Korean scientists working with an international team have developed a way to use silver nanowires to create therapeutic heat in a light, flexible material, according to a news release.
Researchers at the Center for Nanoparticle Research, Institute for Basic Science in Seoul avoided past solutions such as carbon nanotubes and gold, which were complex to fabricate and could carry large price tags, according to the release.
Instead, the team used silver nanowires, averaging about 150 nanometers in diameter and about 30 micrometers in length. For comparison, a human hair can range from 17 micrometers to 181 micrometers in diameter. Scientists mixed the silver nanowires into a liquid elastic material that is soft and stretchy when dry, according to the release.
To make sure the material fit snugly to the target area while heating, the researchers created a two-dimensional interlocking coil pattern for mesh structure. The liquid mixture was then poured into a shaped mold, and the silver-elastic mesh was sandwiched between a top and bottom layer of soft, thin insulation, according to the release.
When researchers conducted material flexibility tests in which the mesh was placed on knee and wrist joints, the mesh successfully heated while stretched and curved to fit the joint. Researchers reported the findings in the journal ACS Nano.
According to the release, the material is lightweight, breathable and generates heat on its entire surface area. Traditional thermal therapy devices can be rigid, heavy or lose temperature, the authors wrote in the study abstract, adding that other options must be plugged into a power outlet. The mesh maintains a constant temperature instead of cooling down during use and is battery powered, according to the release. So far, the scientists have made flat mesh that can be connected into a tube, according to the release.
Study abstract: http://pubs.acs.org/doi/abs/10.1021/acsnano.5b02790