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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

(A) NiTiNOL guidewire coated with 20 wt% Magpol. (B) Damaged portions of the coated wire were subjected to recovery in an AMF for 20 min, resulting in shape memory assisted self healing.
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f6: (A) NiTiNOL guidewire coated with 20 wt% Magpol. (B) Damaged portions of the coated wire were subjected to recovery in an AMF for 20 min, resulting in shape memory assisted self healing.

Mentions: A practical application of such coatings is in reusable biomedical devices. As a proof-of-concept of self healing, we coated a NiTiNOL guidewire of diameter 0.8mm with Magpol. The coating was achieved through dip-coating a 20 wt% nanoparticle solution of EVA onto the NiTiNOL guidewire to achieve an outer diameter of 1.2mm. Wear damage was simulated by pulling the guidewire through a plastic ring of slightly larger diameter, as would occur in a practical setting during insertion and removal of the guidewire from the body. The damaged section of the wire was then healed in an AMF for 20 min. First, the protruding portions of the damaged area (indicating plastic deformation) returned to their original shape. With further exposure, the original smooth surface was recovered, resulting in healing (Fig. 6).


Magnetic Field Triggered Multicycle Damage Sensing and Self Healing.

Ahmed AS, Ramanujan RV - Sci Rep (2015)

(A) NiTiNOL guidewire coated with 20 wt% Magpol. (B) Damaged portions of the coated wire were subjected to recovery in an AMF for 20 min, resulting in shape memory assisted self healing.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f6: (A) NiTiNOL guidewire coated with 20 wt% Magpol. (B) Damaged portions of the coated wire were subjected to recovery in an AMF for 20 min, resulting in shape memory assisted self healing.
Mentions: A practical application of such coatings is in reusable biomedical devices. As a proof-of-concept of self healing, we coated a NiTiNOL guidewire of diameter 0.8mm with Magpol. The coating was achieved through dip-coating a 20 wt% nanoparticle solution of EVA onto the NiTiNOL guidewire to achieve an outer diameter of 1.2mm. Wear damage was simulated by pulling the guidewire through a plastic ring of slightly larger diameter, as would occur in a practical setting during insertion and removal of the guidewire from the body. The damaged section of the wire was then healed in an AMF for 20 min. First, the protruding portions of the damaged area (indicating plastic deformation) returned to their original shape. With further exposure, the original smooth surface was recovered, resulting in healing (Fig. 6).

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