Curvature Change Analysis of SMART Fibers used for Temperature Adaptive Insulation

A. Latulippe, C. Ripa, S. Fossey, C. Drew, H. Sun
University of Massachusetts Lowell,
United States

Keywords: SMART Fibers


A new method of characterizing the curvature change in thermally adaptive fibers is introduced in this paper. Based on the principle of bi-metallic strips commonly found in thermostats, multi-component polymer fibers can be created to change their geometrical form in response to a temperature change. This works by creating fibers from two or more materials that have a mismatched Coefficient of Thermal Expansion (CTE). A temperature change leads to a change in curvature of these fibers. When fibers interact in an insulation structure, a temperature change leads to a thickness change in the insulation. While these fibers have visually been observed to function, up until now there has been no way to quantitatively characterize their curvature performance. This paper introduces a method to quantify curvature performance. Suspending fibers on the surface of a liquid and changing the temperature induces a change in curvature. By analyzing digital images taken with an optical microscope, the radius of curvature is recorded at specific temperatures. This method is used to find performance trends, such as overall performance, time dependent effects as well as the influence that initial curvature at a specific temperature has.