21. However, a significant drawback is the single cycle use. In previous reports, plastic deformation could not be reversed hence the technique was only applicable for one time use26. Other reports demonstrated repeatable sensing in elastomers through chemical modification of the polymer chains47. On the other hand, in our experiments, we use shape memory recovery to reorganize BBS chromophore aggregates as well as to recover from plastic deformation. Magpol, with different filler loading, was subjected to three cycles of plastic deformation (~200%) and recovery in an AMF. The IE/IM ratio was recorded before and after strain deformation as well as after recovery. The percent change in the IE/IM ratio was calculated for each case and recovery was determined (Fig. 4). It was observed that changes in emission spectra upon damage and recovery increased with filler loading.

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